Rehabilitation of gait speed after stroke: a critical review of intervention approaches

Efficacy of Functional Strength Training on Restoration of Lower-Limb Motor Function Early After Stroke: Phase I Randomized Controlled Trial

After stroke, physiotherapy can promote brain reorganization and motor recovery. Combining muscle strength and functional training (functional strength training, FST) may be beneficial. The aim of the authors was to compare FST with conventional physiotherapy (CPT) while controlling for the potential confounder of therapy intensity in a multicenter, randomized controlled observer-blind trial. The mean age of the participants was 68.3 (standard deviation [SD] = 12.03) years at a mean of 34 (SD = 20) days after stroke, with mean peak paretic knee extension torque (torque) of 22 (SD = 25) Nm. The estimated sample size was 102 to detect a between-group difference of 0.2 m/s in walking speed. After baseline measures, participants were allocated randomly to CPT or CPT + CPT or CPT + FST for 6 weeks. Additional experimental therapy was provided for up to 1 hour a day, 4 times each week. Outcomes were measured 6 weeks after baseline and at follow-up 12 weeks thereafter. Measures included walking speed, knee extensor torque, and functional mobility (Rivermead). At outcome, both extraintensity groups showed greater increases in walking speed than the CPT group, but this reached significance only for the CPT + CPT group ( P = .031). The CPT + CPT group also had a greater number of participants who walked at 0.8 m/s or above. No significant differences were observed for torque about the knee or for the Rivermead score. At follow-up, no significant differences were observed. These phase I results justify a subsequent trial of CPT + CPT versus CPT + FST.

Progressive Staging of Pilot Studies to Improve Phase III Trials for Motor Interventions

Based on the suboptimal research pathways that finally led to multicenter randomized clinical trials (MRCTs) of treadmill training with partial body weight support and of robotic assistive devices, strategically planned successive stages are proposed for pilot studies of novel rehabilitation interventions. Stage 1, consideration-of-concept studies, drawn from animal experiments, theories, and observations, delineate the experimental intervention in a small convenience sample of participants, so the results must be interpreted with caution. Stage 2, development-of-concept pilots, should optimize the components of the intervention, settle on most appropriate outcome measures, and examine dose-response effects. A well-designed study that reveals no efficacy should be published to counterweight the confirmation bias of positive trials. Stage 3, demonstration-of-concept pilots, can build out from what has been learned to test at least 15 participants in each arm, using random assignment and blinded outcome measures. A control group should receive an active practice intervention aimed at the same primary outcome. A third arm could receive a substantially larger dose of the experimental therapy or a combinational intervention. If only 1 site performed this trial, a different investigative group should aim to reproduce positive outcomes based on the optimal dose of motor training. Stage 3 studies ought to suggest an effect size of 0.4 or higher, so that approximately 50 participants in each arm will be the number required to test for efficacy in a stage 4, proof-of-concept MRCT. By developing a consensus around acceptable and necessary practices for each stage, similar to CONSORT recommendations for the publication of phase III clinical trials, better quality pilot studies may move quickly into better designed and more successful MRCTs of experimental interventions.

The Relationships Between the Unified Parkinson’s Disease Rating Scale and Lower Extremity Functional Performance in Persons With Early-Stage Parkinson’s Disease

Background. The Unified Parkinson’s Disease Rating Scale (UPDRS) is the “gold standard” assessment tool for characterizing impairments in persons with Parkinson’s disease (PD); however, this scale’s ability to predict functional capabilities across different functional tasks has not been adequately assessed in persons with early-stage PD. Methods. Thirty persons with PD within 3 years of diagnosis and without motor fluctuation performed self-selected walking, fast walking, and sit-to-stand and stair-climbing tasks. Pearson’s correlation coefficients were used to calculate correlations with a standard UPDRS examination ( P < .05). Simple linear regression models were used to fit each functional performance outcome measure with the UPDRS total predictor scores. Results. The correlations between the UPDRS motor (section III), UPDRS total scores, and all timed functional performance measures were fair to good (range, 0.45-0.57). Conversely, only greater self-selected time to walk 50 ft correlated with a higher UPDRS activities of daily living (II) score ( r = .386; P < .05). Conclusions. The UPDRS motor (III) and total scores may be good predictors of overall lower extremity function in persons with early-stage PD. Understanding the relationships between UPDRS scores and functional capabilities may allow clinicians to better quantify early physical functioning, longitudinally assess disease progression, and assess the efficacy of interventions.

Community-based adaptive physical activity program for chronic stroke: feasibility, safety, and efficacy of the Empoli model

OBJECTIVE

To determine whether Adaptive Physical Activity (APA-stroke), a community-based exercise program for participants with hemiparetic stroke, improves function in the community.

METHODS

Nonrandomized controlled study in Tuscany, Italy, of participants with mild to moderate hemiparesis at least 9 months after stroke. Forty-nine participants in a geographic health authority (Empoli) were offered APA-stroke (40 completed the study). Forty-four control participants in neighboring health authorities (Florence and Pisa) received usual care (38 completed the study). The APA intervention was a community-based progressive group exercise regimen that included walking, strength, and balance training for 1 hour, thrice a week, in local gyms, supervised by gym instructors. No serious adverse clinical events occurred during the exercise intervention. Outcome measures included the following: 6-month change in gait velocity (6-Minute Timed Walk), Short Physical Performance Battery (SPPB), Berg Balance Scale, Stroke Impact Scale (SIS), Barthel Index, Hamilton Rating Scale for Depression, and Index of Caregivers Strain.

RESULTS

After 6 months, the intervention group improved whereas controls declined in gait velocity, balance, SPPB, and SIS social participation domains. These between-group comparisons were statistically significant at P<.00015. Individuals with depressive symptoms at baseline improved whereas controls were unchanged (P<.003). Oral glucose tolerance tests were performed on a subset of participants in the intervention group. For these individuals, insulin secretion declined 29% after 6 months (P=.01).

CONCLUSION

APA-stroke appears to be safe, feasible, and efficacious in a community setting.

Split-belt treadmill adaptation transfers to overground walking in persons poststroke

BACKGROUND AND OBJECTIVE

Following stroke, subjects retain the ability to adapt interlimb symmetry on the split-belt treadmill. Critical to advancing our understanding of locomotor adaptation and its usefulness in rehabilitation is discerning whether adaptive effects observed on a treadmill transfer to walking over ground. We examined whether aftereffects following split-belt treadmill adaptation transfer to overground walking in healthy persons and those poststroke.

METHODS

Eleven poststroke and 11 age-matched and gender-matched healthy subjects walked over ground before and after walking on a split-belt treadmill. Adaptation and aftereffects in step length and double support time were calculated.

RESULTS

Both groups demonstrated partial transfer of the aftereffects observed on the treadmill (P<.001) to overground walking (P<.05), but the transfer was more robust in the subjects poststroke (P<.05). The subjects with baseline asymmetry after stroke improved in asymmetry of step length and double limb support (P=.06).

CONCLUSIONS

The partial transfer of aftereffects to overground walking suggests that some shared neural circuits that control locomotion for different environmental contexts are adapted during split-belt treadmill walking. The larger adaptation transfer from the treadmill to overground walking in the stroke survivors may be due to difficulty adjusting their walking pattern to changing environmental demands. Such difficulties with context switching have been considered detrimental to function poststroke. However, we propose that the persistence of improved symmetry when changing context to overground walking could be used to advantage in poststroke rehabilitation.