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Endurance deficits in patients with Achilles tendinopathy versus healthy controls
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WCPT Congress 2015 / Physiotherapy 2015; Volume 101, Supplement 1 eS833–eS1237
Research Report Poster Presentation Number: RR-PO-99-19-Sun Sunday 3 May 2015 12:15 Exhibit halls 401–403 FREQUENCY ANALYSIS OF ELECTROMYOGRAM OF THE TRICEPS SURAE MUSCLE TAKEN WHILE THE STROKE PATIENTS WALK T. Omori 1 , H. Takebayashi 2 , M. Tomioka 1 , S. Saiki 1 , O. Yamasaki 1 , K. Okada 1 1 Matsuyama
Rehabilitation Hospital, Rehabilitation, Ehime, Japan; 2 Tosa Rehabilitation College, Physical Therapy, Kochi, Japan Background: Many groups have reported results of frequency analysis of electromyogram (EMG) while the muscle with spasticity contracts in stroke patients. However, very few reports on characteristics of the muscle with spasticity during exercise have been published, and the majority is static evaluation using Fast Fourier Transform (FFT). Purpose: We carried out and examined dynamic frequency characteristics of contraction characteristics of the triceps surae while the stroke patients walk using Wavelet Transform (WT) which analyzes temporal information and frequency information of conventional FFT at same time. Methods: Subject of the present study was nine healthy men (age 28.0 ± 2.83), healthy group (HG), and nine stroke patients (age 70.17 ± 9.38), stroke group (SG), who were in the recovery stage and the rehabilitation ward of our hospital. These patients have their hemiplegia after stroke, and can walk by themselves or while being supervised. We measured the dominant feet of the HG and the paralyzed legs of the SG. Surface EMG monitored muscle activation while the subjects freely walked 10 m on a walkway at the optimum speed. Also, a foot switch sensor was attached on the plantar part to identify a single walking cycle. EMG Master (Ozawa Medical Instruments) was used for surface EMG to monitor medial and lateral heads of gastrocnemius muscle. The data after fourth steps from walking starts were analyzed. Integral EMG analysis and wavelet transform (12.5 Hz to 200 Hz) were carried out to any given data of three walking cycles. Calculated integrated values of both groups were normalized using the integrated values during a single walking cycle. Also, the frequency range was divided into two categories; a low-frequency band (LFB) of 45 Hz and lower and highfrequency band of 75 Hz and higher (HFB) to calculate the power density of HFB to LFB, H/L ratio, of each muscle. As a statistical analysis, the Wilcoxon signed-rank test was used to compare the integrated values and H/L ratio between the HG and SG. Results: Each evaluation item of the HG and SG was compared. The HG has a significantly high integrated value (p < 0.05), and the SG has significantly high H/L ratio (p < 0.05).
Conclusion(s): Although muscle activity characteristics of the triceps surae of the stroke patients is low as an integrated value, the ratio of HFB is high as dynamic frequency characteristics. This indicates strong activity of fast fibers. By taking the facts of low integrated value and atrophy of the presence of fast-twitch fibers into account, synchronization defect in the motor units possibly caused a frequency rise. Implications: These findings are expected to help treatment to improve quality of muscle activity in rehabilitation for stroke patients to walk. Keywords: Stroke; Electromyogram; Walking Funding acknowledgements: We with to thanks Ozawa Medical Instruments for their helpful support. Ethics approval: This study was approved by the ethics committee of Matsuyama Rehabilitation Hospital. http://dx.doi.org/10.1016/j.physio.2015.03.2050 Research Report Poster Presentation Number: RR-PO-21-21-Sat Saturday 2 May 2015 12:15 Exhibit halls 401–403 ENDURANCE DEFICITS IN PATIENTS WITH ACHILLES TENDINOPATHY VERSUS HEALTHY CONTROLS S. O’Neill 1 , P. Watson 2 , S. Barry 3 1 University
of Leicester, Medical and Social Care Education, Leicester, United Kingdom; 2 University of Leicester, Health Sciences, Leicester, United Kingdom; 3 Coventry University, Department of Applied Sciences and Health, Coventry, United Kingdom Background: Prospective risk factors for Achilles tendinopathy include strength of the Plantarflexors and endurance has been hypothesised to be involved. Endurance activities are associated with the highest prevalence rates, up to 50% of specific populations. Currently no data exists on endurance capacity in people with Achilles tendinopathy. Endurance is the ability of muscles to sustain power output for long periods of time without fatiguing; this capacity may directly influence the muscles ability to shock absorb for the tendon. Purpose: To determine whether Plantarflexor endurance is affected by Achilles tendinopathy and whether this affect is unilateral or bilateral. Methods: 28 endurance runners with Achilles tendinopathy and 24 endurance runners without a history of Achilles tendinopathy (control group) participated in this study. Achilles tendinopathy was diagnosed on a clinical and ultrasonographic examination. Participants were excluded if they had insertional tendinopathy, bilateral tendinopathy or a clinical history and/or ultrasound scan/diagnosis suggestive of partial rupture. The control group were age, sex, leg and activity matched to the Achilles tendinopathy group.
WCPT Congress 2015 / Physiotherapy 2015; Volume 101, Supplement 1 eS833–eS1237
Plantarflexor muscle endurance was measured during concentric–eccentric muscle contractions at 90◦ /sec over 20 repetitions using a Humac Norm Isokinetic dynamometer. Testing utilised an 80◦ knee flexed position as this significantly inhibits Gastrocnemius thereby testing the function of Soleus, which is the endurance muscle. Previous work has already shown that Soleus is most affected by tendinopathy. Total work done was used to measure endurance capacity as it has been shown to be the most reliable measure. Results: Participants with tendinopathy had a mean total work done of 1313 NM on the symptomatic side and 1490 NM on the non-symptomatic side, whilst controls had a mean of 1900 NM. This data clearly shows that those with tendinopathy have a lower endurance than healthy age, sex and activity matched controls. Independent t tests show a clear statistical difference between the symptomatic leg and healthy controls (p = 0.001) and between the non-symptomatic leg and healthy controls (p = 0.006). There was a significant difference between symptomatic and non-symptomatic legs in participants with disease (p = 0.009). Conclusion(s): Runners with Achilles tendinopathy have less Plantarflexor endurance capacity compared to those without tendinopathy. These differences are bilateral and may be associated with central nervous system changes or may be pre-existing weakness. Further research needs to ascertain whether these differences are pre-existing and lead to tendinopathy or are a direct result of tendinopathy. Future prospective risk factor studies need to incorporate Plantarflexor endurance in addition to strength parameters so that a more comprehensive understanding of neuromuscular factors can be developed. Implications: Endurance is affected by tendinopathy and as such conservative management (Physiotherapy) needs to fully resolve these deficits. This research highlights that the contralateral limb should not be used as a “normal” measure of endurance and that further studies need to use healthy control data. Keywords: Achilles;. Tendinopathy; Tendinitis Funding acknowledgements: No funding was provided for this study. Ethics approval: Ethics approval was provided by the University of Leicester ethics committee. http://dx.doi.org/10.1016/j.physio.2015.03.2051
eS1143
Research Report Poster Presentation Number: RR-PO-21-22-Sun Sunday 3 May 2015 13:00 Exhibit halls 401–403 ECCENTRIC REHABILITATION FOR RUNNERS WITH ACHILLES TENDINOPATHY IMPROVES ENDURANCE CAPACITY OF THE PLANTARFLEXORS S. O’Neill 1 , P. Watson 2 , S. Barry 3 1 University
of Leicester, Medical and Social Care Education, Leicester, United Kingdom; 2 University of Leicester, Health Sciences, Leicester, United Kingdom; 3 Coventry University, Department of Applied Sciences and Health, Coventry, United Kingdom Background: Our previous work has highlighted that runners with Achilles tendinopathy have lowered Plantarflexor endurance capacity compared to healthy controls. It is currently unknown how common tendinopathy rehabilitation protocols alter this deficit in endurance capacity. Purpose: To determine how an eccentric rehabilitation protocol alters Plantarflexor endurance capacity in participants with Achilles tendinopathy. Methods: 20 endurance runners with Achilles tendinopathy were recruited and underwent an eccentric rehabilitation program based on Alfredson’s regime. Achilles tendinopathy was diagnosed on clinical and ultrasonographic examination. Inclusion criteria were – symptoms for 3 months or more. Participants were excluded if they had insertional tendinopathy, bilateral tendinopathy or a clinical history and/or ultrasound diagnosis suggestive of partial rupture. A control group of 24 healthy endurance runners was used from a previous study. These participants were age, sex, leg and activity matched to the Achilles tendinopathy group. Plantarflexor muscle endurance was measured during concentric and eccentric muscle contractions at 90◦ /sec over 20 repetitions using a Humac Norm Isokinetic dynamometer. This testing protocol has been shown to be reliable. Endurance can be measured using “total work done”, “fatigue index” or “endurance ratio”, but previous work has identified that “total work done” measured in Newton Metres (NM) is the most reliable measure. Participants with Achilles tendinopathy were tested at baseline and after 12 weeks of an eccentric exercise regime whilst the control group were only tested at one time point. Results: At baseline participants with tendinopathy had a mean total work done of 1168 NM on the symptomatic side and 1350 NM on the non-symptomatic side, whilst healthy controls had a mean of 1900 NM. After completion of the intervention protocol the symptomatic leg increased to 1618 NM whilst the non-symptomatic leg increased to 1763 NM. The intervention significantly increased endurance capacity of the symptomatic and non-symptomatic legs (p ≥ 0.001).
WCPT Congress 2015 / Physiotherapy 2015; Volume 101, Supplement 1 eS833–eS1237
Research Report Poster Presentation Number: RR-PO-99-19-Sun Sunday 3 May 2015 12:15 Exhibit halls 401–403 FREQUENCY ANALYSIS OF ELECTROMYOGRAM OF THE TRICEPS SURAE MUSCLE TAKEN WHILE THE STROKE PATIENTS WALK T. Omori 1 , H. Takebayashi 2 , M. Tomioka 1 , S. Saiki 1 , O. Yamasaki 1 , K. Okada 1 1 Matsuyama
Rehabilitation Hospital, Rehabilitation, Ehime, Japan; 2 Tosa Rehabilitation College, Physical Therapy, Kochi, Japan Background: Many groups have reported results of frequency analysis of electromyogram (EMG) while the muscle with spasticity contracts in stroke patients. However, very few reports on characteristics of the muscle with spasticity during exercise have been published, and the majority is static evaluation using Fast Fourier Transform (FFT). Purpose: We carried out and examined dynamic frequency characteristics of contraction characteristics of the triceps surae while the stroke patients walk using Wavelet Transform (WT) which analyzes temporal information and frequency information of conventional FFT at same time. Methods: Subject of the present study was nine healthy men (age 28.0 ± 2.83), healthy group (HG), and nine stroke patients (age 70.17 ± 9.38), stroke group (SG), who were in the recovery stage and the rehabilitation ward of our hospital. These patients have their hemiplegia after stroke, and can walk by themselves or while being supervised. We measured the dominant feet of the HG and the paralyzed legs of the SG. Surface EMG monitored muscle activation while the subjects freely walked 10 m on a walkway at the optimum speed. Also, a foot switch sensor was attached on the plantar part to identify a single walking cycle. EMG Master (Ozawa Medical Instruments) was used for surface EMG to monitor medial and lateral heads of gastrocnemius muscle. The data after fourth steps from walking starts were analyzed. Integral EMG analysis and wavelet transform (12.5 Hz to 200 Hz) were carried out to any given data of three walking cycles. Calculated integrated values of both groups were normalized using the integrated values during a single walking cycle. Also, the frequency range was divided into two categories; a low-frequency band (LFB) of 45 Hz and lower and highfrequency band of 75 Hz and higher (HFB) to calculate the power density of HFB to LFB, H/L ratio, of each muscle. As a statistical analysis, the Wilcoxon signed-rank test was used to compare the integrated values and H/L ratio between the HG and SG. Results: Each evaluation item of the HG and SG was compared. The HG has a significantly high integrated value (p < 0.05), and the SG has significantly high H/L ratio (p < 0.05).
Conclusion(s): Although muscle activity characteristics of the triceps surae of the stroke patients is low as an integrated value, the ratio of HFB is high as dynamic frequency characteristics. This indicates strong activity of fast fibers. By taking the facts of low integrated value and atrophy of the presence of fast-twitch fibers into account, synchronization defect in the motor units possibly caused a frequency rise. Implications: These findings are expected to help treatment to improve quality of muscle activity in rehabilitation for stroke patients to walk. Keywords: Stroke; Electromyogram; Walking Funding acknowledgements: We with to thanks Ozawa Medical Instruments for their helpful support. Ethics approval: This study was approved by the ethics committee of Matsuyama Rehabilitation Hospital. http://dx.doi.org/10.1016/j.physio.2015.03.2050 Research Report Poster Presentation Number: RR-PO-21-21-Sat Saturday 2 May 2015 12:15 Exhibit halls 401–403 ENDURANCE DEFICITS IN PATIENTS WITH ACHILLES TENDINOPATHY VERSUS HEALTHY CONTROLS S. O’Neill 1 , P. Watson 2 , S. Barry 3 1 University
of Leicester, Medical and Social Care Education, Leicester, United Kingdom; 2 University of Leicester, Health Sciences, Leicester, United Kingdom; 3 Coventry University, Department of Applied Sciences and Health, Coventry, United Kingdom Background: Prospective risk factors for Achilles tendinopathy include strength of the Plantarflexors and endurance has been hypothesised to be involved. Endurance activities are associated with the highest prevalence rates, up to 50% of specific populations. Currently no data exists on endurance capacity in people with Achilles tendinopathy. Endurance is the ability of muscles to sustain power output for long periods of time without fatiguing; this capacity may directly influence the muscles ability to shock absorb for the tendon. Purpose: To determine whether Plantarflexor endurance is affected by Achilles tendinopathy and whether this affect is unilateral or bilateral. Methods: 28 endurance runners with Achilles tendinopathy and 24 endurance runners without a history of Achilles tendinopathy (control group) participated in this study. Achilles tendinopathy was diagnosed on a clinical and ultrasonographic examination. Participants were excluded if they had insertional tendinopathy, bilateral tendinopathy or a clinical history and/or ultrasound scan/diagnosis suggestive of partial rupture. The control group were age, sex, leg and activity matched to the Achilles tendinopathy group.
WCPT Congress 2015 / Physiotherapy 2015; Volume 101, Supplement 1 eS833–eS1237
Plantarflexor muscle endurance was measured during concentric–eccentric muscle contractions at 90◦ /sec over 20 repetitions using a Humac Norm Isokinetic dynamometer. Testing utilised an 80◦ knee flexed position as this significantly inhibits Gastrocnemius thereby testing the function of Soleus, which is the endurance muscle. Previous work has already shown that Soleus is most affected by tendinopathy. Total work done was used to measure endurance capacity as it has been shown to be the most reliable measure. Results: Participants with tendinopathy had a mean total work done of 1313 NM on the symptomatic side and 1490 NM on the non-symptomatic side, whilst controls had a mean of 1900 NM. This data clearly shows that those with tendinopathy have a lower endurance than healthy age, sex and activity matched controls. Independent t tests show a clear statistical difference between the symptomatic leg and healthy controls (p = 0.001) and between the non-symptomatic leg and healthy controls (p = 0.006). There was a significant difference between symptomatic and non-symptomatic legs in participants with disease (p = 0.009). Conclusion(s): Runners with Achilles tendinopathy have less Plantarflexor endurance capacity compared to those without tendinopathy. These differences are bilateral and may be associated with central nervous system changes or may be pre-existing weakness. Further research needs to ascertain whether these differences are pre-existing and lead to tendinopathy or are a direct result of tendinopathy. Future prospective risk factor studies need to incorporate Plantarflexor endurance in addition to strength parameters so that a more comprehensive understanding of neuromuscular factors can be developed. Implications: Endurance is affected by tendinopathy and as such conservative management (Physiotherapy) needs to fully resolve these deficits. This research highlights that the contralateral limb should not be used as a “normal” measure of endurance and that further studies need to use healthy control data. Keywords: Achilles;. Tendinopathy; Tendinitis Funding acknowledgements: No funding was provided for this study. Ethics approval: Ethics approval was provided by the University of Leicester ethics committee. http://dx.doi.org/10.1016/j.physio.2015.03.2051
eS1143
Research Report Poster Presentation Number: RR-PO-21-22-Sun Sunday 3 May 2015 13:00 Exhibit halls 401–403 ECCENTRIC REHABILITATION FOR RUNNERS WITH ACHILLES TENDINOPATHY IMPROVES ENDURANCE CAPACITY OF THE PLANTARFLEXORS S. O’Neill 1 , P. Watson 2 , S. Barry 3 1 University
of Leicester, Medical and Social Care Education, Leicester, United Kingdom; 2 University of Leicester, Health Sciences, Leicester, United Kingdom; 3 Coventry University, Department of Applied Sciences and Health, Coventry, United Kingdom Background: Our previous work has highlighted that runners with Achilles tendinopathy have lowered Plantarflexor endurance capacity compared to healthy controls. It is currently unknown how common tendinopathy rehabilitation protocols alter this deficit in endurance capacity. Purpose: To determine how an eccentric rehabilitation protocol alters Plantarflexor endurance capacity in participants with Achilles tendinopathy. Methods: 20 endurance runners with Achilles tendinopathy were recruited and underwent an eccentric rehabilitation program based on Alfredson’s regime. Achilles tendinopathy was diagnosed on clinical and ultrasonographic examination. Inclusion criteria were – symptoms for 3 months or more. Participants were excluded if they had insertional tendinopathy, bilateral tendinopathy or a clinical history and/or ultrasound diagnosis suggestive of partial rupture. A control group of 24 healthy endurance runners was used from a previous study. These participants were age, sex, leg and activity matched to the Achilles tendinopathy group. Plantarflexor muscle endurance was measured during concentric and eccentric muscle contractions at 90◦ /sec over 20 repetitions using a Humac Norm Isokinetic dynamometer. This testing protocol has been shown to be reliable. Endurance can be measured using “total work done”, “fatigue index” or “endurance ratio”, but previous work has identified that “total work done” measured in Newton Metres (NM) is the most reliable measure. Participants with Achilles tendinopathy were tested at baseline and after 12 weeks of an eccentric exercise regime whilst the control group were only tested at one time point. Results: At baseline participants with tendinopathy had a mean total work done of 1168 NM on the symptomatic side and 1350 NM on the non-symptomatic side, whilst healthy controls had a mean of 1900 NM. After completion of the intervention protocol the symptomatic leg increased to 1618 NM whilst the non-symptomatic leg increased to 1763 NM. The intervention significantly increased endurance capacity of the symptomatic and non-symptomatic legs (p ≥ 0.001).