Christina W.Y. Hui-Chan

Functional Electrical Stimulation Improves Motor Recovery of the Lower Extremity and Walking Ability of Subjects With First Acute Stroke. A Randomized Placebo-Controlled Trial

Background and Purpose— The effectiveness of functional electrical stimulation (FES) has been investigated in chronic hemiplegia. The present study examines whether FES, given during acute stroke, was more effective in promoting motor recovery of the lower extremity and walking ability than standard rehabilitation alone. Methods— Forty-six subjects, 70.9±8.0 years old and 9.2±4.1 days after stroke, were assigned randomly to 1 of 3 groups receiving standard rehabilitation with FES or placebo stimulation or alone (control). FES was applied 30 minutes and placebo stimulation 60 minutes, 5 days per week for 3 weeks. Outcome measurements included composite spasticity score, maximum isometric voluntary contraction of ankle dorsi-flexors and planter-flexors, and walking ability. They were recorded before treatment, weekly during the 3-week treatment, and at week 8 after stroke. Results— No significant differences were found in the baseline measurements. After 3 weeks of treatment, there was a significant reduction in the percentage of composite spasticity score, and a significant improvement in the ankle dorsiflexion torque, accompanied by an increase in agonist electromyogram and a reduction in electromyogram cocontraction ratio in the FES group, when compared with the other 2 groups (P<0.05). All subjects in the FES group were able to walk after treatment, and 84.6% of them returned home, in comparison with the placebo (53.3%) and control (46.2%, P<0.05) groups. Conclusions— Fifteen sessions of FES, applied to subjects with acute stroke plus standard rehabilitation, improved their motor and walking ability to the degree that more subjects were able to return to home.

Joint torques during sit-to-stand in healthy subjects and people with Parkinson’s disease

OBJECTIVES To compare lower limb joint torques during sit-to-stand in normal elderly subjects and people with Parkinsons disease, using a developed biomechanical model simulating all phases of sit-to-stand.Design. A cross-sectional study utilizing a Parkinsonian and a control group. BACKGROUND Subjects with Parkinsons disease were observed to experience difficulty in performing sit-to-stand. The developed model was used to calculate the lower limb joint torques in normal elderly subjects and subjects with Parkinsons disease, to delineate possible causes underlying difficulties in initiating sit-to-stand task. METHODS Six normal elderly subjects and seven age-matched subjects with Parkinsons disease performed five sit-to-stand trials at their self-selected speed. Anthropometric data, two-dimensional kinematic and foot-ground and thigh-chair reactive forces were used to calculate, via inverse dynamics, the joint torques during sit-to-stand in both before and after seat-off phases. The difference between the control and Parkinsons disease group was analysed using independent t-tests. RESULTS Both control and Parkinsons disease groups had a similar joint kinematic pattern, although the Parkinsons disease group demonstrated a slower angular displacement. The latter subjects produced significantly smaller normalized hip flexion torque and presented a slower torque build-up rate than the able-bodied subjects (P<0.05). CONCLUSION Slowness of sit-to-stand in people with Parkinsons disease could be due to a reduced hip flexion joint torque and a prolonged rate of torque production.

Balance control in adolescents with idiopathic scoliosis and disturbed somatosensory function.

Study Design. A cross-sectional study of the balance control in adolescents with idiopathic scoliosis. Objective. To investigate the relationship among somatosensory function, balance control, and adolescent idiopathic scoliosis (AIS). Summary of Background Data. Balance control requires the contribution of somatosensory, visual, and vestibular inputs. Previous studies have shown that abnormal somatosensory evoked potentials (SSEPs) were associated with AIS. Methods. A total of 105 girls with AIS and 57 normal girls aged 11–14 years entered the study, and were evaluated with bilateral tibial nerve evoked cerebral SSEPs and standing balance control under reduced or conflicting sensory conditions (i.e., the sensory organization test). One-way analysis of variance was conducted to evaluate the effects of scoliosis and somatosensory function tested by SSEPs on the performance of sensory organization test. Results. There were 15 patients with AIS who had abnormal SSEPs. Postural sway was measured on all subjects under normal, reduced, or conflicting somatosensory, visual, and vestibular conditions. One-way analysis of variance indicated no significant effect of spinal deformity or SSEPs on the balance control when there was an increased reliance on the somatosensory, visual, and vestibular systems during stance (P > 0.05). However, in the patients with abnormal SSEPs, a significant effect was found when subjects had to rely on somatosensory input for their balance control (P = 0.023). The effect of scoliosis by itself was not found to be significant (P = 1.0). Conclusions. The finding of significantly larger difference in bilateral SSEP latencies in patients with AIS indicated the association of abnormal SSEPs with AIS. The finding of a significant effect of SSEPs on the balance control further indicated the presence of abnormal somatosensory function in a subgroup of patients with AIS.

Transcutaneous Electrical Nerve Stimulation Combined With Task-Related Training Improves Lower Limb Functions in Subjects With Chronic Stroke

Background and Purpose— Previous studies have shown that repeated sensory inputs could enhance brain plasticity and cortical motor output. The purpose of this study was to investigate whether combining electrically induced sensory inputs through transcutaneous electrical nerve stimulation (TENS) with task-related training (TRT) in a home-based program would augment voluntary motor output in chronic stroke survivors better than either treatment alone or no treatment. Methods— Eighty-eight patients with stroke were assigned randomly to receive a home-based program of (1) TENS, (2) TENS+TRT, (3) placebo TENS+TRT, or (4) no treatment (control) 5 days a week for 4 weeks. Outcome measurements included Composite Spasticity Scale, peak torques generated during maximum isometric voluntary contraction of ankle dorsiflexors and plantarflexors, and gait velocity recorded at baseline, after 2 and 4 weeks of treatment, and 4 weeks after treatment ended. Results— When compared with TENS, the combined TENS+TRT group showed significantly greater improvement in ankle dorsiflexion torque at follow-up and in ankle plantarflexion torque at week 2 and follow-up (P<0.01). When compared with placebo+TRT, the TENS+TRT group produced earlier and greater reduction of plantarflexor spasticity and improvement in ankle dorsiflexion torque at week 2 (P<0.01). When compared with all 3 groups, the TENS+TRT group showed significantly greater improvement in gait velocity (P<0.01). Conclusions— In patients with chronic stroke, 20 sessions of a combined TENS+TRT home-based program decreased plantarflexor spasticity, improved dorsiflexor and plantarflexor strength, and increased gait velocity significantly more than TENS alone, placebo+TRT, or no treatment. Such improvements can even be maintained 4 weeks after treatment ended.

Ankle Joint Proprioception and Postural Control in Basketball Players With Bilateral Ankle Sprains

Background Deficiencies in ankle proprioception and standing balance in basketball players with multiple ankle sprains have been reported in separate studies. However, the question of how ankle proprioceptive inputs and postural control in stance are related is still unclear. Hypothesis Ankle repositioning errors and the amount of postural sway in stance are increased in basketball players with multiple ankle sprains. Study Design Controlled laboratory study. Methods Twenty healthy male basketball players and 19 male basketball players who had suffered bilateral ankle sprains within the past 2 years were examined. Both groups were similar in age. Passive ankle joint repositioning errors at 5° of plantar flexion were used to test for ankle joint proprioception. The Sensory Organization Test was applied with dynamic posturography to assess postural sway angle under 6 sensory conditions. Results A significant increase in ankle repositioning errors was demonstrated in basketball players with bilateral ankle sprains (P < .05). The mean errors in the right and left ankles were increased from 1.0° (standard deviation, 0.4°) and 0.8° (standard deviation, 0.2°), respectively, in the healthy players to 1.4° (standard deviation, 0.7°) and 1.1° (standard deviation, 0.5°) in the injured group. A significant increase in the amount of postural sway in the injured subjects was also found in conditions 1, 2, and 5 of the Sensory Organization Test (P < .05). Furthermore, there were positive associations between averaged errors in repositioning both ankles and postural sway angles in conditions 1, 2, and 3 of the Sensory Organization Test (r = 0.39-0.54, P < .05). Conclusions Ankle repositioning errors and postural sway in stance increased in basketball players with multiple ankle sprains. A positive relationship was found between these 2 variables. Clinical Relevance Such findings highlight the need for the rehabilitation of patients with multiple ankle sprains to include proprioceptive and balance training.

Optimal stimulation duration of tens in the management of osteoarthritic knee pain.

OBJECTIVE This study examined the optimal stimulation duration of transcutaneous electrical nerve stimulation (TENS) for relieving osteoarthritic knee pain and the duration (as measured by half-life) of post-stimulation analgesia. SUBJECTS Thirty-eight patients received either: (i) 20 minutes (TENS20); (ii) 40 minutes (TENS40); (iii) 60 minutes (TENS60) of TENS; or (iv) 60 minutes of placebo TENS (TENS(PL)) 5 days a week for 2 weeks. METHODS A visual analogue scale recorded the magnitude and pain relief period for up to 10 hours after stimulation. RESULTS By Day10, a significantly greater cumulative reduction in the visual analogue scale scores was found in the TENS40 (83.40%) and TENS60 (68.37%) groups than in the TENS20 (54.59%) and TENS(PL) (6.14%) groups (p < 0.000), such a group difference was maintained in the 2-week follow-up session (p < 0.000). In terms of the duration of post-stimulation analgesia period, the duration for the TENS40 (256 minutes) and TENS60 (258 minutes) groups was more prolonged than in the other 2 groups (TENS20 = 168 minutes, TENS(PL) = 35 minutes) by Day10 (p < 0.000). However, the TENS40 group produced the longest pain relief period by the follow-up session. CONCLUSION 40 minutes is the optimal treatment duration of TENS, in terms of both the magnitude (VAS scores) of pain reduction and the duration of post-stimulation analgesia for knee osetoarthritis.

A randomized clinical trial of TENS and exercise for patients with chronic neck pain

Objective: To investigate the effect of transcutaneous electrical nerve stimulation (TENS) on acupuncture points and neck exercise in chronic neck pain patients. Design: A randomized clinical trial. Setting: Hospital-based practice. Subjects: Two hundred and eighteen patients with chronic neck pain. Interventions: Subjects were randomized into three groups, receiving either (1) TENS over the acupuncture points plus infrared irradiation (TENS group); (2) exercise training plus infrared irradiation (exercise group); or (3) infrared irradiation alone (control); twice a week for six weeks. Outcome measures: The values of verbal numeric pain scale, Northwick Park Neck Pain Questionnaire, and isometric neck muscle strength were assessed before, at the end of the six-week treatment, and at the six-month follow-up. Results: Results demonstrated that after the six-week treatment, significant improvement in the verbal numerical pain scale was found only in the TENS group (0.60±2.54, p=0.027) and the exercise group (1.57±2.67, p<0.001). Though significant reduction in Northwick Park Neck Pain Questionnaire score was found in all three groups, post-hoc tests showed that both the TENS and the exercise group produced better improvement (0.38±0.60% and 0.39±0.62% respectively) than the control group (0.23±0.63%). Significant improvement (p = <0.001 to 0.03) in neck muscle strength was observed in all three groups, however, the improvement in the control group was not clinically significant and it could not be maintained at the six-month follow-up. Conclusions: After the six-week treatment, patients in the TENS and exercise group had a better and clinically relevant improvement in disability, isometric neck muscle strength, and pain. All the improvements in the intervention groups were maintained at the six-month follow-up.

Short-form Tai Chi Improves Standing Balance of People With Chronic Stroke

Background and Objective. Our previous findings showed that 4 weeks of intensive Tai Chi practice improved standing balance in healthy seniors. This study set out to investigate whether Tai Chi could improve standing balance in subjects with chronic stroke. Methods. One hundred thirty-six subjects >6 months after stroke were randomly assigned to a control group (n = 62) practicing general exercises or a Tai Chi group (n = 74) for 12 weeks of training. Each week, 1 hour of group practice was supplemented by 3 hours of self-practice. We used a short-form of Tai Chi consisting of 12 forms that require whole-body movements to be performed in a continuous sequence and demands concentration. A blinded assessor examined subjects at baseline, 6 weeks (mid-program), 12 weeks (end-program), and 18 weeks (follow-up). The 3 outcome measures were (1) dynamic standing balance evaluated by the center of gravity (COG) excursion during self-initiated body leaning in 4 directions, (2) standing equilibrium evaluated in sensory challenged conditions, and (3) functional mobility assessed by Timed-up-and-go score. Mixed model repeated-measures analysis of variance was used to examine between-group differences. Results. When compared with the controls, the Tai Chi group showed greater COG excursion amplitude in leaning forward, backward, and toward the affected and nonaffected sides (P < .05), as well as faster reaction time in moving the COG toward the nonaffected side (P = .014) in the end-program and follow-up assessments. The Tai Chi group also demonstrated better reliance on vestibular integration for balance control at end-program (P = .038). However, neither group improved significantly in Timed-up-and-go scores. Conclusions. Twelve weeks of short-form Tai Chi produced specific standing balance improvements in people with chronic stroke that outlasted training for 6 weeks.

Does four weeks of TENS and/or isometric exercise produce cumulative reduction of osteoarthritic knee pain?

Objective: To evaluate the cumulative effect of repeated transcutaneous electrical nerve stimulation (TENS) on chronic osteoarthritic (OA) knee pain over a four-week treatment period, comparing it to that of placebo stimulation and exercise training given alone or in combination with TENS. Design: Sixty-two patients, aged 50–75, were stratified according to age, gender and body mass ratio before being randomly assigned to four groups. Interventions: Patients received either (1) 60 minutes of TENS, (2) 60 minutes of placebo stimulation, (3) isometric exercise training, or (4) TENS and exercise (TENS & Ex) five days a week for four weeks. Main outcome measures: Visual analogue scale (VAS) was used to measure knee pain intensity before and after each treatment session over a four-week period, and at the four-week follow-up session. Results: Repeated measures ANOVA showed a significant cumulative reduction in the VAS scores across the four treatment sessions (session 1, 10, 20 and the follow-up) in the TENS group (45.9% by session 20, p < 0.001) and the placebo group (43.3% by session 20, p = 0.034). However, linear regression of the daily recordings of the VAS indicated that the slope in the TENS group (slope = -2.415, r = 0.943) was similar to the exercise group (slope = -2.625, r = 0.935), which were steeper than the other two groups. Note that the reduction of OA knee pain was maintained in the TENS group and the TENS & Ex group at the four-week follow-up session, but not in the other two groups. Conclusions: The four treatment protocols did not show significant between-group difference over the study period. It was interesting to note that isometric exercise training of the quadriceps alone also reduced knee pain towards the end of the treatment period.

Does the use of TENS increase the effectiveness of exercise for improving walking after stroke? A randomized controlled clinical trial

Objective: To investigate whether surface electrical stimulation can increase the effectiveness of task-related exercises for improving the walking capacity of patients with chronic stroke. Design: Randomized, placebo-controlled clinical trial. Setting: Home-based programme. Subjects: One hundred and nine hemiparetic stroke survivors were assigned randomly to: (1) transcutaneous electrical nerve stimulation (TENS), (2) TENS + exercise, (3) placebo stimulation + exercise, or (4) control group. Interventions: The TENS group received 60 minutes of electrical stimulation. Both the TENS + exercise group and placebo stimulation + exercise group did 60 minutes of exercises, followed respectively by 60 minutes of electrical and placebo stimulation. Treatment was given five days a week for four weeks. The control group had no active treatment. Outcome measures: Comfortable gait speed was measured using a GAITRite II walkway system. Walking endurance and functional mobility were measured by the distance covered during a 6-minute walk test (6MWT) and by timed up and go test scores before treatment, after two weeks and after four weeks of treatment, and at follow-up four weeks after treatment ended. Results: When compared with the other three groups, only the combined TENS + exercise group showed significantly greater absolute and percentage increases in gait velocity (by 37.1—57.5%, all P<0.01) and reduction in timed up and go scores (by —14.9 to —23.3%, P<0.01) from week 2 onwards. When compared with the control and TENS groups, only the combined TENS + exercise group covered significantly more distance in the 6MWT (by 22.2—34.7%, P<0.01) from week 2 onwards. Conclusion: TENS can improve the effectiveness of task-related exercise for increasing walking capacity in hemiparetic stroke survivors.