Upper Limb Neurodynamic Test of the Radial Nerve: A Study of Responses in Symptomatic and Asymptomatic Subjects

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Upper Limb Neurodynamic Test of the Radial Nerve: A Study of Responses in Symptomatic and Asymptomatic Subjects Cheryl M. Petersen, PT, DPT, DHS Concordia University Wisconsin, Mequon, Wisconsin

Chris L. Zimmermann, PT, PhD Concordia University Wisconsin, Mequon, Wisconsin

Kathy D. Hall, PT, EdD Midwestern University Downers Grove, Illinois

Steve J. Przechera, MPT, OCS, ATC Newsome Physical Therapy, Oswego, Illinois

Jenna V. Julian, DPT Elmhurst Memorial Healthcare, Elmhurst, Illinois

Nicole N. Coderre, DPT Marianjoy Rehabilitation Hospital, Wheaton, Illinois

BACKGROUND Clinical determination of the involved tissue associated with cervical dysfunction is necessary for facilitation of appropriate treatment. Cervical All the authors contributed equally to this work. A portion of the study was conducted as a research requirement while Mr. Przechera was a master of physical therapy student in the Department of Physical Therapy and Human Movement Sciences, Northwestern University Medical School. Ms. Julian and Ms. Coderre were students in the Department of Physical Therapy and Human Movement Sciences, Northwestern University Medical School, at the time when a portion of the study was conducted, as part of the DPT requirement. All students were supervised by Ms. Petersen. This study was approved by the Northwestern University Institutional Review Board. A portion of the study was funded by a grant by the Orthopaedic Section, APTA, Inc. This article was adapted from a presentation at the

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ABSTRACT: Study Design: Clinical measurement. Introduction: Nonspecific cervical pain is a common clinical presentation. The role of upper limb neurodynamic tests (ULNT), for evaluation and treatment intervention, is not well defined for this population. Purpose of the Study: This study’s purpose was to determine if the radial-biased (RB)-ULNT discriminates any response differences between symptomatic subjects with a positive (þ) RB-ULNT (n ¼ 36), symptomatic subjects with a negative () RBULNT (n ¼ 24), and asymptomatic subjects (n ¼ 60). Methods: Sixty asymptomatic and 60 subjects presenting with nonspecific cervical and/or unilateral upper extremity pain were compared using the RB-ULNT. Symptomatic subjects were further divided in (þ) and () RB-ULNT groups due to their response to the RB-ULNT. Within the symptomatic population, a positive response to the RB-ULNT was defined by the symptomatic subject reporting their sensations were increased with contralateral cervical lateral flexion and decreased with ipsilateral cervical lateral flexion. Sensation provocation and location were evaluated using the RB-ULNT in all the subjects during each stage of the testing. Results: Significant differences on stage of reproduction and type of sensations were identified between 1) the (þ) RB-ULNT symptomatic subjects, 2) the () RB-ULNTsymptomatic subjects, and 3) the asymptomatic subjects. The (þ) RB-ULNT group showed significantly increased pain responses during the first stage of the RB-ULNT compared with the () RB-ULNT group and the asymptomatic subjects. The (þ) RB-ULNT also showed significantly decreased glenohumeral abduction passive range of motion when compared with the asymptomatic group. Conclusion: Clinically, the differences found between the groups in their response to the RB-ULNT suggest heightened mechanosensitivity in the (þ) RB-ULNT group. Level of Evidence: 3a. J HAND THER. 2009;22:344–54.

dysfunction involving muscle and ligamentous tissues is typically more easily evaluated by therapists than is dysfunction involving peripheral nerves because most clinicians do not routinely have access to peripheral nerve diagnostic information for clients Combined Sections Meeting, American Physical Therapy Association, Tampa, FL in February 2003. Competing interests: The authors declare that they have no competing interests. Correspondence and reprint requests to Cheryl M. Petersen, PT, DPT, DHS, Concordia University Wisconsin, 12800 North Lake Shore Drive, Mequon, WI 53097; e-mail: . 0894-1130/$ e see front matter Ó 2009 Hanley & Belfus, an imprint of Elsevier Inc. All rights reserved. doi:10.1016/j.jht.2009.05.001

with nonspecific cervical and upper extremity (UE) pain. Mechanosensitivity within the nervous system is normal but can become abnormal after injury. Heightened (abnormal) mechanosensitivity is suggested clinically when a patient’s symptoms are induced/changed with limb movements that stress neural structures (upper limb neurodynamic tests [ULNTs]) or when patients present with decreased pain threshold after the application of pressure over nerves (palpation or tinel’s sign).1e3 Animal studies have shown pain-related behaviors associated with localized neuritis. This local inflammation can induce axonal mechanical sensitivity characterized by the recruitment of epineurial lymphocytes and macrophages. This cellular infiltrate is probably involved in creating the axonal mechanical sensitivity secondary to increased sodium conductance. Thus, pressure over intact nerve fibers at a lesion site will produce neural activity.4e8 Assessment of heightened peripheral nerve mechanosensitivity may be of benefit clinically to identify minor nerve pathophysiology.1 Mechanosensitivity assessment occurs through palpation of superficial nerves or with movement of the nerve throughout the nerve’s course.1,9e11 ULNT use is proposed to assess the mechanosensitivity and extensibility of the nervous structures of the upper quadrant. Dilley et al.1 found that mechanosensitivity occurred in functionally intact A delta and C fibers in locally inflamed rat nerves. These sensitive nerve fibers were a subpopulation of mechanosensitive pressure units responding to a 3e5% stretch. These values (3e5%) reflect nerve stretch ranges occurring during normal human limb movement.1 A patient’s sensory responses during an ULNT are thought to be produced by stimulation of the sensory nerves in the connective tissues of peripheral nerves.12,13 ULNTs are considered to suggest heightened mechanosensitivity when one or more of the following findings present in symptomatic patients: 1) reproduction of the patient’s symptoms during an ULNT,14e19 2) re-creation of the subject’s symptoms or decreases in the subject’s cervical range of motion (ROM) associated with a provocation maneuver such as contralateral cervical lateral flexion (CCLF) (increased neural tension), or decreases in the subject’s symptoms or increases in the subject’s cervical ROM associated with an alleviation maneuver such as ipsilateral CLF (ICLF) (decreased neural tension),18,20e22 3) UE ROM differences are found with testing,14,15,17,19,23,24 4) a muscle spasm end-feel occurs with the ULNT, suggesting pathology,22,25e27 or 5) an abnormal motor response results.28e30 A neurologic examination can test the ability of nerves to conduct a signal, whereas the ULNTs can test for heightened mechanosensitivity.1,29 Peripheral nerves must be able to withstand compression and tension, and slide longitudinally and

transversely within their sleeve for normal function. Pressure and tension can both produce ischemia and reduced conduction and axonal transport.1,31,32 Nerve pressure and stretch can be increased or decreased, respectively14,31 when the intervertebral foramen are closed or opened with movement, such as with ICLF or CCLF in humans. Minor injuries or inflammation of human peripheral nerves may produce increased sensitivity to mechanical loading without documented nerve conduction changes.28e30,33 Nerves become ischemic when they are elongated, demonstrated in rabbit studies. With a 6% strain to rabbit nerve for one hour, the action potential amplitude decreased by 70%, returning to normal after release. Blood flow to rabbit peripheral nerves slowed at approximately 6e8% strain.34,35 It was concluded from the rabbit studies involving compression that acute nerve compression may cause localized interference of microvascular function from the mechanical injury to the blood vessels with time as minimal as within minutes.36e38 The critical values for pressure and duration for nerve injury are not known. Therefore, during an ULNT, neural ischemia may create symptoms, secondary to elongation and compression from neighboring tissue. Specific variation in stress and strain in the median, radial, and ulnar nerves has been shown to occur between the various ULNT positions and with CCLF and rotation.17,23,39 The ULNT position for each specific UE nerve (median, ulnar, and radial) has been studied in cadavers.23,39 Contralateral flexion has produced increased cadaver nerve force buckle transducer measurements, suggesting increased nerve tension. Increased nerve force buckle transducer measurements have been associated with the UE positioning used for the different peripheral nerves. Positioning used for clinical ULNTs are based on these findings. CCLF increased symptoms evoked by the radial-nerve biased ULNT (RB-ULNT)40 and with the median-nerve biased ULNT.19,41,42 The component movements of the RB-ULNT (Table 1) apply mechanical stress to the radial nerve.9,11,37,43,44 Shoulder girdle depression increases the distance between the neck and arm increasing tension in UE peripheral nerves via the cervical nerve roots and the brachial plexus.45e48 Glenohumeral (GH) abduction increases the length between the coracoid process and a midpoint on the shaft of the humerus by about 2.4 cm, resulting in increased tension occurring in the brachial plexus and the distal aspect of the peripheral nerves.39,48e50 Radial nerve tension increases with GH internal rotation.39 Passive pronation stretches the supinator muscle resulting in up to 46 mm Hg pressure on the posterior interosseous (PI) nerve at the supinator tunnel.51 Wrist and finger flexion tightens the extensor carpi radialis brevis to which the PI nerve attaches. With

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TABLE 1. The Radial-Biased Upper Limb Neurodynamic Test Stages

Sequential Stages of RB-ULNT

Subject Testing Differences Symptomatic versus Asymptomatic

Appropriate End-feels27 for End Range Motions

1. Passive shoulder girdle depression, elbow extension, and GH frontal plane abduction to 108

Performed on both populations

Muscular for shoulder girdle depression, hard for elbow extension

2. Passive shoulder internal rotation and forearm pronation

Performed on both populations

Capsular

3. Passive wrist and finger flexion and ulnar deviation

Performed on both populations

Capsular

4. Passive GH abduction

Performed on both populations

Capsular

5. Passive CCLF1

Performed on both populations

Capsular

6. Cervical neutral

Performed on symptomatic only

7. Passive ICLF

Performed on symptomatic only

8. Cervical neutral

Performed on symptomatic only

9. Cervical neutral 8 with 10 passive GH abduction in the frontal plane

Performed on both populations

10. Passive CCLF2

Performed on both populations

11. Neck and upper extremity returned to the resting position with shoulder girdle depression released

Performed on both populations

Capsular

Capsular

In stages 1 through 5, the movements of subsequent stages were added to each previous stage. Stages 6e8 were performed only with the symptomatic subjects. At stage 6, the arm was returned to the pretesting position. For all subjects, stage 10 was additive to stage 9. The bolded information relates to the symptomatic subjects only. RB-ULNT ¼ radial-biased upper limb neurodynamic test; GH ¼ glenohumeral; CCLF1 ¼ contralateral cervical lateral flexion time 1; CCLF2 ¼ contralateral cervical lateral flexion time 2; ICLF ¼ ipsilateral cervical lateral flexion.

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flexion/adduction of the thumb and ulnar deviation of the wrist, tension is applied to the radial sensory nerve.39,52 Three studies have evaluated passive ROM (PROM) differences during passive GH abduction.40,53,54 A mean GH abduction range of 41.58 was reported in one study of 50 asymptomatic subjects using the RB-ULNT.53 Two additional studies involved symptomatic subject findings.40,54 Fifteen subjects employed as screen-based keyboard operators (SBKOs) with work-related neck and upper limb disorders54 were compared with ten nonSBKO controls. Significant differences in mean GH abduction were found during the RB-ULNT between the controls with 408 of GH abduction compared with the symptomatic SBKO subjects (278 right and 308 left).54 Measurements for the SBKO involved both shoulders as both UEs are used with screen-based work. GH abduction was also evaluated bilaterally in 20 subjects with unilateral tennis elbow.40 Significantly decreased GH abduction was found comparing the asymptomatic (36.68 ) and symptomatic sides (24.28 ) of the subjects with tennis elbow. These ROM differences are considered criteria for a positive ULNT.14,17,19,23,24 A stretch sensation over the lateral aspect of the proximal forearm has been the most commonly reported sensation in these previous studies, with differences found between the symptomatic and asymptomatic subjects.40,54 More subjects employed as the SBKO with work-related neck and upper limb disorders (40%) experienced a stretch sensation during GH depression compared with only 20% of the control group.54 The qualitative description of the stretch was described differently in the subject’s involved tennis elbow side as a strong tennis elbow pain versus the same subject’s uninvolved side description of stretch pain.40 Although these three studies40,53,54 evaluating the RB-ULNT provide useful preliminary data, more subject testing is needed to establish normative responses for symptomatic compared with asymptomatic subject groups, and to determine whether the RB-ULNT is discriminatory in patients with nonspecific cervical and UE pain. The purpose of the present study was to compare responses to the RB-ULNT between symptomatic subjects with a positive (þ) RB-ULNT (n ¼ 36), symptomatic subjects with a negative () RB-ULNT (n ¼ 24), and asymptomatic subjects (n ¼ 60). Three hypotheses were tested: 1) the (þ) RB-ULNT symptomatic group would report sensation(s) earlier during the RB-ULNT sequential testing compared with the other groups, 2) the (þ) RB-ULNT group would report different sensations and locations of sensations on their involved side compared with the other groups, and 3) the (þ) RB-ULNT group would have significantly less PROM measurements in their involved side compared with the other groups.

TABLE 2. Descriptive Characteristics of the Subjects and p-Value for Differences Between Groups

Height (m) Weight (kg) BMI Age (yr)

36 (þ) RB-ULNT Symptomatic Subjects

24 () RB-ULNT Symptomatic Subjects

60 Asymptomatic Subjects

Mean and SD

Mean and SD

Mean and SD

p-Values

1.69 6 4.1 72.0 6 37.4 25.1 6 5.3 39.4 6 14.4

1.68 6 3.2 63.1 6 24.2 22.4 6 2.7 32.7 6 13.1

1.69 6 3.7 63.9 6 26.3 22.1 6 2.8 25.9 6 5.2

0.45 0.03 0.004 0.000

Frequencies Gender Hand Dominance Symptom Location Cervical only UE only Cervical & UE

Frequencies

25 females 11 males 35 right 1 left

20 4 22 2

2 3 30

8 6 11

Frequencies

females males right left

42 18 55 5

females males right left

0.000

0.54

No symptoms

RB-ULNT ¼ radial-biased upper limb neurodynamic test; BMI ¼ body mass index; SD ¼ standard deviation; UE ¼ upper extremity.

METHODS Subjects One hundred twenty UEs from 60 asymptomatic subjects, ranging in age from 22 to 45 years, were evaluated using the RB-ULNT (see Table 2). The asymptomatic subjects presented without cervical or UE symptoms during active ROM (AROM), PROM, and overpressures to the cervical spine, and without positive neurologic test findings (sensory, motor, and deep tendon reflex testing). Sixty symptomatic subjects, primarily referred from two clinics, were tested two years later for comparison purposes. A convenience sample of 60 subjects with nonspecific cervical only and with unilateral UE pain, ranging in age from 21 to 69 years, participated in the study. Participants completed a questionnaire to determine final eligibility. All subjects had to have sensation(s) in at least one of the following regions: 1) unilateral cervical region, 2) unilateral cervical and UE regions, or 3) bilateral cervical and unilateral UE regions. Subjects with bilateral UE involvement were excluded. Reproduction of the subject’s sensation(s) had to be present with cervical AROM and/or PROM testing with or without limitation of cervical movements. To increase reliability of the examination between the two groups who examined subjects in different settings, multiple training sessions were performed before initiation of the study (no statistical analysis performed). These sessions consisted of an initial two hours of training, completed on asymptomatic subjects, for consistency of the placement of landmarks, neurologic (dermatomal, myotomal, and deep tendon reflex testing, Phalen’s test, and tinel’s sign for the median, radial, and ulnar nerves) and

RB-ULNT testing. These two examining groups practiced separately with a final session to observe the consistency of techniques demonstrated by the two groups of examiners as they evaluated the same subjects alternately. The subjects were faculty and/ or clinicians from the referral sites with symptoms. The faculty and/or clinicians, as well as one of the authors (CMP), observed and graded the evaluation techniques. Information to increase consistency of testing was shared such as differences in pressure or hand placement, techniques were practiced and examiners were then reevaluated. We chose to use both the subject’s reproduction of their presenting symptoms and alteration of those symptoms with both CCLF and ICLF as the definition of a positive response to the RB-ULNT used in this study. This created two groups within our symptomatic population: 1) symptomatic subjects with positive reproduction and alleviation of their symptom(s) with cervical movements ([þ] RBULNT) and 2) symptomatic subjects not meeting the above criteria ([] RB-ULNT). The (þ) RB-ULNT group met two criteria: 1) subject’s presenting symptoms increased with CCLF (Table 1, stage 5) and 2) subject’s presenting symptoms decreased with ICLF (Table 1, stage 7). The 60 symptomatic subjects (36 with a (þ) RB-ULNT and 24 with a () RB-ULNT) were compared with 60 asymptomatic subjects (testing both sides for a total of 120 UEs).

Exclusion Criteria Exclusion criteria for the study groups included central nervous system disease, distal peripheral nervous system injury involving the median or ulnar nerve, systemic arthritis, cervical spine or UE fracture OctobereDecember 2009 347

FIGURE 1. Patient positioning in the stabilization device for testing the radial-biased upper limb neurodynamic test. within the last three months, cervical spine or UE surgery within the last three months, and bilateral UE symptoms. Potential subjects were also excluded if they had a side-to-side difference of greater than 108 PROM in GH abduction, GH internal rotation, elbow extension, forearm pronation, wrist flexion, wrist ulnar deviation, finger flexion, or CLF. This procedure ensured that differences in ROM during the testing were not due to a pre-existing condition. Subjects who qualified provided informed consent before the testing procedure. Subject characteristics of each group are summarized in Table 2.

Protocol Reference points were marked on the subjects’ acromion bilaterally, for alignment of the stabilization device, (see Figure 1) and on the sternal notch, for CLF measurements. Subjects were placed supine on a plinth (centered within the stabilization device, with the cervical spine in an observed neutral position). The stabilization device was custom-made and used to hold the shoulder in maximal depression during the test. Maximal shoulder depression was determined by end-feel testing until resistance was met by the strain on the soft tissues by the examiner.27 The subjects were given instructions on the testing process and asked to lie completely still during the test with their legs uncrossed and the opposite extremity at their side or across their abdomen. Subjects were also told that they could stop the test at any point, if the testing became unbearable. During the symptomatic group testing, blinding to the side of involvement was used and the side of testing was randomly assigned. The procedure for the RB-ULNT is reported in Table 1. A list of seven sensations including ache, burn, numbness, pain, pressure, stretch, and tingling55 was placed on the ceiling above the testing plinth. Before the test, subjects were told that they could describe their sensations using one or more of the words provided, or any other word(s) that 348

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most closely represented the sensation experienced. The subjects were asked to describe the location and sensation(s) they felt at each stage of the RB-ULNT. One examiner performed all of the UE passive movements. The second examiner performed the cervical movements and goniometric measurements. Shoulder girdle depression was measured in centimeters using a meter tape secured to the stabilization device. A 3608 goniometer was used to document the PROM of GH abduction and CCLF measured in stages 1, 4, 5, 9, and 10 (see Table 1).56 GH abduction was measured using the GH head as the axis for the goniometer with the two arms placed over the humeral longitudinal axis and parallel to the sternum. CLF was measured with the axis placed over the marked sternal notch with the two arms aligned parallel with the line of the nose and the sternum. Three training sessions were conducted for consistency in landmark placement. However, reliability analysis was not performed. A third examiner recorded the goniometric measurements, the subject’s report of sensation(s) and location of the sensation(s) at every stage of the test. Stages 1e5, 7, and 10 were performed to an appropriate end-feel unless the subject asked to stop the passive movements. End-feels vary per joint due to the specific anatomy at each joint complex. The end-feels used in this study are summarized in Table 1.27

Data Analysis The dependent variables included the RB-ULNT stage of first sensation onset (SOFS); the descriptors of sensations (ache, burn, numbness, pain, pressure, stretch, and tingling); location of sensations reported at each stage of the RB-ULNT during testing; and PROM. Nerve distributions were identified by comparing each subject’s documented verbal description of sensation location during the RB-ULNT to an anatomical peripheral nerve distribution.57 The nonparametric KruskaleWallis one-way analysis of variance (ANOVA) test was used to evaluate SOFS, the seven sensations and eight locations with post hoc testing using ManneWhitney U.58 A oneway ANOVA was used to determine if there were differences between the groups in PROM for shoulder depression and abduction, and for CCLF time 1 and time 2. Statistical analyses were performed using SPSS 17.0 software program (SPSS Inc., 233 S. Wacker Drive, 11th Floor, Chicago, IL). Differences were regarded as significant at the p , 0.05 level. Effect size (Cohen’s d) was used to evaluate the PROM differences between the groups.

xt  xc Cohen0 s d : d ¼ qffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi ðnt 1Þst þ ðnc 1Þsc nt þ nc

FIGURE 2. Frequency of the stage of first sensation reported during the radial-biased upper limb neurodynamic test.

RESULTS

(p ¼ 0.000) and 2) the (þ) RB-ULNT group and the () RB-ULNT group (p ¼ 0.002).

Subjects Significant differences were found between the groups as seen in Table 2. The subjects were not matched.

SOFS Figure 2 graphs the first four stages of the RBULNT findings by group. By stage 4, all subjects in both the symptomatic and asymptomatic groups reported sensations. Stage 1 through 4 for the RBULNT showed that the (þ) RB-ULNT subjects were more likely (x2 ¼ 6.3, p ¼ 0.001) than the other groups to report a sensation during stage 1 (shoulder depression). Forty-nine percent of the (þ) RB-ULNT group, 28% of the () RB-ULNT group, and 8% of the asymptomatic group reported their first sensation during stage 1. On post hoc testing, there were significant differences between the following: 1) the (þ) RB-ULNT group and the asymptomatic group

Type of Sensation Reported Frequencies for the type of sensation reported are presented in Figure 3. All groups reported stretch, pain, tingling, and numbness as common sensations. However, stretch was the most commonly reported sensation. Although common to all groups, both pain and stretch were significantly different between groups (x2 ¼ 22.0, p ¼ 0.000; x2 ¼ 14.6, p ¼ 0.002, respectively) using the KruskaleWallis ANOVA test. The reported frequencies for pain were significantly different between the asymptomatic group and the (þ) RB-ULNT (p ¼ 0.000) as well as between the (e) RB-ULNT subjects (p ¼ 0.024). The reported frequencies for stretch were significantly different between the asymptomatic group and the (þ) RB-ULNT subjects (p ¼ 0.000). No statistical differences were reported for tingling and numbness.

FIGURE 3. Frequency of sensations (ache, burn, numbness, pain, pressure, stretch, and tingling) reported through the radial-biased upper limb neurodynamic test stages. OctobereDecember 2009 349

TABLE 3. Mean and Standard Deviation, and Confidence Interval for PROM Measurements During the RB-ULNT

(þ) RB-ULNT symptomatic subjects CI (upperelower bound) () RB-ULNT symptomatic subjects CI (upperelower bound) Asymptomatic subjects CI (upperelower bound)

Shoulder Girdle Depression (cm)

Shoulder Abduction

CCLF1

CCLF2

4.0 6 1.2 3.6, 4.4 4.2 6 1.0 3.7, 4.6 4.1 6 1.1 3.8, 4.4

31.18 6 11.28 27.3, 34.8 33.98 6 12.88 28.2, 39.6 37.38 6 12.08 34.2, 40.4

13.88 6 5.18 12.1, 15.6 12.58 6 5.98 9.98, 14.9 13.48 6 6.08 11.8, 14.9

18.78 6 7.38 17.4, 23.3 20.48 6 8.48 16.2, 23.4 18.68 6 7.38 16.8, 20.6

PROM ¼ passive range of motion; RB-ULNT ¼ radial-biased upper limb neurodynamic test; CCLF1 ¼ contralateral cervical lateral flexion time 1; CCLF2 ¼ contralateral cervical lateral flexion time 2; CI ¼ confidence interval.

PROM The mean and standard deviation for PROM recorded for shoulder depression in stage 1, GH abduction in the frontal plane in stage 4, for CCLF time 1 (CCLF1) in stage 5 and CCLF time 2 (CCLF2) in stage 10, are presented in Table 3. A one-way ANOVA was significant for shoulder abduction (p ¼ 0.05). Post hoc testing showed a significant difference between the asymptomatic and the (þ) RBULNT groups (p ¼ 0.04). A medium effect size (d ¼ 0.40e0.49)58 was found between the asymptomatic group and the (þ) and () RB-ULNT groups for shoulder abduction.

Sensation Distribution Frequencies for the distribution of sensation location (neck, upper arm, olecranon, cubital fossa, lower

extensor region, dorsal wrist, thumb and fingers) reported during testing are displayed in Figure 4. The RB-ULNT produced no significant differences in the frequency of the sensation distribution between the groups. All subject groups reported sensations throughout the radial nerve distribution especially the extensor forearm area (68% overall) that compares to the results of Yaxley and Jull [53] (1991). All groups had reports of sensation in the median and ulnar nerve distributions as well.

DISCUSSION The purpose of this study was to investigate responses to the RB-ULNT in subjects with nonspecific cervical only and with UE pain and asymptomatic subjects. Statistically significant differences between the groups were found for the stage of

FIGURE 4. Frequency of the distribution of sensation locations (fingers, thumb, dorsal wrist, extensor forearm, cubital fossa, olecranon, anterior upper arm, neck) reported through the RB-ULNT stages. 350

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sequential testing using the RB-ULNT when first symptom reproduction occurred, differences in PROM for GH abduction and with reports of pain and stretch during testing.

Stage of First Symptom The first hypothesis that the (þ) RB-ULNT subjects would experience their first sensation at an earlier stage in the sequential stages of the RB-ULNT was statistically supported (Figure 2). Significantly more of the (þ) RB-ULNT subjects (49%) reported their first sensation in response to stage 1 than either the () RB-ULNT group (28%) or the asymptomatic group (7%). Our asymptomatic findings for stage 1 were consistent with Yaxley and Jull53 who found that shoulder depression caused sensations in only 11% of their asymptomatic subjects. A possible explanation for our (þ) RB-ULNT subjects experiencing their first sensation in their involved arms during stage 1 may be that these subjects did present with radial nerve problems.

Type of Sensation Reported Similar to the findings of Yaxley and Jull40 and Friberg et al.,59 stretch was the most commonly reported sensation during testing by subjects in all groups. Significant differences were found with post hoc testing between the asymptomatic group and the (þ) RB-ULNT group with more asymptomatic subjects experiencing stretch (a normal sensation) with testing. Because all movements during the test procedure, except for the 108 of GH abduction, were performed to end-range, either by endfeel or self-reported stop, it is possible that the mechanical tension placed on the muscles and soft tissue resulted in the stretch sensation felt by all subjects. Stretch was a common sensation for all groups, similar to the results of other studies.14,24,40,54,59 Pain was one of the four sensations commonly reported in our study, and was reported as frequently as stretch in the (þ) RB-ULNT (69%). For the () RBULNT group, pain was the second most frequently reported sensation (44%). Pain had the lowest frequency (20%) in the asymptomatic group (see Figure 3). Pain presentation may indicate sufficient stretch1 to activate A delta and C fibers in subclinically inflamed nervous tissue in the symptomatic population in particular. When using the RB-ULNT, pain could identify differences between individuals with radial nerve involvement and individuals with involvement of different nerves or no neural involvement. Other than pain and stretch between the asymptomatic and the (þ) RB-ULNT, the type of sensation did not differentiate the groups within the study. Stretch, a normal response was significantly greater in the asymptomatic group.

PROM Analysis of the PROM measurements revealed no significant differences between groups except for shoulder abduction. Our PROM findings for shoulder abduction were similar to previous studies (Table 3).53,54,60 Yaxley and Jull,53 reported approximately 418 6 48 of GH abduction in asymptomatic subjects, and Howard60 reported left and right, 418 6 58 and 438 6 58 , respectively in asymptomatic subjects compared with our 378 6 128 . Passive GH abduction for our (þ) RB-ULNT group (318 ) was significantly less compared with the asymptomatic group (378 ). Grant et al.54 reported similar significant differences between the asymptomatic and symptomatic individuals (408 and 278 e308 , respectively). Our third hypothesis, PROM measures would be significantly less in the (þ) RB-ULNT group compared with the asymptomatic group was supported statistically for shoulder abduction and the effect size differences for shoulder abduction (asymptomatic and (þ) and () RB-ULNT) indicated clinically different ROM measurements between these three groups. The finding for the () RB-ULNT group may be due to involvement of other nervous tissue; as shoulder abduction is a component for ULNTs for the median and ulnar nerves as well. PROM in this study did differentiate between the asymptomatic and the (þ) RB-ULNT groups.

Symptom Distribution No statistically significant differences in reported sensations across the eight locations (neck, upper arm, olecranon, cubital fossa, lower extensor region, dorsal wrist, thumb and fingers) were found between any of the populations. Our second hypothesis that the symptomatic population would report different sensation distributions was not supported. Symptoms were also reported within the median and ulnar nerve distributions, in agreement with previous studies.14,24,60 Non-neural structures may be implicated with these findings.

Limitations In clinical practice, physical therapists use the ULNTs by gradually loading part of the nervous system to assess heightened mechanosensitivity and/or changes in the extensibility of nervous tissue in patients with nonspecific cervical dysfunction.1,25 Diagnoses of specific peripheral nerve involvement are not routinely available in most clinical practices. Thus, our symptomatic subjects did not have specific radial nerve diagnoses and often did not have any diagnosis; a limitation of our study and clinical practice. Another limitation is that the examiners’ were not blinded while evaluating the asymptomatic population. They were not aware of the involved side in the OctobereDecember 2009 351

symptomatic population although they were aware that these subjects had cervical and/or UE involvement to qualify for the study. A third limitation is the lack of quantified intertester reliability. A custommade stabilization device was used to maintain shoulder depression. The lack of such devices in the clinical setting is a limitation and the use of such stabilization devices, should be considered for clinical practice. A point of interest, related to the differences in the unmatched groups, was that the subjects with greater age and higher body weight presented as the (þ) RBULNT group. With aging, nerves are less able to adapt to changes in tension because of changes in the connective tissue coverings, deterioration of the myelin sheath, and the atherosclerosis of the blood vessels to the nerves. The additional body weight may have produced increased nerve compression force as well.61,62

Future Research The symptomatic population used in this study presented with nonspecific cervical and UE pain, many without a specific diagnosis. Future studies, evaluating the RB-ULNT with radial nerve pathology, could help determine whether similar findings of pain occur in stage 1 of the testing protocol. In the era of cost containment, clinical tests that are highly correlated with gold standard neurologic testing, should be used by therapists treating clients. Further study is needed to categorize patients with cervical pain to allow differentiation for appropriate interventions. Whether ULNT application may provide appropriate intervention for more than one category of cervical involvement remains to be evaluated.

CONCLUSION This study demonstrated significant differences between the (þ) RB-ULNT groups’ involved UEs versus asymptomatic subjects when using the RBULNT. The () RB-ULNT group’s response may have been due to involvement of the median or ulnar nerve. These ULNTs were not tested. The (þ) RBULNT subjects demonstrated reproduction of their symptoms and alteration of these sensations with CCLF or ICLF during the RB-ULNT, suggesting heightened mechanosensitivity within the radial nerve. Significantly more subjects within the (þ) RB-ULNT group reported sensations during the first stage of RB-ULT testing than did subjects in the other groups. Pain, as a sensation, was reported significantly more in both symptomatic groups compared with the asymptomatic group and the frequency was the highest in the (þ) RB-ULNT group. PROM differences were found for decreased GH abduction between the (þ) RB-ULNT and the asymptomatic groups. Decreased ROM findings again are 352

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suggestive of heightened nerve mechanosensitivity. Clinically, when the client’s presenting symptom occurs during the RB-ULNT’s first stage of testing, and if pain is the reported sensation in clients with nonspecific cervical pain, with or without unilateral UE symptoms, heightened mechanosensitivity within the radial nerve should be suspected.

REFERENCES 1. Dilley A, Lynn B, Pang SJ. Pressure and stretch mechanosensitivity of peripheral nerve fibres following local inflammation of the nerve trunk. Pain. 2005;117(3):462–72. 2. Greening J, Dilley A, Lynn B. In vivo study of nerve movement and mechanosensitivity of the median nerve in whiplash and non-specific arm pain patients. Pain. 2005;115:248–53. 3. Michaelis M, Blenk K-H, Janig W, Vogel C. Development of spontaneous activity and mechanosensitivity in axotomized afferent nerve fibers during the first hours after nerve transection in rats. J Neurophys. 1995;74(3):1020–6. 4. Chacur M, Milligan ED, Gazda LS, et al. A new model of sciatic inflammatory neuritis (SIN): induction of unilateral and bilateral mechanical allodynia following acute unilateral peri-sciatic immune activation in rats. Pain. 2001;94:231–44. 5. Elisav E, Herzberg U, Ruda MA, Bennett GJ. Neuropathic pain from an experimental neuritis of the rat sciatic nerve. Pain. 1999;83:168–82. 6. Bove GM, Ransil BJ, Lin HC, Leem JG. Inflammation induces ectopic mechanical sensitivity in axons of nociceptors innervating deep tissues. J Neurophysiol. 2003;90:1949–55. 7. Eliav E, Benoliel R, Tal M. Inflammation with no axonal damage of the rat saphenous nerve trunk induces ectopic discharge and mechanosensitivity in myelinated axons. Neurosci Lett. 2001;311:49–52. 8. Chen C, Cavanaugh JM, Song Z, Takebayashi T, Kallakuri S, Wooley PH. Effects of nucleus pulposus on nerve root neural activity, mechanosensitivity, axonal morphology, and sodium channel expression. Spine. 2003;29(1):17–25. 9. Elvey RL. Physical evaluation of the peripheral nervous system in disorders of pain and dysfunction. J Hand Ther. 1997;10(2): 122–9. 10. Sarhadi NS, Korday SN, Bainbridge LC. Radial tunnel syndrome: diagnosis and management. J Hand Surg [Br]. 1998; 23:617–9. 11. Uchihara T, Furukawa T, Tsukagoshi H. Compression of brachial plexus as a diagnostic test of cervical cord lesion. Spine. 1994;19:2170–3. 12. Devor M. The pathophysiology of damaged peripheral nerves. In: Wall PD, Melzack R (eds). Textbook of Pain. Edinburgh, UK: Churchill Livingstone, 1994. 13. Sauer SK, Bove GM, Averbeck B, Reeh PW. Rat peripheral nerve components release calcitonin gene-related peptide and prostaglandin E2 in response to noxious stimuli: evidence that nervi nervorum are nociceptors. Neuroscience. 1999;92:319–25. 14. Coppieters M, Stappaerts K, Everaert DG, Staes FF. Addition of test components during neurodynamic testing: effect on range of motion and sensory responses. J Orthop Sports Phys Ther. 2001;31(5):226–37. 15. Coppieters M, Stappaerts K, Janssens K. Reliability of detecting ‘onset of pain’ and ‘submaximal pain’ during neural provocation testing of the upper quadrant. Physiother Res Int. 2002; 7(3):146–56. 16. Quintner JL. A study of upper limb pain and paraesthesiae following neck injury in motor vehicle accidents: assessment of the brachial plexus tension test of Elvey. Brit J Rheumatol. 1989;28:528–33. 17. Sweeney J, Harms A. Persistent mechanical allodynia following injury of the hand. Treatment through mobilization of the nervous system. J Hand Ther. 1996;9:328–37.

18. Coppieters MW, Kurz K, Mortensen TE, et al. The impact of neurodynamic testing on the perception of experimentally induced muscle pain. Man Ther. 2005;10:52–60. 19. Selvaratnam PJ, Matyas TA, Glasgow EF. Noninvasive discrimination of brachial plexus involvement in upper limb pain. Spine. 1994;19:26–33. 20. Elvey RL, Quintner JL, Thomas AN. A clinical study of RSI. Aust Fam Physician. 1986;15(10):1314–20. 21. Hall TM, Elvey RL. Nerve trunk pain: physical diagnosis and treatment. Man Ther. 1999;4(2):63–73. 22. Shacklock MO. Positive upper limb tension test in a case of surgically proven neuropathy: analysis and validity. Man Ther. 1996;1(3):154–61. 23. Kleinrensink GJ, Stoeckart R, Vleeming A, Snijders CJ, Mulder PGH. Mechanical tension in the median nerve. The effects of joint positions. Clin Biomech (Bristol, Avon). 1995;10(5):240–4. 24. Coppieters MW, Stappaerts KH, Wouters LL, Janssens K. The immediate effects of a cervical lateral glide treatment techniques in patients with neurogenic cervicobrachial pain. J Orthop Sports Phys Ther. 2003;33:369–78. 25. Coppieters MW, Stappaerts KH, Staes FF, Everaert DG. Shoulder girdle elevation during neurodynamic testing: an assessable sign. Man Ther. 2000;6(2):88–96. 26. Cowell IM, Phillips DR. Effectiveness of manipulative physiotherapy for the treatment of a neurogenic cervicobrachial pain syndrome: a single case study—experimental design. Man Ther. 2002;7:31–8. 27. Cyriax J. Orthopaedic Medicine Volume One: Diagnosis of Soft Tissue Lesions. London, UK: Bailliere Tindall, 1978. 79e80. 28. Calvin WH, Devor M, Howe JF. Can neuralgias arise from minor demyelination? Spontaneous firing, mechanosensitivity, and afterdischarge from conducting axons. Exp Neurol. 1982; 75:755–63. 29. Kuslich SD, Ulstrom CL, Michael CJ. The tissue origin of low back pain and sciatica: a report of pain response to tissue stimulation during operations on the lumbar spine using local anaesthesia. Orthop Clin North Am. 1991;22:181–7. 30. Asbury AK, Field HL. Pain due to peripheral nerve damage: a hypothesis. Neurology. 1984;34:1587–90. 31. Butler DS. The Sensitive Nervous System. Unley, South Australia: NoiGroup Publications, 2000. 32. Shacklock M. Clinical Neurodynamics: A New System of Musculoskeletal Treatment. Edinburgh, UK: Elsevier Butterworth Heinemann, 2005. 33. Greening J, Lynn B. Minor peripheral nerve injury: an underestimated source of pain? Man Ther. 1998;3:187–94. 34. Ogata K, Naito M. Blood flow of peripheral nerve: effects of dissection, stretching and compression. J Hand Surg [Br]. 1986;11:10–4. 35. Lundborg G, Rydevik B. Effects of stretching the tibial nerve of the rabbit. J Bone Joint Surg [Br]. 1973;55:390–401. 36. Rydevik B, Lundborg G, Bagge U. Effects of graded compression on intraneural blood flow: an in-vivo study on rabbit tibial nerve. J Hand Surg. 1981;6:3–12. 37. Rempel D, Dahlin L, Lundborg G. Pathophysiology of nerve compression syndromes: response of peripheral nerves to loading. J Bone Joint Surg Am. 1999;81:1600–10. 38. Dyck PJ, Lais AC, Giannini C, Engelstad JK. Structural alterations of nerve during cuff compression. Proc Natl Acad Sci USA. 1990;87(24):9828–32. 39. Kleinrensink GJ, Stoeckart R, Mulder PGH, et al. Upper limb tension tests as tools in the diagnosis of nerve and plexus lesions: anatomical and biomechanical aspects. Clin Biomech (Bristol, Avon). 2000;15:9–14.

40. Yaxley GA, Jull GA. Adverse tension in the neural system. A preliminary study of tennis elbow. Aust J Physiother. 1993; 39(1):15–22. 41. Keanneally M, Rubenach H, Elvey RL. The upper limb tension test: the SLR of the arm. In: Grant R (ed). Physical Therapy of the Cervical and Thoracic Spine. New York, NY: Churchill Livingstone, 1988:167–94. 42. Selvaratnam P, Cook S. Matyas T. Transmission of mechanical stimulation to the median nerve at the wrist during the upper limb tension test. In: Proceedings of the 10th Biennial Conference of the Manipulative Physiotherapists’ Association of Australia, Melbourne 1997, pp. 182e8. 43. Carlan D, Pratt J, Patterson MM, Weiland AJ, Boyer MI, Gelberman RH. The radial nerve in the brachium: an anatomic study in human cadavers. J Hand Surg [Am]. 2007;32(8):1177–82. 44. Kato N, Birch R. Peripheral nerve palsies associated with closed fractures and dislocations. Injury. 2006;37:507–12. 45. Frykholm R. The mechanism of cervical radicular lesions resulting from friction or forceful traction. Acta Chir Scand. 1951;102:93–8. 46. Smith C. Changes in length and position of the segments of the spinal cord with changes in posture in the monkey. Radiology. 1956;66:259–65. 47. Reid J. Ascending nerve roots. J Neurosurg. 1960;23:148–55. 48. Adams C, Logue V. Studies in cervical spondylotic myelopathy: movement of the cervical roots, dura and cord and their relation to the course of the extrathecal roots. Brain. 1971;94:557–68. 49. Selvaratnam P, Glasgow E, Matyas T. Strain effects on the nerve roots of brachial plexus. J Anat. 1988;161:260–4. 50. Wright T, Glowczewskie F, Wheeler D, Miller G, Cowin D. Excursion and strain of the median nerve. J Bone Joint Surg [Am]. 1996;78(12):1897–903. 51. Werner C, Rosen I, Thorngren K. Clinical and neurophysiologic characteristics of the pronator syndrome. Clin Orthop. 1985;197:231–7. 52. Sunderland S. Nerves and Nerve Injury. 2nd ed. Edinburgh, UK: Churchill Livingstone, 1978. 53. Yaxley GA, Jull GA. A modified upper limb tension test: an investigation of responses in normal subjects. Aust J Physiother. 1991;37:143–51. 54. Grant R, Forrester C, Hides J. Screen based keyboard operation: the adverse effects on the neural system. Aust J Physiother. 1995;41(2):99–107. 55. Drye CD. The upper limb tension test 3: An investigation of the intrarater and interrater reliability and the subjective response to the test. Master’s Thesis, MGH Institute of Health Professions; 1993: No. 1351903. 56. Norkin CC, White DJ. Measurement of Joint Motion: A Guide to Goniometry. 2nd ed. Philadelphia, PA: FA Davis Company, 1985. 57. Williams PL, Warwick R (eds). Gray’s Anatomy. 36th ed. Philadelphia: WB Saunders Company, 1980. 58. Portney LG, Watkins MP. Foundations of Clinical Research: Application to Practice. Stamford, CT: Appleton & Lange, 2000. 59. Friberg R, Reeder M, Talley D, Perry T, Ramerez C, Gable C. Symptom distribution for upper limb tension tests 1, 2A, 2B, 3 [abstract PO18]J Orthop Sports Phys Ther. 2000;30(1):A-6. 60. Howard PD. The effect of a radial nerve biased neurodynamic test on shoulder abduction in asymptomatic adults [abstract PL81]. J Orthop Sports Phys Ther. 1999;29(1):A-27. 61. Arking R. The Biology of Aging Observations & Principles. 3rd ed. Oxford, UK: University Press, 2006. 171e174. 62. Goodman CC, Boissonnault WG, Fuller KS. Pathology Implications for the Physical Therapist. 2nd ed. Philadelphia, PA: Saunders, 2003. 1140e1142.

OctobereDecember 2009 353

JHT Read for Credit Quiz: Article # 140

Record your answers on the Return Answer Form found on the tear-out coupon at the back of this issue. There is only one best answer for each question. #1. The authors contend that typically cervical a. UNLT routinely should not be employed in evaluating arm pain b. UNLT should routinely be performed with radial nerve bias rather than ulnar or median nerve bias c. muscular or ligamentous dysfunction is easier to assess than neurodynamic dysfunction d. neurodynamic dysfunction is as easily assessed as muscular or ligamentous dysfunction #2. Radial nerve tensioning can be enhanced by a. lateral bending of the cervical spine to the contralateral side b. lateral bending of the cervical spine to the ipsilateral side c. distraction of the cervical spine d. deep exhalation while making a fist

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#3. Laboratory investigation in rats has shown mechanosensitivity a. in the radial nerve, but not the median or ulnar nerves b. unmylenated peripheral neural tissue c. in A beta and C fibers d. in A delta and C fibers #4. Subjects with þ RB-UNLT also demonstrated loss of a. wrist extension b. shoulder internal rotation c. shoulder abduction d. key pinch #5. The authors declared a conflict of interest that compromises the credibility of the study a. true b. false When submitting to the HTCC for re-certification, please batch your JHT RFC certificates in groups of 3 or more to get full credit.