Administration of botulinum neurotoxin A (BoNT-A) to the ankle plantar flexors in patients with hemiplegia reduces the strength of knee extension, which may decrease their walking ability. Studies have reported improvements in walking ability with physical therapy following BoNT-A administration. However, no previous studies have evaluated from an exercise physiology perspective the efficacy of physical therapy after BoNT-A administration for adult patients with hemiplegia. To investigate the effects of physical therapy following BoNT-A administration on gait electromyography for patients with hemiparesis secondary to stroke. Non-randomized controlled trial. Single center. Thirty-five patients with chronic stroke with spasticity were assigned to BoNT-A monotherapy (N.=18) or BoNT-A plus physical therapy (PT) (N.=17). On the paralyzed side of the body, 300 single doses of BoNT-A were administered intramuscularly to the ankle plantar flexors. Physical therapy was performed for 2 weeks, starting from the day after administration. Gait electromyography was performed and gait parameters were measured immediately before and 2 weeks after BoNT-A administration. Relative muscle activity, coactivation indices, and walking time/distance were calculated for each phase. For patients who received BoNT-A monotherapy, soleus activity during the loading response decreased 2 weeks after the intervention (P<0.01). For those who received BoNT-A+PT, biceps femoris activity and knee coactivation index during the loading response and tibialis anterior activity during the pre-swing phases increased, whereas soleus and rectus femoris activities during the swing phase decreased 2 weeks after the intervention (P<0.05). These rates of change were significantly greater than those for patients who received BoNT-A monotherapy (P<0.05). Following BoNT-A monotherapy, soleus activity during the stance phase decreased and walking ability either remained unchanged or deteriorated. Following BoNT-A+PT, muscle activity and knee joint stability increased during the stance phase, and abnormal muscle activity during the swing phase was suppressed. If botulinum treatment of the ankle plantar flexors in stroke patients is targeted to those with low knee extension strength, or if it aims to improve leg swing on the paralyzed side of the body, then physical therapy following BoNT-A administration could be an essential part of the treatment strategy.

Abnormal gait, particularly in patients with stroke, causes neuromuscular fatigue. We aimed to clarify temporal changes in gait performance and lower limb muscle activity during extended walking in people with stroke hemiplegia. Twelve adults with stroke and eleven healthy controls performed an extended trial involving 20-min continuous walk at a comfortable speed. The primary outcome was electromyography amplitude during the trial and secondary outcomes were walking performance and the instantaneous mean frequency of electromyography during the trial. Data at 1, 6, 12, and 18 min after initiating walking were compared. Performance during extended walking in people with stroke was maintained over time. The electromyography amplitude decreased in the tibialis anterior during the pre-swing phase and increased in the rectus femoris during the single-support phase over time; these changes were similar on the paretic and nonparetic sides. Instantaneous mean frequency decreased over time on the nonparetic side in the tibialis anterior and on the paretic side in the rectus femoris. Healthy subjects did not show any changes over time. The changes in muscle activity in patients with stroke differed between the paretic and nonparetic sides, muscle type, and gait phase; walking performance was maintained despite being affected by neuromuscular fatigue.

[Purpose] The aim of this study was to clarify the optimal timing for increasing muscle activity in the paralyzed lower limb of stroke survivors by evaluating the relationship between gait muscle activity patterns and gait parameters. [Participants and Methods] Electromyography of the tibialis anterior, soleus, rectus femoris, and biceps femoris on the paralyzed side and spatiotemporal gait parameters were evaluated in 40 chronic post-stroke patients as they walked at a comfortable speed. The normalized average amplitude and asymmetry indexes of each gait phase were calculated. The correlations between gait velocity or asymmetry indexes and the activity amplitudes of various muscles during each gait phase were analyzed. Multiple regression analysis was performed with gait velocity or asymmetry indexes as the response variable and the muscle activity amplitudes in the various gait phases as explanatory variables. [Results] The major determinants of gait velocity were the tibialis anterior activity (β=−0.35) and biceps femoris activity (β=0.45) during the swing phase. In addition, the biceps femoris activity during the swing phase was the major determinant of the asymmetry index for the swing phase duration (β=−0.41). [Conclusion] For patients with hemiparesis, increasing the biceps femoris activity during the swing phase is considered optimal, which may lead to improvement in walking performance.

Age-related decline in lower limb motor control may cause errors in pedal operation when driving a car. This study aimed to clarify the kinematics and electrophysiological characteristics of the pedal-switching operation associated with emergency braking in the case of elderly drivers. The participants in this study consisted of 11 young drivers and 10 elderly drivers. An experimental pedal was used, and the muscle activity and kinematic data during braking action were analyzed using the light from a light-emitting diode installed in the front as a trigger. The results showed that elderly drivers took the same time from viewing the visual stimulus to releasing the accelerator pedal as younger drivers, but took longer to switch to the brake pedal. The elderly drivers had higher soleus muscle activity throughout the process, from accelerator release to brake contact; furthermore, the rectus femoris activity was delayed, and the simultaneous activity between the rectus femoris and biceps femoris was low. Furthermore, elderly drivers tended to have low hip adduction velocity and tended to switch pedals by hip internal rotation. Thus, the alteration in joint movements and muscle activity of elderly drivers can reduce their pedal operability and may be related to the occurrence of pedal errors.