Immediate effects of transcutaneous electrical nerve stimulation on gait patterns in chronic stroke survivors: A single group, pretest-posttest clinical trial.

BACKGROUND: Transcutaneous electrical nerve stimulation (TENS) has been used to reduce muscle spasticity and improve locomotion in stroke survivors. We speculate that acute changes in gait performance after TENS mediate functional improvement in the long-term. However, no previous study has investigated the effect of TENS on ankle kinetics and kinematics during walking in stroke survivors. PURPOSE: We aimed to investigate whether TENS applied over the paretic leg could rapidly improve the plantar flexion moment and ankle kinematics in chronic stroke survivors with lower limb paresis. METHODS: Twenty chronic stroke survivors were recruited. They underwent 30 min of TENS over the area innervated by the common peroneal nerve on the paretic leg. Three-dimensional (3D) motion capture was performed and ankle plantar flexor spasticity was assessed before and immediately after stimulation. Ankle kinematics and kinetic and spatiotemporal data were collected using 3D motion capture. Ankle plantar flexor spasticity was assessed using the Modified Tardieu Scale. PRINCIPAL RESULTS: A significant increase in the ankle plantar flexion moment of the paretic side during the pre-swing phase was observed immediately after stimulation (p = 0.009, maximal mean difference = 0.035, 95%CI = 0.0125 to 0.0575). The step length of the paretic limb also increased significantly after stimulation (p = 0.023, mean difference = -0.02, 95%CI = -0.04 to -0.004). TENS had no immediate effect on paretic ankle spasticity, as measured by the Modified Tardieu Scale, or on other temporo-spatial parameters. CONCLUSION: The findings support the use of TENS to improve the motor function and gait pattern in chronic stroke survivors. The study indicated that the application of TENS to the paretic leg before gait training might improve rehabilitation outcomes. Future studies investigating the effects of TENS on functional outcomes, the optimal stimulation duration, and assessing spasticity using more sensitive measures are warranted.

A structural equation model of the relationship between muscle strength, balance performance, walking endurance and community integration in stroke survivors.

PURPOSE: To use structural equation modelling (SEM) to determine (1) the direct and indirect associations of strength of paretic lower limb muscles with the level of community integration, and (2) the direct association of walking endurance and balance performance with the level of community integration in community-dwelling stroke survivors. MATERIALS AND METHODS: In this cross-sectional study of 105 stroke survivors, the Subjective Index of Physical and Social Outcome (SIPSO) was used to measure the level of community integration. Lower-limb strength measures included isometric paretic ankle strength and isokinetic paretic knee peak torque. The Berg Balance Scale (BBS) and the 6-minute walk test (6MWT) were used to evaluate balance performance and walking endurance, respectively. RESULTS: SEM revealed that the distance walked on the 6MWT had the strongest direct association with the SIPSO score (ß = 0.41, p <0.001). An increase of one standard deviation in the 6MWT distance resulted in an increase of 0.41 standard deviations in the SIPSO score. Moreover, dorsiflexion strength (ß = 0.18, p = 0.044) and the BBS score (ß = 0.21, p = 0.021) had direct associations with the SIPSO score. CONCLUSIONS: The results of the proposed model suggest that rehabilitation training of community-dwelling stroke survivors could focus on walking endurance, balance performance and dorsiflexor muscle strengthening if the aim is to augment the level of community integration.