Summary Neuromechanical principles define the properties and problems that shape neural solutions for movement. Although the theoretical and experimental evidence is debated, we present arguments for consistent structures in motor patterns, i.e. motor modules, that are neuromechanical solutions for movement particular to an individual and shaped by evolutionary, developmental, and learning processes. As a consequence, motor modules may be useful in assessing sensorimotor deficits specific to an individual, and define targets for the rational development of novel rehabilitation therapies that enhance neural plasticity and sculpt motor recovery. We propose that motor module organization is disrupted and may be improved by therapy in spinal cord injury, stroke, and Parkinson’s disease. Recent studies provide insights into the yet unknown underlying neural mechanisms of motor modules, motor impairment and motor learning, and may lead to better understanding of the causal nature of modularity and its underlying neural substrates.

Background and Purpose-Functional electrical stimulation (FES) is a popular poststroke gait rehabilitation intervention.Although stroke causes multijoint gait deficits, FES is commonly used only for the correction of swing-phase foot drop. Ankle plantarflexor muscles play an important role during gait. The aim of the current study was to test the immediate effects of delivering FES to both ankle plantarflexors and dorsiflexors on poststroke gait. Methods-Gait analysis was performed as subjects (Nϭ13) with chronic poststroke hemiparesis walked at their self-selected walking speeds during walking with and without FES. Results-Compared with delivering FES to only the ankle dorsiflexor muscles during the swing phase, delivering FES to both the paretic ankle plantarflexors during terminal stance and dorsiflexors during the swing phase provided the advantage of greater swing-phase knee flexion, greater ankle plantarflexion angle at toe-off, and greater forward propulsion. Although FES of both the dorsiflexor and plantarflexor muscles improved swing-phase ankle dorsiflexion compared with noFES, the improvement was less than that observed by stimulating the dorsiflexors alone, suggesting the need to further optimize stimulation parameters and timing for the dorsiflexor muscles during gait. Conclusions-In contrast to the typical FES approach of stimulating ankle dorsiflexor muscles only during the swing phase, delivering FES to both the plantarflexor and dorsiflexor muscles can help to correct poststroke gait deficits at multiple joints (ankle and knee) during both the swing and stance phases of gait. Our study shows the feasibility and advantages of stimulating the ankle plantarflexors during FES for poststroke gait.

OBJECTIVE To determine 1) the feasibility and safety of implementing a 12-week locomotor intervention targeting paretic propulsion deficits during walking through the joining of two independent interventions: walking at maximal speed on a treadmill and functional electrical stimulation of the paretic ankle musculature (FastFES), 2) the effects of FastFES training on individual subjects, and 3) the influence of baseline impairment severity on treatment outcomes. DESIGN A single group pre-post preliminary study investigating a novel locomotor intervention. Changes following treatment were assessed using pair-wise comparisons and compared to known minimal clinically important differences (MCIDs) or minimal detectable changes (MDCs). Correlation analyses were run to determine the relationship between baseline clinical and biomechanical performance versus improvements in walking speed. SETTING University clinical research laboratory. PARTICIPANTS Thirteen individuals with locomotor deficits following a stroke. INTERVENTION FastFES training was provided for 12 weeks at a frequency of 3 sessions per week and 30 minutes per session. MAIN OUTCOME MEASURES Measures of gait mechanics, functional balance, short- and long-distance walking function, and self-perceived participation were collected at baseline, post-training, and at a 3 month follow-up. RESULTS Twelve of the 13 subjects recruited completed training. Improvements in paretic propulsion were accompanied by improvements in functional balance, walking function, and self-perceived participation (each p < 0.02) – all of which were maintained at the 3 month follow up. Eleven of the 12 subjects achieved meaningful functional improvements. Baseline impairment was predictive of absolute, but not relative functional change following training. CONCLUSIONS This report demonstrates the safety and feasibility of the FastFES intervention and supports further study of this promising locomotor intervention for persons post-stroke.