- Email: [email protected]
Does taping influence electromyographic muscle activity in the scapular rotators in healthy shoulders?
Manual Therapy (2002) 7(3), 154–162 # 2002 Elsevier Science Ltd. All rights reserved. doi:10.1054/math.2002.0464, available online at http://www.idealibrary.com on
Original article
Does taping influence electromyographic muscle activity in the scapular rotators in healthy shoulders? A. M. Cools, E. E. Witvrouw, L. A. Danneels, D. C. Cambier Department of Rehabilitation Sciences and Physiotherapy & Postgraduate Education in Manual Therapy, Faculty of Medicine and Health Sciences, University Hospital, Ghent, Belgium
SUMMARY. Although taping techniques are commonly used in addition to exercise programmes in the rehabilitation of shoulder instability and secondary subacromial or internal impingement, few studies exist on the effect of taping on the muscle activity of the scapular rotators. The purpose of our study was to examine the influence of one particular tape on muscular activity in scapular muscles. Twenty healthy shoulders were examined with surface EMG recordings on the three parts of trapezius and serratus anterior muscle during dynamic full range of motion abduction and forward flexion. The movement direction, and tape and no-tape conditions were randomized. The statistical analyses with ANOVA repeated Measures (GLM model) showed significant differences among the means between the four muscles (Po0.05), two movement directions (Po0.05), applied resistance (Po0.01), and movement period (Po0.01). However, no significant difference was observed based on the application of tape. The results of our investigation revealed no significant influence of tape application on EMG activity in the scapular muscles in healthy subjects. Future research will be necessary to examine other parameters of neuromuscular control in order to determine possible proprioceptive changes in muscle recruitment with tape application. r 2002 Elsevier Science Ltd. All rights reserved.
Most authors agree that the effect of tape can only partially be explained by increased mechanical stability (Wilkerson 1991; Bockrath et al. 1993; Bennell & Goldie 1994, Larsen et al. 1995; Kowall et al. 1996; Somes et al. 1997; Gilleard et al. 1998; Lohrer et al. 1999; McCaw & Cerullo 1999). It is suggested, however, that taping may have some proprioceptive influences. Therefore, if taping techniques do give joint protection, it is now thought that they act by improving proprioception rather than by restricting movement (Karllson & Andreasson 1992; Heit et al. 1996; Robbins & Waked 1998). The effectiveness of various taping techniques was studied extensively in the knee (Anderson et al. 1992; Bockrath et al. 1993; Larsen et al. 1995; Kowall et al. 1996; Gilleard et al. 1998), and the ankle (Wilkerson 1991; Karlsson & Andreasson 1992; Lohrer et al. 1999; McCaw & Cerullo 1999). Although the influence of taping on neuromuscular function is often suggested, the underlying mechanism is still unclear. Some authors found changes in the onset of muscle activity in the knee with tape (Karlsson & Andreasson 1992; Gilleard et al. 1998). They assumed that changes in latency times might be the result of cutaneous stimulation effected by the
INTRODUCTION The application of taping is widely used among athletes both in the rehabilitation and in the prevention of sports injuries (Engstro¨m & Renstro¨m 1998; Robbins & Waked 1998). The basic rationale for taping is to provide protection and support for a joint while permitting optimal functional movement. It is assumed that external support increases joint stability by reinforcing the ligaments and restricting motions. However, various authors mention that the support function of taping is lost within a relatively short time after application (Greene & Wight 1990; Gross et al. 1994; Lohrer et al. 1999). Received: 28 January 2002 Revised: 13 May 2002 Accepted: 5 June 2002 Ann M. Cools, PT, candidate for a doctoral degree, Erik E. Witvrouw, PT, PhD, Lieven A. Danneels, PT, PhD, Dirk C. Cambier, PT, PhD, Director, Department of Rehabilitation Sciences and Physiotherapy, Ghent University, Ghent, Belgium. Correspondence to: AC, Department of Rehabilitation Sciences and Physiotherapy & Postgraduate Education in Manual Therapy, University Hospital Ghent, De Pintelaan 185, 1B3, B9000 Ghent, Belgium. Tel.: +32/240 26 32; Fax: +32/240 38 11 E-mail: [email protected] 154
Taping and electromyographic muscle activity in shoulders 155
tape. This theory supposes that traction on the skin or the pressure of the tape provides cutaneous sensory cues, thus providing additional proprioceptive input to the central nervous system. Recently, various taping techniques of the scapula have been introduced into the conservative management of the shoulder girdle (Host 1995; Mottram 1997; Hall 1999; Schmitt & Snyder-Mackler 1999). The purpose of these techniques is to normalize the scapulohumeral rhythm by influencing the scapular muscle activity and correcting abnormal scapular position. Scapulothoracic dysfunction is often seen in patients with shoulder problems or cervicobrachial pathologies (Glousman et al. 1988; Kamkar et al. 1993; Host 1995; Rupp et al. 1995; McMahon et al. 1996; Arrayo et al. 1997; Blevins 1997; Mottram 1997; Wadsworth & Bullock-Saxton 1997; Kibler 1998; Lukasiewicz et al. 1999; Schmitt & SnyderMackler 1999; Pink & Tibone 2000; Sahrmann 2002). A current belief is that weakness of the scapular musculature will affect normal scapular positioning. It has been suggested that if excessive motion of the scapula occurs, this may place increased stress on the glenohumeral capsular structures and lead to increased glenohumeral instability. Malpositioning of the scapula for any given arm configuration may also influence the instantaneous centre of shoulder rotation, which can significantly alter moments of force generation about the shoulder (McQuade et al. 1998). Scapulothoracic muscle weakness, and hence the lack of scapular stability, has also been identified as a cause of secondary subacromial impingement syndrome (Kamkar et al. 1998; Kibler 1998; Schmitt & Snyder-Mackler 1999). Although much of the conservative management of patients with shoulder impingement is predicated upon correction of faulty and aberrant scapular motion patterns, quantitative evidence documenting specific patterns of abnormal scapular motions in this patient group is still quite limited (Lukasiewicz et al. 1999). Some authors (Pink et al. 1991; Kelley 1995) state that muscular imbalance in throwing athletes, frequently consist of overcompensation of the scapular elevators. This increased upper trapezius activity can lead to hypertrophy and constant tension overload in these muscle fibres. Others (Kamkar et al. 1993; Host 1995; Kibler 1998) suggest that insufficient upward rotation of the scapula, causing a lack of appropriate acromial elevation during overhead shoulder motion such as throwing, may contribute to secondary subacromial impingement. A relative decrease in the subacromial space due to functional scapulothoracic instability would be the underlying mechanism. According to Blevins (1997), limited upward rotation of the scapula is a contributing factor to internal or superior glenoid impingement. The pinching of the posterior–superior rotator cuff tendons between the humerus and the posterior–superior glenoid rim may # 2002 Elsevier Science Ltd. All rights reserved.
be caused by a lack of scapular elevation and retraction in the cocking position. Although taping techniques are commonly used in addition to exercise programmes in the rehabilitation of shoulder instability and secondary subacromial or internal impingement, few studies exist on the effect of taping on the muscle activity of the scapular rotators. Therefore, the purpose of this study was to examine the influence of tape application on muscular activity in scapular muscles (three trapezius parts and serratus anterior) during a dynamic abduction and forward flexion movement.
MATERIALS AND METHODS Subjects Twenty healthy male subjects volunteered to participate in this study. Exclusion criteria were current or past history of shoulder pain, shoulder instability or chronic cervicobrachial pain symptoms, and participation in overhead sports. The mean age of the group was 22.15 years (range 20–25), mean body weight 71.35 kg (range 61–90), and mean height 180.74 cm (range 169–188). Fifteen subjects were right handed, five were left handed. The dominant shoulder was tested in all subjects. All subjects signed an informed consent before participating in the investigation. The study was approved by the Ethical Committee of Ghent University. Materials Prior to electrode application, the skin was prepared with alcohol to reduce skin impedance (typically o10 kO). Bipolar surface electrodes (Blue Sensors – Medicotest, Denmark) were placed with a 1 cm interelectrode distance over the upper, middle and lower portions of the trapezius muscle and the lower portion of the serratus anterior. All electrodes were placed according to the protocol described by Basmajian and De Luca (1985), although the electrode position of the upper trapezius was slightly medialized, thus allowing proper tape application on the muscle belly (Fig. 1). Electrodes for the upper trapezius were placed midway between the spinous process of the seventh cervical vertebra and the posterior tip of the acromion process along the line of the trapezius. The middle trapezius electrode was placed midway on a horizontal line between the root of the spine of the scapula and the thoracic spine. The lower trapezius electrode was placed obliquely upward and laterally along a line between the intersection of the spine of the scapula with the vertebral border of the scapula and the seventh thoracic spinous process. The serratus anterior electrode was placed midway between the lateral, Manual Therapy (2002) 7(3), 154–162
156 Manual Therapy
Fig. 2 Fig. 1
inferior border of the scapula and the insertion of the muscle on the anterio-lateral side of the thorax. A reference electrode was placed over the clavicle. Each set of bipolar recording electrodes on each of the four muscles was connected to a Noraxon Myosystem 2000 electromyographic receiver (Noraxon USA, Inc., Scottsdale, AZ). The sampling rate was 1000 Hz. All raw myo-electric signals were preamplified (overall gain = 1000, common rate rejection ratio 115 dB, signal-to-noise ratio o1 mV RMS baseline noise, filtered to produce a bandwidth of 10–1000 Hz). A strip of Fixomull stretch (Beiersdorfs) was applied over the muscle belly of the upper trapezius, starting anterior just proximal to the clavicle. The tape was firmly pulled over the belly of the upper trapezius, meanwhile giving a skin traction on the soft tissue towards the cervical spine. On the posterior side of the trunk, the tape was attached towards the thoracic spine, following the muscle fibres of the lower trapezius. The same procedure was repeated with a leukotape P strip (Beiersdorfs) (McConnell 1999). All the taping applications were performed by the same researcher, who is experienced in the procedure (Fig. 2). Testing procedure The testing session started with a warm-up procedure, consisting of shoulder movements in all directions, push-up-exercises against the wall and stretching exercises for the rotator cuff and scapular muscles. Then verification of EMG signal quality was completed for each muscle by having the subject perform isometric contractions in manual muscle test positions specific to each muscle of interest (Kendall & Kendall 1983). Subjects performed three 5-s maximum voluntary isometric muscle contractions against manual resistance by the principal investigator. A 5-s pause occurred between muscle contracManual Therapy (2002) 7(3), 154–162
tions (Hancock & Hawkins 1996, De Luca 1997). As a normalization reference, EMG data were collected during maximal voluntary contraction (MVC) for each muscle. After signal filtering with a low-pass filter (single pass, Butterworth, 6 Hz low-pass filter of the 6th order) and visual inspection for artefacts, the peak average EMG value over a window of 1 s was calculated for each trial. Further calculations were performed with the mean of the repeated trials as a normalization value (100%) (Danneels et al. 2001). To avoid alterations in muscle activity of the upper trapezius caused by head position or movement, the subjects were instructed to look in front of them while testing. Two movements were performed during the test: abduction in the frontal plane, and forward flexion in the sagittal plane. Each movement was performed over the whole range of motion in a rhythm of 4 s:2 s of concentric contraction and upward movement, and 2 s of eccentric contraction and downward movement, with 4 s of rest between trials. The rhythm was set by a metronome and controlled by the examiner’s counting. Prior to starting collecting data, subjects were allowed five practice trials to ensure they completed the arm movement in a 4 s rhythm, as set by the metronome. Following the practice trials, the subject completed three trials of each movement. The second movement was used for further analysis. Each movement was performed with and without an external resistance, and in a tape and a no-tape condition. The weight resistance was set at 2 kg for a body weight between 50 and 60 kg, 2.5 kg for a body weight between 70 and 80 kg, and 3 kg if the person weighed more than 80 kg. The test conditions tape/ no-tape and abduction/forward flexion were randomized. Signal processing All raw EMG signals were analogue/digital (A/D) converted (12-bit resolution) at 1000 Hz. Signals then # 2002 Elsevier Science Ltd. All rights reserved.
Taping and electromyographic muscle activity in shoulders 157
were digitally full-wave rectified and low-pass filtered (single pass, Butterworth, 6 Hz low pass filter of sixth order). Results were normalized to the maximum activity observed during the maximal voluntary trials. After rectifying, filtering and normalization, further analysis was performed on four periods during arm movement, each of 1-s duration. Periods were defined by markers, automatically placed on the EMG signal with every metronome signal. The mean amplitude EMG signal, expressed as a percentage of maximal voluntary contraction, was used to assess the activity of the three trapezius parts and serratus anterior muscle in each condition and each period. Statistical analysis Differences in EMG activity among the several conditions were analysed with an univariate approach to repeated measures analysis of variance (General Linear Model), in which the within-subject factors were: (1) muscle, (2) movement direction (3) resistance, (4) tape, and (5) period. The alpha-level for the ANOVA was set as 0.05. In case of significant differences, paired t-tests with Bonferroni correction were used for post-hoc multiple pairwise comparisons. All statistical analysis was performed with the Statistical Package for Social Sciences (SPSS), version 9.0.
RESULTS The results of the descriptive statistical analyses are summarized in Table 1 for the abduction movement with and without external resistance, and Table 2 for the forward flexion movement, with and without external resistance. The statistical analysis with ANOVA repeated measures General Linear and Model (GLM) showed significant differences in EMG activity based on the factors muscle (Po0.01), movement direction (Po0.01), resistance (Po0.01), and period (Po 0.01), but no significant difference based on the application of tape (P = 0.578). The analysis of interaction effects for the muscle factor revealed significant muscle movement direction interaction effect (Po0.05), and no significant interaction for muscle period (P = 0.126) and muscle resistance (P = 0.720). There was no significant interaction between the tape factor and any other factor in the GLM. The results show that the application of tape has no influence on EMG activity in all conditions, and differences in EMG activity based on all other factors are independent of tape application (no tape other factor interaction). Since the influence of tape on EMG activity for the four muscles was of particular interest, and the ANOVA showed no significant differences based on # 2002 Elsevier Science Ltd. All rights reserved.
the application of tape, further post-hoc analyses on the factor tape were not performed.
DISCUSSION Normal muscle activity of the scapular rotators allows for normal kinematics of the scapular movement. The role of the scapular muscles is to promote glenohumeral stability, to provide a stable basis from which other muscles can operate in an optimal length–tension relationship, and to elevate the acromion during arm elevation in order to prevent impingement (Wilk & Arrigo 1993; Mottram 1997). In addition, the scapula plays an important role of being a link in the kinetic chain of proximal to distal sequencing of velocity, energy and forces in many shoulder activities such as throwing (Kibler 1998). Anatomic and histochemical studies regarding trapezius muscle composition found some functional subdivisions within the trapezius muscle. Lindman et al. (1990, 1991) found that the ascending portion of the trapezius muscle (arising from the spinous processes and interspinous ligaments of approximately the T4–T12 vertebrae, and attaching in the region of the tubercle at the medial end of the spine of the scapula) had a predominance of type I fibres, whereas the most superior parts of pars descendens (from the medial third of the superior nuchal line and the ligamentum nuchae to the posterior border of the lateral third of the clavicle) had a higher frequency of type II fibres. These differences in fibre type might reflect different functional demands on the trapezius muscle parts in various head, neck, and shoulder movements. The author concluded that the lower trapezius seems best suited for postural and stabilizing functions in the shoulder and arm movements, whereas the upper trapezius seems best suited for phasic activities. Similar conclusions can be drawn from a dissection study revealing the fascicular anatomy of the trapezius (Johnson et al. 1994). Based on the orientation of the fibres of the lower trapezius, it was suggested that the role of the lower part of the trapezius is more consistent with maintaining horizontal and vertical equilibrium of the scapula rather than generating net torque. In addition, Johnson et al. (1994) hypothesized that the thoracic fibres of the trapezius muscle do not appreciably change length throughout the entire range of upward rotation of the scapula. Hence, the contribution of the lower trapezius to net torque about the axis of rotation of the scapula was thought to be limited. The upper fibres of trapezius exert an upward rotation moment about this axis, complementing that of the serratus anterior. Wadsworth and Bullock-Saxton (1997) examined the temporal recruitment patterns of the scapular rotator muscles during controlled voluntary abduction in the scapular plane. Their Manual Therapy (2002) 7(3), 154–162
Upper trapezius
No resistance, no tape No resistance, tape Resistance, no tape Resistance, tape
Middle trapezius
Lower trapezius
Serratus anterior
P1
P2
P3
P4
P1
P2
P3
P4
P1
P2
P3
P4
P1
P2
P3
P4
9.8 (74.3) 10.9 (76.4) 19.8 (711.1) 22.3 (711.2)
28.8 (710.5) 29.6 (711.3) 51.7 (716.6) 51.7 (717.9)
21.9 (710.9) 22.7 (78.6) 32.1 (711.7) 34.7 (713.3)
12.2 (75.5) 14.2 (76.3) 24.7 (77.9) 27.7 (711.2)
5.7 (73.7) 5.3 (73.2) 11.0 (78.0) 13.6 (712.2)
18.6 (712.3) 16.4 (78.3) 35.2 (720.7) 27.6 (713.8)
13.5 (77.9) 13.6 (77.6) 23.6 (712.5) 21.3 (79.1)
6.4 (74.1) 6.9 (73.4) 17.6 (710.7) 15.9 (79.5)
3.8 (72.7) 3.8 (72.7) 8.5 (76.6) 10.9 (713.1)
25.6 (712.7) 22.5 (713.1) 41.8 (716.0) 36.6 (721.1)
25.7 (715.1) 25.8 (718.7) 40.6 (722.1) 39.1 (724.8)
8.5 (76.4) 8.1 (74.6) 20.6 (713.9) 20.3 (710.7)
3.9 (71.7) 3.6 (72.0) 8.0 (75.1) 10.2 (710.0)
26.0 (713.5) 22.8 (713.8) 42.2 (715.6) 41.7 (718.2)
25.6 (710.7) 23.5 (712.1) 36.7 (715.3) 35.7 (715.4)
7.1 (72.7) 7.3 (72.6) 17.3 (78.7) 16.4 (75.7)
# 2002 Elsevier Science Ltd. All rights reserved.
Table 2 Mean (7 Standard Deviation) for the electromyographic activity of upper trapezius (UT), middle trapezius (MT), lower trapezius (LT), and serratus anterior (SA), expressed as percentage of Maximal Voluntary Contraction during dynamic forward flexion movements in a tape and no-tape condition, with and without external resistance, analysed for four periods of movement (period 1: concentric from 01 to 901 of abduction, period 2: concentric from 901 to 1801 of abduction, period 3: eccentric from 1801 to 901 of abduction, period 4: eccentric from 901 to 01 of abduction) Upper trapezius
No resistance, no tape No resistance, tape Resistance, no tape Resistance, tape
Middle trapezius
Lower trapezius
Serratus anterior
P1
P2
P3
P4
P1
P2
P3
P4
P1
P2
P3
P4
P1
P2
P3
P4
11.2 (76.1) 10.5 (76.0) 18.2 (78.1) 15.6 (76.8)
26.7 (713.4) 25.4 (712.7) 42.5 (714.3) 44.1 (716.7)
21.0 (79.2) 22.2 (712.9) 29.3 (711.8) 30.6 (712.2)
10.2 (74.4) 12.2 (77.0) 20.6 (79.2) 23.3 (711.4)
2.9 (72.3) 2.3 (71.8) 5.7 (74.3) 5.4 (74.5)
8.5 (77.1) 5.7 (74.0) 17.4 (712.2) 16.2 (711.6)
6.3 (74.9) 5.2 (73.2) 10.4 (76.9) 10.2 (78.0)
2.8 (72.1) 2.9 (72.3) 8.5 (76.4) 8.4 (76.7)
4.9 (72.8) 4.8 (72.7) 11.4 (79.5) 10.8 (76.8)
25.7 (712.8) 21.8 (712.9) 38.1 (715.8) 37.5 (720.8)
29.0 (726.3) 23.3 (717.6) 33.6 (726.4) 26.9 (718.5)
8.7 (78.1) 9.7 (78.7) 22.8 (715.5) 25.9 (718.2)
5.5 (72.9) 5.2 (73.3) 10.7 (78.6) 8.8 (75.6)
27.8 (712.3) 25.8 (710.7) 43.8 (716.9) 42.1 (716.4)
26.0 (711.1) 26.4 (714.4) 35.8 (717.2) 36.1 (714.3)
7.3 (73.9) 7.9 (73.8) 19.6 (711.9) 19.7 (78.5)
158 Manual Therapy
Manual Therapy (2002) 7(3), 154–162
Table 1 Mean (7 Standard Deviation) for the electromyographic activity of upper trapezius (UT), middle trapezius (MT), lower trapezius (LT), and serratus anterior (SA), expressed as percentage of Maximal Voluntary Contraction during dynamic abduction movements in a tape and no-tape condition, with and without external resistance, analysed for four periods of movement (period 1: concentric from 01 to 901 of abduction, period 2: concentric from 901 to 1801 of abduction, period 3: eccentric from 1801 to 901 of abduction, period 4: eccentric from 901 to 01 of abduction)
Taping and electromyographic muscle activity in shoulders 159
results indicated that in non-injured shoulders, the upper trapezius was activated prior to the movement, whereas the lower trapezius was not recruited until after the start of the shoulder movement. However, in a recent study, we examined muscle latency times of the different trapezius parts in response to a sudden unexpected arm movement (Cools et al. 2001). Our results showed no significant differences among the trapezius parts in relation to deltoid onset, thus suggesting that the trapezius reacted as a unit in response to a sudden unexpected arm movement (Cools et al. 2001). Although the trapezius muscle is often considered a major stabilizing muscle for the scapula (Johnson et al. 1994; Kibler 1998; Cools et al. 2001), other scapular muscles also contribute to the stability and movement quality of the scapula (Pink & Tibone 2000; Sahrmann 2002). Impaired control of the scapula by the serratus anterior muscle is common in patients with shoulder problems (Pink & Tibone 2000). The levator scapulae and rhomboid muscles are both synergists and antagonists of the trapezius muscle. Their function is to adduct and internally rotate the scapula. Shortness of these muscles may restrict upward rotation of the acromial region, necessary for normal shoulder function (Sahrmann 2002). Scapulohumeral muscles such as latissimus dorsi and pectoralis major also contribute to shoulder function. These muscles essentially bypass the scapula and are attached directly to the humerus, and can contribute to disruption of scapulohumeral rhythm (Sahrmann 2002). Summarizing, it is clear that there are many diverse roles the scapula must play to achieve appropriate shoulder function. These roles are interrelated and depend on the quality of muscle activity in the scapular muscles. Therefore, restoration of normal scapular muscle activity is one of the priorities in the early phase of rehabilitation of the athlete with functional shoulder instability. The purpose of our study was to determine if EMG activity in the scapular muscles was influenced by the application of tape over the muscle belly of the upper trapezius and parallel to the direction of the lower trapezius muscle. Based on previous investigations and clinical assumptions (Morin et al. 1997; McConnell 1999), we hypothesized that with tape the upper trapezius activity would decrease, and the lower trapezius activity would increase. In addition, we assumed that the taping would change the overall recruitment pattern of all scapular rotators, and therefore hypothesized changes in muscle activity of the serratus anterior and middle trapezius. Confirming this hypothesis would be clinically relevant, since scapulothoracic dysfunction is often seen in patients with shoulder problems or cervicobrachial pathologies. In this muscular imbalance, an overactivity of the upper trapezius part is # 2002 Elsevier Science Ltd. All rights reserved.
assumed (Pink 1991; Kelley 1995). The purpose of this tape was to inhibit muscle activity in the upper trapezius part, and to enhance muscle activity in the lower trapezius, thus correcting muscle activity around the scapula. In contrast to the expectations, the results of our investigation revealed no significant changes in EMG activity in the scapular muscles based on the application of tape. Morin et al. (1997) examined the influence of taping on upper and middle trapezius muscle activity during an isometric contraction in the shoulder. Contrary to the results of our study, he found a significant decrease in muscle activity in the upper trapezius muscle with tape application, and an increase in EMG activity of the middle trapezius part. However, looking at the results of both studies, it must be mentioned that in the study of Morin et al. (1997) EMG measurements were performed during isometric muscle contractions, which usually give a more stable EMG signal than dynamic contractions. The dynamic character of the movements performed in our study might give a less steady EMG signal. However, in view of the nature of instability problems and related injuries, dynamic movements over a large range of motions are more functional, and hence more clinically relevant than isometric contractions. In addition, in Morin’s investigation, the serratus anterior and lower fibres of the trapezius, known to play an important role in the scapulothoracic stability and movement, were not included. Two issues regarding our methods should be discussed: the use of surface electrodes to evaluate muscle activity and the use of maximal voluntary contraction as a normalization reference. The current state of surface electromyography is enigmatic. Although it provides many important and useful applications, it has many limitations that must be considered (De Luca 1997). A major problem is the issue of the cross-talk when using surface electrode in the shoulder region. However, in view of the nature of our investigation, in which the same muscle was examined during the same movement under different circumstances, possible cross-talk remained unchanged over the conditions, and therefore probably did not influence our results. Moreover, investigating large muscle groups such as the trapezius muscle, surface electrodes do give a more global evaluation of muscle activity than fine wire electrodes, which measure a rather small selection of muscle fibres. In addition, cross-talk is not likely in our setting since Winter et al. (1994) estimated that 90% of a surface EMG signal has its origin within 12-mm distance from an electrode pair. According to Jensen and Westgaard (1997), the depth of the supraspinatus and levator scapulae muscles suggests that cross-talk contributes a relative small fraction to the total EMG signal using surface electrodes on the upper trapezius muscle. Manual Therapy (2002) 7(3), 154–162
160 Manual Therapy
Although normalization of EMG signal to MVC values is common in EMG studies, its reproducibility and stability is often questioned (Yang & Winter 1983; Jensen et al. 1993; Aaras et al. 1996; Araujo et al. 2000). Some authors state that MVC is an unreliable measurement (Yang & Winter 1983; Araujo et al. 2000), while others concluded that under certain conditions, in which methodological errors influencing the recorded EMG signal from the muscle are kept to a minimum, normalization to MVC values gives reproducible results (Aaras et al. 1996; Danneels et al. 2001a,b). In our investigation, we used guidelines for EMG recording during maximal voluntary contraction proposed by De Luca (1997). Concluding on the basis of our data that taping has no effect on the scapulothoracic muscle activity would be premature. Possibly, taping may affect other parameters of neuromuscular control, such as the muscle reaction times. In recent literature, timing of muscle activity is often mentioned in a neuromuscular context. Lohrer et al. (1999) investigated the neuromuscular properties and functional aspects of taped ankles. He found taping caused changes in muscle latency times, in addition to mechanical restriction of movement. This was interpreted as a proprioceptively activated effect of tape. In addition, the influence of this tape on the biomechanical behaviour of the scapular position was not considered in this study. We must take into account that the use of healthy subjects is a limitation to our study, and further research should emphasize muscle recruitment patterns in patients with abnormal scapular kinematics. Other proprioceptive influences, such as cutaneous stimulation due to tape application, enhanced awareness of shoulder girdle and upper trunk position, and subjective parameters of comfort after tape application, may possibly explain a positive effect of the tape on functional shoulder performance.
CONCLUSIONS Tape is often used in functional rehabilitation of the shoulder patient. Although various taping techniques are used in clinical practice, description of these application methods and clinical studies evaluating the effects of tape are scarce. The purpose of our study was to investigate the effect of tape application over the trapezius muscle on the amount of electromyographic muscle activity in the scapular muscles in healthy, pain-free shoulders. We hypothesized that application of this particular tape would have a proprioceptive effect on muscle activation around the scapula, resulting in a change in intensity of muscle activity in the scapular muscles. We found no significant differences in muscle activity Manual Therapy (2002) 7(3), 154–162
in the trapezius and serratus anterior muscle, based on the application of tape. This scapular technique apparently does not affect muscle function in normal pain-free shoulders. The question arises if the intensity of EMG activity, is a representative parameter for proprioceptive qualities of a muscle. Further research is necessary to measure different aspects of neuromuscular control, in order to determine proprioceptive changes after the application of tape. Although we were unable to reveal significant changes in muscle activity with the application of this tape, the use of the taping techniques in the clinical practice often results in enhanced subjective functional scapular stability. Future research is also needed to determine the neuromuscular mechanism of these functional improvements in patients with scapular instability. Acknowledgements The authors would like to thank Ms Sara Vandevelde and Ms Christel Vangestel for their assistance in collecting the data.
References Aaras A, Veierod MB, Larsen S, Ostergren R, Ro O 1996 Reproducibility and stability of normalized EMG measurements on musculus trapezius. Ergonomics 39(2): 171–185 Anderson DL, Sanderson DJ, Hennig EM 1995 The role of external non-rigid ankle bracing in limiting ankle inversion. Clinical Journal of Sports Medicine 5: 18–24 Anderson K, Woitys EM, Loubert PV, Miller RE 1992 A biomechanical evaluation of taping and bracing in reducing knee joint translation and rotation. The American Journal of Sports Medicine 20(4): 416–421 Araujo RC, Duarte M, Amadio AC 2000 On the inter- and intrasubjects variability of the electromyographic signal in isometric contractions. Electromyography and Clinical Neurophysiology 40(4): 225–229 Arrayo JS, Hershon SJ, Bigliani LU 1997 Special considerations in the athletic throwing shoulder. Orthopedic Clinics of North America 28(1): 69–78 Basmajian JV, De Luca CJ 1985 Muscles Alive: Their Functions Revealed by Electromyography, 5th edn. Williams and Wilkins, Baltimore Bennell KL, Goldie PA 1994 The differential effects of external ankle support on postural control. Journal of Orthopedic and Sports Physical Therapy 20(6): 287–295 Blevins FT 1997 Rotator cuff pathology in athletes. Sports Medicine 24(3): 205–220 Bockrath K, Wooden C, Worrell T, Ingersoll CD, Farr J 1993 Effects of patella taping on patella position and perceived pain. Medicine and Science in Sports and Exercise 25(9): 989–992 Cools AM, Witvrouw EE, Declercq GA, Danneels LA, Willems TM, Cambier DC, Voight ML 2002 Scapular muscle recruitment pattern: electromyographic response of the trapezius muscle to sudden arm movement before and after a fatiguing exercise. J Orthop Sports Phys Ther 32(5): 221–229 Danneels LA, Cagnie BJ, Cools AM, Vanderstraeten GG, Cambier DC, Witvrouw EE, De Cuyper HJ 2001a Intra-operator and inter-operator reliability of surface electromyography in the clinical evaluation of back muscles. Manual Therapy 6(3): 145–153 Danneels LA, Vanderstraeten GG, Cambier DC, Witvrouw EE, Stevens VK, De Cuyper HJ 2001b A functional subdivision of hip, abdominal and back muscles during asymmetric lifting. Spine 26(6): E114–E121 # 2002 Elsevier Science Ltd. All rights reserved.
Taping and electromyographic muscle activity in shoulders 161 Davies GL, Dockoff-Hoffman S 1993 Neuromuscular testing and rehabilitation of the shoulder complex. Journal of Orthopedic Sports Physical therapy 18(2): 210–219 De Luca CJ 1997 The use of surface electromyography in biomechanics. Journal of Applied Biomechanics 13: 135–163 Engstro¨m BK, Renstro¨m PA 1998 How can injuries be prevented in the world cup soccer athlete? Clinics in Sports Medicine 17(4): 755–768 Feuerbach JW, Grabiner MD, Koh TJ, Weiker GG 1994 Effect of an ankle orthosis and ankle ligament anaesthesia on ankle joint proprioception. The American Journal of Sports Medicine 22(2): 223–261 Gilleard W, McConnell J, Parsons D 1998 The effect of patellar taping on the onset of vastus medialis obliquus and vastus lateralis muscle activity in persons with patellofemoral pain. Physical Therapy 78(1): 25–31 Glousman R, Jobe F, Tibone J, Moynes D, Antonelli D, Perry J 1988 Dynamic electromyographic analysis of the throwing shoulder with glenohumeral instability. The Journal of Bone and Joint Surgery 70A(2): 220–226 Greene TA, Wight CR 1990 A comparative support evaluation of three ankle orthoses before, during and after exercise. Journal of Orthopedic and Sports Physical Therapy 11: 453–466 Gross MT, Batten AL, Lamm AL 1994 Comparison of Donjoy ankle ligament protector and subtalar sling ankle taping in restricting foot and ankle motion before and after exercise. Journal of Orthopedic and Sports Physical Therapy 19(1): 33–41 Hancock RE, Hawkins RJ 1996 Applications of electromyography in the throwing shoulder. Clinical Orthopaedics and Related Research 330: 84–97. Hall CM 1999 The shoulder girdle. In: Hall CM, Brody LT (eds) Therapeutic Exercise: Moving Toward Function. Lippincott Williams and Wilkins, Philadelphia Heit EJ, Lephart SM, Rozzi SL 1996 The effect of ankle bracing and taping on joint position sense in the stable ankle. Journal of Sports Rehabilitation 5: 206–213 Host HH 1995 Scapular taping in the treatment of anterior shoulder impingement. Physical Therapy 75(9): 803–812 Jensen C, Vasseljen O, Westgaard RH 1993 the influence of electrode position on bipolar surface electromyogram recordings of the upper trapezius muscle. European Journal of Applied Physiology 67: 266–273 Jensen C, Westgaard R 1997 Functional subdivision of the upper trapezius muscle during low-level activation. European Journal of Applied Physiology 76: 335–339 Johnson G, Bogduk N, Nowitzke A, House D 1994 Anatomy and actions of the trapezius muscle. Clinical Biomechanics 9: 44–50 Kamkar A, Irrgang JI, Whitney SL 1993 Non-operative management of secondary impingement syndrome. Journal of Orthopedic and Sports Physical Therapy 17(5): 212–224 Karlsson J, Andreasson GO 1992 The effect of external ankle support in chronic lateral ankle joint instability: An electromyographic study. The American Journal of Sports Medicine 20(3): 257–261 Kelley MJ 1995 Anatomic and biomechanical rationale for rehabilitation of the athlete’s shoulder. Journal of Sports Rehabilitation 4: 122–154 Kelly BT, Kadrmas WR, Speer KP 1996 The manual muscle examination for rotator cuff strength: An electromyographic investigation. Journal of Orthopedic and Sports Physical Therapy 24(5): 581–588 Kendall FP, Kendall EK 1983 Muscles, Testing and Function. Williams and Wilkins, Baltimore Kibler WB 1998 The role of the scapula in athletic shoulder function. The American Journal of Sports Medicine 26(2): 325–337 Konradson L, Voight M, Hojsgaard C 1997 Ankle inversion injuries: the role of the dynamic defence mechanism. The American Journal of Sports Medicine 25(1): 54–58 Kowall MG, Kolk G, Nuber GW, Cassisi JE, Stern SH 1996 Patellar taping in the treatment of patellofemoral pain: A prospective randomized study. The American Journal of Sports Medicine 24(1): 61–65 Larsen B, Andreansen E, Urfer A, Mickeslon MR, Newhouse KE 1995 Patellar taping: A radiographic examination of the medial # 2002 Elsevier Science Ltd. All rights reserved.
glide technique. The American Journal of Sports Medicine 23(4): 465–470 Lindman R, Eriksson A, Thornell L-E 1990 Fiber type composition of the human male trapezius muscle: Enzymehistochemical characteristics. American Journal of Anatomy 189: 236–244. Lindman R, Eriksson A, Thornell L-E 1991 Fiber type composition of the human female trapezius muscle: Enzymehistochemical characteristics. American Journal of Anatomy 190: 385–392. Lohrer H, Alt W, Gollhofer A 1999 Neuromuscular properties and functional aspects of taped ankles. The American Journal of Sports Medicine 27(1): 69–75 Ludewig PM, Cook TM, Nawocsenski DA 1996 Threedimensional scapular orientation and muscle activity at selected positions of humeral elevation. Journal of Orthopedic and Sports Physical Therapy 24(2): 57–65 Lukasiewicz AC, McClure P, Michiner L, Pratt N, Sennett B 1999 Comparison of three dimensional scapular position and orientation between subjects with and without shoulder impingement. Journal of Orthopedic and Sports Physical Therapy 29(10): 574–586 McCann PD, Wootten ME, Kadaba MP, Bigliani LU 1993 A kinematic and electromyographic study of shoulder rehabilitation exercises. Clinical Orthopedics and Related Researches 288: 179–188 McConnell J. The Mc Connell approach to the problem shoulder. Taping: Inhibition of the upper trapezius muscle. 1999 Course Notes, p 34. McCaw ST, Cerullo JF 1999 Prophylactic ankle stabilizers affect ankle joint kinematics during drop landings. Medicine and Science in Sports and Exercise 31(5): 702–707 McMahon PJ, Jobe FW, Pink MM, Brault JR, Perry J 1996 Comparative electromyographic analysis of shoulder muscles during planar motions: Anterior glenohumeral instability versus normal. Journal of Shoulder and Elbow Surgery 5: 118–123 McQuade KJ, Dawson J, Smidt GL 1998 Scapulothoracic muscle fatigue associated with alterations in scapulohumeral rhythm kinematics during maximum resistive shoulder elevation. Journal of Orthopedic and Sports Physical Therapy 28(2): 74–80 Morin GE, Tiberio D, Austin G 1997 The effect of upper trapezius taping on electromyographic activity in the upper and middle trapezius region. Journal of Sports Rehabilitation 6: 309–319 Mottram SL 1997 Dynamic stability of the scapula. Manual Therapy 2(3): 123–131 Pink M, Perry J, Browne A, Scovacco ML, Kerrigan J 1991 The normal shoulder during free style swimming: An electromyographic and cinematographic analysis of twelve muscles. The American Journal of Sports Medicine 19: 569–576 Pink MM, Tibone JE 2000 The painful shoulder in the swimming athlete. Orthopedic Clinics of North America 31(2): 247–261 Robbins S, Waked E 1998 Factors associated with ankle injuries: Preventive measures. Sports Medicine 25(1): 63–72 Rupp S, Berninger K, Hopf T 1995 Shoulder problems in high level swimmersFimpingement, anterior instability, muscular imbalance? International Journal of Sports Medicine 16: 557–562 Sahrmann SA 2002 Diagnosis and treatment of Movement Impairment Syndromes, 1st edn., chapter 5, pp 193–245, Mosby, St.Louis Schmitt L, Snyder-Mackler L 1999 Role of scapular stabilizers in etiology and treatment of impingement syndrome. Journal of Orthopedic and Sports Physical Therapy 29(1): 31–38 Shamus JL, Shamus EC 1997 A taping technique for the treatment of acromioclavicular joint sprains: A case study. Journal of Orthopedic and Sports Physical Therapy 25(6): 390–394 Somes S, Worrell TW, Corey B, Ingersol CD 1997 Effects of patellar taping on patellar position in the open and closed kinetic chain: A preliminary study. Journal of Sports Rehabilitation 6: 299–308 Wadsworth DJ, Bullock-Saxton JE 1997 Recruitment patterns of the scapular rotator muscles in freestyle swimmers with subacromial impingement. International Journal of Sports Medicine 18: 618–624 Manual Therapy (2002) 7(3), 154–162
162 Manual Therapy Weiser WM, Lee TQ, McMaster WC 1999 Effects of simulated scapular protraction on anterior glenohumeral stability. The American Journal of Sports Medicine 27(6): 801–805 Wilk KE, Arrigo C 1993 Current concepts in the rehabilitation of the athletic shoulder. Journal of Orthopedic and Sports Physical Therapy 18(1): 365–378 Wilkerson GB 1991 Comparative biomechanical effects of the standard method of ankle taping and a taping method designed
Manual Therapy (2002) 7(3), 154–162
to enhance subtalar stability. The American Journal of Sports Medicine 19(6): 588–595 Winter DA, Fuglevand AJ, Archer SE 1994 Crosstalk in surface electromyography: Theoretical and practical estimates. Journal of Electromyography and Kinesiology 4: 15–26 Yang JF, Winter DA 1983 Electromyography reliability in maximal and submaximal isometric contractions. Archives of Physical Medicine and Rehabilitation 64: 417–420
# 2002 Elsevier Science Ltd. All rights reserved.
Original article
Does taping influence electromyographic muscle activity in the scapular rotators in healthy shoulders? A. M. Cools, E. E. Witvrouw, L. A. Danneels, D. C. Cambier Department of Rehabilitation Sciences and Physiotherapy & Postgraduate Education in Manual Therapy, Faculty of Medicine and Health Sciences, University Hospital, Ghent, Belgium
SUMMARY. Although taping techniques are commonly used in addition to exercise programmes in the rehabilitation of shoulder instability and secondary subacromial or internal impingement, few studies exist on the effect of taping on the muscle activity of the scapular rotators. The purpose of our study was to examine the influence of one particular tape on muscular activity in scapular muscles. Twenty healthy shoulders were examined with surface EMG recordings on the three parts of trapezius and serratus anterior muscle during dynamic full range of motion abduction and forward flexion. The movement direction, and tape and no-tape conditions were randomized. The statistical analyses with ANOVA repeated Measures (GLM model) showed significant differences among the means between the four muscles (Po0.05), two movement directions (Po0.05), applied resistance (Po0.01), and movement period (Po0.01). However, no significant difference was observed based on the application of tape. The results of our investigation revealed no significant influence of tape application on EMG activity in the scapular muscles in healthy subjects. Future research will be necessary to examine other parameters of neuromuscular control in order to determine possible proprioceptive changes in muscle recruitment with tape application. r 2002 Elsevier Science Ltd. All rights reserved.
Most authors agree that the effect of tape can only partially be explained by increased mechanical stability (Wilkerson 1991; Bockrath et al. 1993; Bennell & Goldie 1994, Larsen et al. 1995; Kowall et al. 1996; Somes et al. 1997; Gilleard et al. 1998; Lohrer et al. 1999; McCaw & Cerullo 1999). It is suggested, however, that taping may have some proprioceptive influences. Therefore, if taping techniques do give joint protection, it is now thought that they act by improving proprioception rather than by restricting movement (Karllson & Andreasson 1992; Heit et al. 1996; Robbins & Waked 1998). The effectiveness of various taping techniques was studied extensively in the knee (Anderson et al. 1992; Bockrath et al. 1993; Larsen et al. 1995; Kowall et al. 1996; Gilleard et al. 1998), and the ankle (Wilkerson 1991; Karlsson & Andreasson 1992; Lohrer et al. 1999; McCaw & Cerullo 1999). Although the influence of taping on neuromuscular function is often suggested, the underlying mechanism is still unclear. Some authors found changes in the onset of muscle activity in the knee with tape (Karlsson & Andreasson 1992; Gilleard et al. 1998). They assumed that changes in latency times might be the result of cutaneous stimulation effected by the
INTRODUCTION The application of taping is widely used among athletes both in the rehabilitation and in the prevention of sports injuries (Engstro¨m & Renstro¨m 1998; Robbins & Waked 1998). The basic rationale for taping is to provide protection and support for a joint while permitting optimal functional movement. It is assumed that external support increases joint stability by reinforcing the ligaments and restricting motions. However, various authors mention that the support function of taping is lost within a relatively short time after application (Greene & Wight 1990; Gross et al. 1994; Lohrer et al. 1999). Received: 28 January 2002 Revised: 13 May 2002 Accepted: 5 June 2002 Ann M. Cools, PT, candidate for a doctoral degree, Erik E. Witvrouw, PT, PhD, Lieven A. Danneels, PT, PhD, Dirk C. Cambier, PT, PhD, Director, Department of Rehabilitation Sciences and Physiotherapy, Ghent University, Ghent, Belgium. Correspondence to: AC, Department of Rehabilitation Sciences and Physiotherapy & Postgraduate Education in Manual Therapy, University Hospital Ghent, De Pintelaan 185, 1B3, B9000 Ghent, Belgium. Tel.: +32/240 26 32; Fax: +32/240 38 11 E-mail: [email protected] 154
Taping and electromyographic muscle activity in shoulders 155
tape. This theory supposes that traction on the skin or the pressure of the tape provides cutaneous sensory cues, thus providing additional proprioceptive input to the central nervous system. Recently, various taping techniques of the scapula have been introduced into the conservative management of the shoulder girdle (Host 1995; Mottram 1997; Hall 1999; Schmitt & Snyder-Mackler 1999). The purpose of these techniques is to normalize the scapulohumeral rhythm by influencing the scapular muscle activity and correcting abnormal scapular position. Scapulothoracic dysfunction is often seen in patients with shoulder problems or cervicobrachial pathologies (Glousman et al. 1988; Kamkar et al. 1993; Host 1995; Rupp et al. 1995; McMahon et al. 1996; Arrayo et al. 1997; Blevins 1997; Mottram 1997; Wadsworth & Bullock-Saxton 1997; Kibler 1998; Lukasiewicz et al. 1999; Schmitt & SnyderMackler 1999; Pink & Tibone 2000; Sahrmann 2002). A current belief is that weakness of the scapular musculature will affect normal scapular positioning. It has been suggested that if excessive motion of the scapula occurs, this may place increased stress on the glenohumeral capsular structures and lead to increased glenohumeral instability. Malpositioning of the scapula for any given arm configuration may also influence the instantaneous centre of shoulder rotation, which can significantly alter moments of force generation about the shoulder (McQuade et al. 1998). Scapulothoracic muscle weakness, and hence the lack of scapular stability, has also been identified as a cause of secondary subacromial impingement syndrome (Kamkar et al. 1998; Kibler 1998; Schmitt & Snyder-Mackler 1999). Although much of the conservative management of patients with shoulder impingement is predicated upon correction of faulty and aberrant scapular motion patterns, quantitative evidence documenting specific patterns of abnormal scapular motions in this patient group is still quite limited (Lukasiewicz et al. 1999). Some authors (Pink et al. 1991; Kelley 1995) state that muscular imbalance in throwing athletes, frequently consist of overcompensation of the scapular elevators. This increased upper trapezius activity can lead to hypertrophy and constant tension overload in these muscle fibres. Others (Kamkar et al. 1993; Host 1995; Kibler 1998) suggest that insufficient upward rotation of the scapula, causing a lack of appropriate acromial elevation during overhead shoulder motion such as throwing, may contribute to secondary subacromial impingement. A relative decrease in the subacromial space due to functional scapulothoracic instability would be the underlying mechanism. According to Blevins (1997), limited upward rotation of the scapula is a contributing factor to internal or superior glenoid impingement. The pinching of the posterior–superior rotator cuff tendons between the humerus and the posterior–superior glenoid rim may # 2002 Elsevier Science Ltd. All rights reserved.
be caused by a lack of scapular elevation and retraction in the cocking position. Although taping techniques are commonly used in addition to exercise programmes in the rehabilitation of shoulder instability and secondary subacromial or internal impingement, few studies exist on the effect of taping on the muscle activity of the scapular rotators. Therefore, the purpose of this study was to examine the influence of tape application on muscular activity in scapular muscles (three trapezius parts and serratus anterior) during a dynamic abduction and forward flexion movement.
MATERIALS AND METHODS Subjects Twenty healthy male subjects volunteered to participate in this study. Exclusion criteria were current or past history of shoulder pain, shoulder instability or chronic cervicobrachial pain symptoms, and participation in overhead sports. The mean age of the group was 22.15 years (range 20–25), mean body weight 71.35 kg (range 61–90), and mean height 180.74 cm (range 169–188). Fifteen subjects were right handed, five were left handed. The dominant shoulder was tested in all subjects. All subjects signed an informed consent before participating in the investigation. The study was approved by the Ethical Committee of Ghent University. Materials Prior to electrode application, the skin was prepared with alcohol to reduce skin impedance (typically o10 kO). Bipolar surface electrodes (Blue Sensors – Medicotest, Denmark) were placed with a 1 cm interelectrode distance over the upper, middle and lower portions of the trapezius muscle and the lower portion of the serratus anterior. All electrodes were placed according to the protocol described by Basmajian and De Luca (1985), although the electrode position of the upper trapezius was slightly medialized, thus allowing proper tape application on the muscle belly (Fig. 1). Electrodes for the upper trapezius were placed midway between the spinous process of the seventh cervical vertebra and the posterior tip of the acromion process along the line of the trapezius. The middle trapezius electrode was placed midway on a horizontal line between the root of the spine of the scapula and the thoracic spine. The lower trapezius electrode was placed obliquely upward and laterally along a line between the intersection of the spine of the scapula with the vertebral border of the scapula and the seventh thoracic spinous process. The serratus anterior electrode was placed midway between the lateral, Manual Therapy (2002) 7(3), 154–162
156 Manual Therapy
Fig. 2 Fig. 1
inferior border of the scapula and the insertion of the muscle on the anterio-lateral side of the thorax. A reference electrode was placed over the clavicle. Each set of bipolar recording electrodes on each of the four muscles was connected to a Noraxon Myosystem 2000 electromyographic receiver (Noraxon USA, Inc., Scottsdale, AZ). The sampling rate was 1000 Hz. All raw myo-electric signals were preamplified (overall gain = 1000, common rate rejection ratio 115 dB, signal-to-noise ratio o1 mV RMS baseline noise, filtered to produce a bandwidth of 10–1000 Hz). A strip of Fixomull stretch (Beiersdorfs) was applied over the muscle belly of the upper trapezius, starting anterior just proximal to the clavicle. The tape was firmly pulled over the belly of the upper trapezius, meanwhile giving a skin traction on the soft tissue towards the cervical spine. On the posterior side of the trunk, the tape was attached towards the thoracic spine, following the muscle fibres of the lower trapezius. The same procedure was repeated with a leukotape P strip (Beiersdorfs) (McConnell 1999). All the taping applications were performed by the same researcher, who is experienced in the procedure (Fig. 2). Testing procedure The testing session started with a warm-up procedure, consisting of shoulder movements in all directions, push-up-exercises against the wall and stretching exercises for the rotator cuff and scapular muscles. Then verification of EMG signal quality was completed for each muscle by having the subject perform isometric contractions in manual muscle test positions specific to each muscle of interest (Kendall & Kendall 1983). Subjects performed three 5-s maximum voluntary isometric muscle contractions against manual resistance by the principal investigator. A 5-s pause occurred between muscle contracManual Therapy (2002) 7(3), 154–162
tions (Hancock & Hawkins 1996, De Luca 1997). As a normalization reference, EMG data were collected during maximal voluntary contraction (MVC) for each muscle. After signal filtering with a low-pass filter (single pass, Butterworth, 6 Hz low-pass filter of the 6th order) and visual inspection for artefacts, the peak average EMG value over a window of 1 s was calculated for each trial. Further calculations were performed with the mean of the repeated trials as a normalization value (100%) (Danneels et al. 2001). To avoid alterations in muscle activity of the upper trapezius caused by head position or movement, the subjects were instructed to look in front of them while testing. Two movements were performed during the test: abduction in the frontal plane, and forward flexion in the sagittal plane. Each movement was performed over the whole range of motion in a rhythm of 4 s:2 s of concentric contraction and upward movement, and 2 s of eccentric contraction and downward movement, with 4 s of rest between trials. The rhythm was set by a metronome and controlled by the examiner’s counting. Prior to starting collecting data, subjects were allowed five practice trials to ensure they completed the arm movement in a 4 s rhythm, as set by the metronome. Following the practice trials, the subject completed three trials of each movement. The second movement was used for further analysis. Each movement was performed with and without an external resistance, and in a tape and a no-tape condition. The weight resistance was set at 2 kg for a body weight between 50 and 60 kg, 2.5 kg for a body weight between 70 and 80 kg, and 3 kg if the person weighed more than 80 kg. The test conditions tape/ no-tape and abduction/forward flexion were randomized. Signal processing All raw EMG signals were analogue/digital (A/D) converted (12-bit resolution) at 1000 Hz. Signals then # 2002 Elsevier Science Ltd. All rights reserved.
Taping and electromyographic muscle activity in shoulders 157
were digitally full-wave rectified and low-pass filtered (single pass, Butterworth, 6 Hz low pass filter of sixth order). Results were normalized to the maximum activity observed during the maximal voluntary trials. After rectifying, filtering and normalization, further analysis was performed on four periods during arm movement, each of 1-s duration. Periods were defined by markers, automatically placed on the EMG signal with every metronome signal. The mean amplitude EMG signal, expressed as a percentage of maximal voluntary contraction, was used to assess the activity of the three trapezius parts and serratus anterior muscle in each condition and each period. Statistical analysis Differences in EMG activity among the several conditions were analysed with an univariate approach to repeated measures analysis of variance (General Linear Model), in which the within-subject factors were: (1) muscle, (2) movement direction (3) resistance, (4) tape, and (5) period. The alpha-level for the ANOVA was set as 0.05. In case of significant differences, paired t-tests with Bonferroni correction were used for post-hoc multiple pairwise comparisons. All statistical analysis was performed with the Statistical Package for Social Sciences (SPSS), version 9.0.
RESULTS The results of the descriptive statistical analyses are summarized in Table 1 for the abduction movement with and without external resistance, and Table 2 for the forward flexion movement, with and without external resistance. The statistical analysis with ANOVA repeated measures General Linear and Model (GLM) showed significant differences in EMG activity based on the factors muscle (Po0.01), movement direction (Po0.01), resistance (Po0.01), and period (Po 0.01), but no significant difference based on the application of tape (P = 0.578). The analysis of interaction effects for the muscle factor revealed significant muscle movement direction interaction effect (Po0.05), and no significant interaction for muscle period (P = 0.126) and muscle resistance (P = 0.720). There was no significant interaction between the tape factor and any other factor in the GLM. The results show that the application of tape has no influence on EMG activity in all conditions, and differences in EMG activity based on all other factors are independent of tape application (no tape other factor interaction). Since the influence of tape on EMG activity for the four muscles was of particular interest, and the ANOVA showed no significant differences based on # 2002 Elsevier Science Ltd. All rights reserved.
the application of tape, further post-hoc analyses on the factor tape were not performed.
DISCUSSION Normal muscle activity of the scapular rotators allows for normal kinematics of the scapular movement. The role of the scapular muscles is to promote glenohumeral stability, to provide a stable basis from which other muscles can operate in an optimal length–tension relationship, and to elevate the acromion during arm elevation in order to prevent impingement (Wilk & Arrigo 1993; Mottram 1997). In addition, the scapula plays an important role of being a link in the kinetic chain of proximal to distal sequencing of velocity, energy and forces in many shoulder activities such as throwing (Kibler 1998). Anatomic and histochemical studies regarding trapezius muscle composition found some functional subdivisions within the trapezius muscle. Lindman et al. (1990, 1991) found that the ascending portion of the trapezius muscle (arising from the spinous processes and interspinous ligaments of approximately the T4–T12 vertebrae, and attaching in the region of the tubercle at the medial end of the spine of the scapula) had a predominance of type I fibres, whereas the most superior parts of pars descendens (from the medial third of the superior nuchal line and the ligamentum nuchae to the posterior border of the lateral third of the clavicle) had a higher frequency of type II fibres. These differences in fibre type might reflect different functional demands on the trapezius muscle parts in various head, neck, and shoulder movements. The author concluded that the lower trapezius seems best suited for postural and stabilizing functions in the shoulder and arm movements, whereas the upper trapezius seems best suited for phasic activities. Similar conclusions can be drawn from a dissection study revealing the fascicular anatomy of the trapezius (Johnson et al. 1994). Based on the orientation of the fibres of the lower trapezius, it was suggested that the role of the lower part of the trapezius is more consistent with maintaining horizontal and vertical equilibrium of the scapula rather than generating net torque. In addition, Johnson et al. (1994) hypothesized that the thoracic fibres of the trapezius muscle do not appreciably change length throughout the entire range of upward rotation of the scapula. Hence, the contribution of the lower trapezius to net torque about the axis of rotation of the scapula was thought to be limited. The upper fibres of trapezius exert an upward rotation moment about this axis, complementing that of the serratus anterior. Wadsworth and Bullock-Saxton (1997) examined the temporal recruitment patterns of the scapular rotator muscles during controlled voluntary abduction in the scapular plane. Their Manual Therapy (2002) 7(3), 154–162
Upper trapezius
No resistance, no tape No resistance, tape Resistance, no tape Resistance, tape
Middle trapezius
Lower trapezius
Serratus anterior
P1
P2
P3
P4
P1
P2
P3
P4
P1
P2
P3
P4
P1
P2
P3
P4
9.8 (74.3) 10.9 (76.4) 19.8 (711.1) 22.3 (711.2)
28.8 (710.5) 29.6 (711.3) 51.7 (716.6) 51.7 (717.9)
21.9 (710.9) 22.7 (78.6) 32.1 (711.7) 34.7 (713.3)
12.2 (75.5) 14.2 (76.3) 24.7 (77.9) 27.7 (711.2)
5.7 (73.7) 5.3 (73.2) 11.0 (78.0) 13.6 (712.2)
18.6 (712.3) 16.4 (78.3) 35.2 (720.7) 27.6 (713.8)
13.5 (77.9) 13.6 (77.6) 23.6 (712.5) 21.3 (79.1)
6.4 (74.1) 6.9 (73.4) 17.6 (710.7) 15.9 (79.5)
3.8 (72.7) 3.8 (72.7) 8.5 (76.6) 10.9 (713.1)
25.6 (712.7) 22.5 (713.1) 41.8 (716.0) 36.6 (721.1)
25.7 (715.1) 25.8 (718.7) 40.6 (722.1) 39.1 (724.8)
8.5 (76.4) 8.1 (74.6) 20.6 (713.9) 20.3 (710.7)
3.9 (71.7) 3.6 (72.0) 8.0 (75.1) 10.2 (710.0)
26.0 (713.5) 22.8 (713.8) 42.2 (715.6) 41.7 (718.2)
25.6 (710.7) 23.5 (712.1) 36.7 (715.3) 35.7 (715.4)
7.1 (72.7) 7.3 (72.6) 17.3 (78.7) 16.4 (75.7)
# 2002 Elsevier Science Ltd. All rights reserved.
Table 2 Mean (7 Standard Deviation) for the electromyographic activity of upper trapezius (UT), middle trapezius (MT), lower trapezius (LT), and serratus anterior (SA), expressed as percentage of Maximal Voluntary Contraction during dynamic forward flexion movements in a tape and no-tape condition, with and without external resistance, analysed for four periods of movement (period 1: concentric from 01 to 901 of abduction, period 2: concentric from 901 to 1801 of abduction, period 3: eccentric from 1801 to 901 of abduction, period 4: eccentric from 901 to 01 of abduction) Upper trapezius
No resistance, no tape No resistance, tape Resistance, no tape Resistance, tape
Middle trapezius
Lower trapezius
Serratus anterior
P1
P2
P3
P4
P1
P2
P3
P4
P1
P2
P3
P4
P1
P2
P3
P4
11.2 (76.1) 10.5 (76.0) 18.2 (78.1) 15.6 (76.8)
26.7 (713.4) 25.4 (712.7) 42.5 (714.3) 44.1 (716.7)
21.0 (79.2) 22.2 (712.9) 29.3 (711.8) 30.6 (712.2)
10.2 (74.4) 12.2 (77.0) 20.6 (79.2) 23.3 (711.4)
2.9 (72.3) 2.3 (71.8) 5.7 (74.3) 5.4 (74.5)
8.5 (77.1) 5.7 (74.0) 17.4 (712.2) 16.2 (711.6)
6.3 (74.9) 5.2 (73.2) 10.4 (76.9) 10.2 (78.0)
2.8 (72.1) 2.9 (72.3) 8.5 (76.4) 8.4 (76.7)
4.9 (72.8) 4.8 (72.7) 11.4 (79.5) 10.8 (76.8)
25.7 (712.8) 21.8 (712.9) 38.1 (715.8) 37.5 (720.8)
29.0 (726.3) 23.3 (717.6) 33.6 (726.4) 26.9 (718.5)
8.7 (78.1) 9.7 (78.7) 22.8 (715.5) 25.9 (718.2)
5.5 (72.9) 5.2 (73.3) 10.7 (78.6) 8.8 (75.6)
27.8 (712.3) 25.8 (710.7) 43.8 (716.9) 42.1 (716.4)
26.0 (711.1) 26.4 (714.4) 35.8 (717.2) 36.1 (714.3)
7.3 (73.9) 7.9 (73.8) 19.6 (711.9) 19.7 (78.5)
158 Manual Therapy
Manual Therapy (2002) 7(3), 154–162
Table 1 Mean (7 Standard Deviation) for the electromyographic activity of upper trapezius (UT), middle trapezius (MT), lower trapezius (LT), and serratus anterior (SA), expressed as percentage of Maximal Voluntary Contraction during dynamic abduction movements in a tape and no-tape condition, with and without external resistance, analysed for four periods of movement (period 1: concentric from 01 to 901 of abduction, period 2: concentric from 901 to 1801 of abduction, period 3: eccentric from 1801 to 901 of abduction, period 4: eccentric from 901 to 01 of abduction)
Taping and electromyographic muscle activity in shoulders 159
results indicated that in non-injured shoulders, the upper trapezius was activated prior to the movement, whereas the lower trapezius was not recruited until after the start of the shoulder movement. However, in a recent study, we examined muscle latency times of the different trapezius parts in response to a sudden unexpected arm movement (Cools et al. 2001). Our results showed no significant differences among the trapezius parts in relation to deltoid onset, thus suggesting that the trapezius reacted as a unit in response to a sudden unexpected arm movement (Cools et al. 2001). Although the trapezius muscle is often considered a major stabilizing muscle for the scapula (Johnson et al. 1994; Kibler 1998; Cools et al. 2001), other scapular muscles also contribute to the stability and movement quality of the scapula (Pink & Tibone 2000; Sahrmann 2002). Impaired control of the scapula by the serratus anterior muscle is common in patients with shoulder problems (Pink & Tibone 2000). The levator scapulae and rhomboid muscles are both synergists and antagonists of the trapezius muscle. Their function is to adduct and internally rotate the scapula. Shortness of these muscles may restrict upward rotation of the acromial region, necessary for normal shoulder function (Sahrmann 2002). Scapulohumeral muscles such as latissimus dorsi and pectoralis major also contribute to shoulder function. These muscles essentially bypass the scapula and are attached directly to the humerus, and can contribute to disruption of scapulohumeral rhythm (Sahrmann 2002). Summarizing, it is clear that there are many diverse roles the scapula must play to achieve appropriate shoulder function. These roles are interrelated and depend on the quality of muscle activity in the scapular muscles. Therefore, restoration of normal scapular muscle activity is one of the priorities in the early phase of rehabilitation of the athlete with functional shoulder instability. The purpose of our study was to determine if EMG activity in the scapular muscles was influenced by the application of tape over the muscle belly of the upper trapezius and parallel to the direction of the lower trapezius muscle. Based on previous investigations and clinical assumptions (Morin et al. 1997; McConnell 1999), we hypothesized that with tape the upper trapezius activity would decrease, and the lower trapezius activity would increase. In addition, we assumed that the taping would change the overall recruitment pattern of all scapular rotators, and therefore hypothesized changes in muscle activity of the serratus anterior and middle trapezius. Confirming this hypothesis would be clinically relevant, since scapulothoracic dysfunction is often seen in patients with shoulder problems or cervicobrachial pathologies. In this muscular imbalance, an overactivity of the upper trapezius part is # 2002 Elsevier Science Ltd. All rights reserved.
assumed (Pink 1991; Kelley 1995). The purpose of this tape was to inhibit muscle activity in the upper trapezius part, and to enhance muscle activity in the lower trapezius, thus correcting muscle activity around the scapula. In contrast to the expectations, the results of our investigation revealed no significant changes in EMG activity in the scapular muscles based on the application of tape. Morin et al. (1997) examined the influence of taping on upper and middle trapezius muscle activity during an isometric contraction in the shoulder. Contrary to the results of our study, he found a significant decrease in muscle activity in the upper trapezius muscle with tape application, and an increase in EMG activity of the middle trapezius part. However, looking at the results of both studies, it must be mentioned that in the study of Morin et al. (1997) EMG measurements were performed during isometric muscle contractions, which usually give a more stable EMG signal than dynamic contractions. The dynamic character of the movements performed in our study might give a less steady EMG signal. However, in view of the nature of instability problems and related injuries, dynamic movements over a large range of motions are more functional, and hence more clinically relevant than isometric contractions. In addition, in Morin’s investigation, the serratus anterior and lower fibres of the trapezius, known to play an important role in the scapulothoracic stability and movement, were not included. Two issues regarding our methods should be discussed: the use of surface electrodes to evaluate muscle activity and the use of maximal voluntary contraction as a normalization reference. The current state of surface electromyography is enigmatic. Although it provides many important and useful applications, it has many limitations that must be considered (De Luca 1997). A major problem is the issue of the cross-talk when using surface electrode in the shoulder region. However, in view of the nature of our investigation, in which the same muscle was examined during the same movement under different circumstances, possible cross-talk remained unchanged over the conditions, and therefore probably did not influence our results. Moreover, investigating large muscle groups such as the trapezius muscle, surface electrodes do give a more global evaluation of muscle activity than fine wire electrodes, which measure a rather small selection of muscle fibres. In addition, cross-talk is not likely in our setting since Winter et al. (1994) estimated that 90% of a surface EMG signal has its origin within 12-mm distance from an electrode pair. According to Jensen and Westgaard (1997), the depth of the supraspinatus and levator scapulae muscles suggests that cross-talk contributes a relative small fraction to the total EMG signal using surface electrodes on the upper trapezius muscle. Manual Therapy (2002) 7(3), 154–162
160 Manual Therapy
Although normalization of EMG signal to MVC values is common in EMG studies, its reproducibility and stability is often questioned (Yang & Winter 1983; Jensen et al. 1993; Aaras et al. 1996; Araujo et al. 2000). Some authors state that MVC is an unreliable measurement (Yang & Winter 1983; Araujo et al. 2000), while others concluded that under certain conditions, in which methodological errors influencing the recorded EMG signal from the muscle are kept to a minimum, normalization to MVC values gives reproducible results (Aaras et al. 1996; Danneels et al. 2001a,b). In our investigation, we used guidelines for EMG recording during maximal voluntary contraction proposed by De Luca (1997). Concluding on the basis of our data that taping has no effect on the scapulothoracic muscle activity would be premature. Possibly, taping may affect other parameters of neuromuscular control, such as the muscle reaction times. In recent literature, timing of muscle activity is often mentioned in a neuromuscular context. Lohrer et al. (1999) investigated the neuromuscular properties and functional aspects of taped ankles. He found taping caused changes in muscle latency times, in addition to mechanical restriction of movement. This was interpreted as a proprioceptively activated effect of tape. In addition, the influence of this tape on the biomechanical behaviour of the scapular position was not considered in this study. We must take into account that the use of healthy subjects is a limitation to our study, and further research should emphasize muscle recruitment patterns in patients with abnormal scapular kinematics. Other proprioceptive influences, such as cutaneous stimulation due to tape application, enhanced awareness of shoulder girdle and upper trunk position, and subjective parameters of comfort after tape application, may possibly explain a positive effect of the tape on functional shoulder performance.
CONCLUSIONS Tape is often used in functional rehabilitation of the shoulder patient. Although various taping techniques are used in clinical practice, description of these application methods and clinical studies evaluating the effects of tape are scarce. The purpose of our study was to investigate the effect of tape application over the trapezius muscle on the amount of electromyographic muscle activity in the scapular muscles in healthy, pain-free shoulders. We hypothesized that application of this particular tape would have a proprioceptive effect on muscle activation around the scapula, resulting in a change in intensity of muscle activity in the scapular muscles. We found no significant differences in muscle activity Manual Therapy (2002) 7(3), 154–162
in the trapezius and serratus anterior muscle, based on the application of tape. This scapular technique apparently does not affect muscle function in normal pain-free shoulders. The question arises if the intensity of EMG activity, is a representative parameter for proprioceptive qualities of a muscle. Further research is necessary to measure different aspects of neuromuscular control, in order to determine proprioceptive changes after the application of tape. Although we were unable to reveal significant changes in muscle activity with the application of this tape, the use of the taping techniques in the clinical practice often results in enhanced subjective functional scapular stability. Future research is also needed to determine the neuromuscular mechanism of these functional improvements in patients with scapular instability. Acknowledgements The authors would like to thank Ms Sara Vandevelde and Ms Christel Vangestel for their assistance in collecting the data.
References Aaras A, Veierod MB, Larsen S, Ostergren R, Ro O 1996 Reproducibility and stability of normalized EMG measurements on musculus trapezius. Ergonomics 39(2): 171–185 Anderson DL, Sanderson DJ, Hennig EM 1995 The role of external non-rigid ankle bracing in limiting ankle inversion. Clinical Journal of Sports Medicine 5: 18–24 Anderson K, Woitys EM, Loubert PV, Miller RE 1992 A biomechanical evaluation of taping and bracing in reducing knee joint translation and rotation. The American Journal of Sports Medicine 20(4): 416–421 Araujo RC, Duarte M, Amadio AC 2000 On the inter- and intrasubjects variability of the electromyographic signal in isometric contractions. Electromyography and Clinical Neurophysiology 40(4): 225–229 Arrayo JS, Hershon SJ, Bigliani LU 1997 Special considerations in the athletic throwing shoulder. Orthopedic Clinics of North America 28(1): 69–78 Basmajian JV, De Luca CJ 1985 Muscles Alive: Their Functions Revealed by Electromyography, 5th edn. Williams and Wilkins, Baltimore Bennell KL, Goldie PA 1994 The differential effects of external ankle support on postural control. Journal of Orthopedic and Sports Physical Therapy 20(6): 287–295 Blevins FT 1997 Rotator cuff pathology in athletes. Sports Medicine 24(3): 205–220 Bockrath K, Wooden C, Worrell T, Ingersoll CD, Farr J 1993 Effects of patella taping on patella position and perceived pain. Medicine and Science in Sports and Exercise 25(9): 989–992 Cools AM, Witvrouw EE, Declercq GA, Danneels LA, Willems TM, Cambier DC, Voight ML 2002 Scapular muscle recruitment pattern: electromyographic response of the trapezius muscle to sudden arm movement before and after a fatiguing exercise. J Orthop Sports Phys Ther 32(5): 221–229 Danneels LA, Cagnie BJ, Cools AM, Vanderstraeten GG, Cambier DC, Witvrouw EE, De Cuyper HJ 2001a Intra-operator and inter-operator reliability of surface electromyography in the clinical evaluation of back muscles. Manual Therapy 6(3): 145–153 Danneels LA, Vanderstraeten GG, Cambier DC, Witvrouw EE, Stevens VK, De Cuyper HJ 2001b A functional subdivision of hip, abdominal and back muscles during asymmetric lifting. Spine 26(6): E114–E121 # 2002 Elsevier Science Ltd. All rights reserved.
Taping and electromyographic muscle activity in shoulders 161 Davies GL, Dockoff-Hoffman S 1993 Neuromuscular testing and rehabilitation of the shoulder complex. Journal of Orthopedic Sports Physical therapy 18(2): 210–219 De Luca CJ 1997 The use of surface electromyography in biomechanics. Journal of Applied Biomechanics 13: 135–163 Engstro¨m BK, Renstro¨m PA 1998 How can injuries be prevented in the world cup soccer athlete? Clinics in Sports Medicine 17(4): 755–768 Feuerbach JW, Grabiner MD, Koh TJ, Weiker GG 1994 Effect of an ankle orthosis and ankle ligament anaesthesia on ankle joint proprioception. The American Journal of Sports Medicine 22(2): 223–261 Gilleard W, McConnell J, Parsons D 1998 The effect of patellar taping on the onset of vastus medialis obliquus and vastus lateralis muscle activity in persons with patellofemoral pain. Physical Therapy 78(1): 25–31 Glousman R, Jobe F, Tibone J, Moynes D, Antonelli D, Perry J 1988 Dynamic electromyographic analysis of the throwing shoulder with glenohumeral instability. The Journal of Bone and Joint Surgery 70A(2): 220–226 Greene TA, Wight CR 1990 A comparative support evaluation of three ankle orthoses before, during and after exercise. Journal of Orthopedic and Sports Physical Therapy 11: 453–466 Gross MT, Batten AL, Lamm AL 1994 Comparison of Donjoy ankle ligament protector and subtalar sling ankle taping in restricting foot and ankle motion before and after exercise. Journal of Orthopedic and Sports Physical Therapy 19(1): 33–41 Hancock RE, Hawkins RJ 1996 Applications of electromyography in the throwing shoulder. Clinical Orthopaedics and Related Research 330: 84–97. Hall CM 1999 The shoulder girdle. In: Hall CM, Brody LT (eds) Therapeutic Exercise: Moving Toward Function. Lippincott Williams and Wilkins, Philadelphia Heit EJ, Lephart SM, Rozzi SL 1996 The effect of ankle bracing and taping on joint position sense in the stable ankle. Journal of Sports Rehabilitation 5: 206–213 Host HH 1995 Scapular taping in the treatment of anterior shoulder impingement. Physical Therapy 75(9): 803–812 Jensen C, Vasseljen O, Westgaard RH 1993 the influence of electrode position on bipolar surface electromyogram recordings of the upper trapezius muscle. European Journal of Applied Physiology 67: 266–273 Jensen C, Westgaard R 1997 Functional subdivision of the upper trapezius muscle during low-level activation. European Journal of Applied Physiology 76: 335–339 Johnson G, Bogduk N, Nowitzke A, House D 1994 Anatomy and actions of the trapezius muscle. Clinical Biomechanics 9: 44–50 Kamkar A, Irrgang JI, Whitney SL 1993 Non-operative management of secondary impingement syndrome. Journal of Orthopedic and Sports Physical Therapy 17(5): 212–224 Karlsson J, Andreasson GO 1992 The effect of external ankle support in chronic lateral ankle joint instability: An electromyographic study. The American Journal of Sports Medicine 20(3): 257–261 Kelley MJ 1995 Anatomic and biomechanical rationale for rehabilitation of the athlete’s shoulder. Journal of Sports Rehabilitation 4: 122–154 Kelly BT, Kadrmas WR, Speer KP 1996 The manual muscle examination for rotator cuff strength: An electromyographic investigation. Journal of Orthopedic and Sports Physical Therapy 24(5): 581–588 Kendall FP, Kendall EK 1983 Muscles, Testing and Function. Williams and Wilkins, Baltimore Kibler WB 1998 The role of the scapula in athletic shoulder function. The American Journal of Sports Medicine 26(2): 325–337 Konradson L, Voight M, Hojsgaard C 1997 Ankle inversion injuries: the role of the dynamic defence mechanism. The American Journal of Sports Medicine 25(1): 54–58 Kowall MG, Kolk G, Nuber GW, Cassisi JE, Stern SH 1996 Patellar taping in the treatment of patellofemoral pain: A prospective randomized study. The American Journal of Sports Medicine 24(1): 61–65 Larsen B, Andreansen E, Urfer A, Mickeslon MR, Newhouse KE 1995 Patellar taping: A radiographic examination of the medial # 2002 Elsevier Science Ltd. All rights reserved.
glide technique. The American Journal of Sports Medicine 23(4): 465–470 Lindman R, Eriksson A, Thornell L-E 1990 Fiber type composition of the human male trapezius muscle: Enzymehistochemical characteristics. American Journal of Anatomy 189: 236–244. Lindman R, Eriksson A, Thornell L-E 1991 Fiber type composition of the human female trapezius muscle: Enzymehistochemical characteristics. American Journal of Anatomy 190: 385–392. Lohrer H, Alt W, Gollhofer A 1999 Neuromuscular properties and functional aspects of taped ankles. The American Journal of Sports Medicine 27(1): 69–75 Ludewig PM, Cook TM, Nawocsenski DA 1996 Threedimensional scapular orientation and muscle activity at selected positions of humeral elevation. Journal of Orthopedic and Sports Physical Therapy 24(2): 57–65 Lukasiewicz AC, McClure P, Michiner L, Pratt N, Sennett B 1999 Comparison of three dimensional scapular position and orientation between subjects with and without shoulder impingement. Journal of Orthopedic and Sports Physical Therapy 29(10): 574–586 McCann PD, Wootten ME, Kadaba MP, Bigliani LU 1993 A kinematic and electromyographic study of shoulder rehabilitation exercises. Clinical Orthopedics and Related Researches 288: 179–188 McConnell J. The Mc Connell approach to the problem shoulder. Taping: Inhibition of the upper trapezius muscle. 1999 Course Notes, p 34. McCaw ST, Cerullo JF 1999 Prophylactic ankle stabilizers affect ankle joint kinematics during drop landings. Medicine and Science in Sports and Exercise 31(5): 702–707 McMahon PJ, Jobe FW, Pink MM, Brault JR, Perry J 1996 Comparative electromyographic analysis of shoulder muscles during planar motions: Anterior glenohumeral instability versus normal. Journal of Shoulder and Elbow Surgery 5: 118–123 McQuade KJ, Dawson J, Smidt GL 1998 Scapulothoracic muscle fatigue associated with alterations in scapulohumeral rhythm kinematics during maximum resistive shoulder elevation. Journal of Orthopedic and Sports Physical Therapy 28(2): 74–80 Morin GE, Tiberio D, Austin G 1997 The effect of upper trapezius taping on electromyographic activity in the upper and middle trapezius region. Journal of Sports Rehabilitation 6: 309–319 Mottram SL 1997 Dynamic stability of the scapula. Manual Therapy 2(3): 123–131 Pink M, Perry J, Browne A, Scovacco ML, Kerrigan J 1991 The normal shoulder during free style swimming: An electromyographic and cinematographic analysis of twelve muscles. The American Journal of Sports Medicine 19: 569–576 Pink MM, Tibone JE 2000 The painful shoulder in the swimming athlete. Orthopedic Clinics of North America 31(2): 247–261 Robbins S, Waked E 1998 Factors associated with ankle injuries: Preventive measures. Sports Medicine 25(1): 63–72 Rupp S, Berninger K, Hopf T 1995 Shoulder problems in high level swimmersFimpingement, anterior instability, muscular imbalance? International Journal of Sports Medicine 16: 557–562 Sahrmann SA 2002 Diagnosis and treatment of Movement Impairment Syndromes, 1st edn., chapter 5, pp 193–245, Mosby, St.Louis Schmitt L, Snyder-Mackler L 1999 Role of scapular stabilizers in etiology and treatment of impingement syndrome. Journal of Orthopedic and Sports Physical Therapy 29(1): 31–38 Shamus JL, Shamus EC 1997 A taping technique for the treatment of acromioclavicular joint sprains: A case study. Journal of Orthopedic and Sports Physical Therapy 25(6): 390–394 Somes S, Worrell TW, Corey B, Ingersol CD 1997 Effects of patellar taping on patellar position in the open and closed kinetic chain: A preliminary study. Journal of Sports Rehabilitation 6: 299–308 Wadsworth DJ, Bullock-Saxton JE 1997 Recruitment patterns of the scapular rotator muscles in freestyle swimmers with subacromial impingement. International Journal of Sports Medicine 18: 618–624 Manual Therapy (2002) 7(3), 154–162
162 Manual Therapy Weiser WM, Lee TQ, McMaster WC 1999 Effects of simulated scapular protraction on anterior glenohumeral stability. The American Journal of Sports Medicine 27(6): 801–805 Wilk KE, Arrigo C 1993 Current concepts in the rehabilitation of the athletic shoulder. Journal of Orthopedic and Sports Physical Therapy 18(1): 365–378 Wilkerson GB 1991 Comparative biomechanical effects of the standard method of ankle taping and a taping method designed
Manual Therapy (2002) 7(3), 154–162
to enhance subtalar stability. The American Journal of Sports Medicine 19(6): 588–595 Winter DA, Fuglevand AJ, Archer SE 1994 Crosstalk in surface electromyography: Theoretical and practical estimates. Journal of Electromyography and Kinesiology 4: 15–26 Yang JF, Winter DA 1983 Electromyography reliability in maximal and submaximal isometric contractions. Archives of Physical Medicine and Rehabilitation 64: 417–420
# 2002 Elsevier Science Ltd. All rights reserved.