Abstract TP317: Impact of plantarflexor central drive deficits on gait and daily physical activity in sub-acute stroke

Introduction: Walking impairments are a leading cause of long-term disability after stroke. Early, targeted interventions are critical for neuromotor recovery, yet precise treatment targets remain unclear. Deficits in central drive to the paretic plantarflexors (i.e., the percentage of plantarflexor strength capacity accessed during maximum voluntary contraction) are linked to impaired gait propulsion and slow walking speeds in chronic stroke, but are poorly understood in subacute stroke, largely due to lack of clinically accessible assessment tools. To address this, our team developed a mobile system that validly measures plantarflexor central drive in clinical settings. This study evaluates associations between central drive deficits, gait quality, and real-world physical activity in individuals with sub-acute stroke. Hypothesis: We hypothesized that plantarflexor central drive deficits would be associated with impaired gait quality and reduced real-world physical activity. Methods: Six participants with sub-acute stroke (age: 63 ± 12.25 years; stroke onset: 2.41 ± 0.93 months) were enrolled at discharge from inpatient rehabilitation. Physical therapists conducted all assessments. Gait was measured using wearable sensors during the 6-Minute Walk Test to capture stride length, cadence, speed. Central drive was evaluated using a custom-built, portable, neurostimulation-integrated dynamometer. Physical activity was tracked for 7 days using Actigraph monitors to quantify time spent in light (≤3.0 METs) and moderate-to-vigorous (>3.0 METs) activity. Spearman correlations assessed relationships between central drive, gait metrics, and activity levels. Results: Participants had an average central drive of 87.65 ± 14.60% (100%= no impairment). Greater central drive deficits were significantly associated with shorter stride length ( r s =0.943 ; p = 0.005 ) and more time in light activity ( r s = -0.886 ; p = 0.019), but not with moderate-to-vigorous daily physical activity (p > 0.05). No significant associations were found with gait speed or cadence. Conclusions: Preliminary findings support the clinical value of central drive in subacute stroke, revealing strong associations with impaired gait, particularly shorter stride length, and limited engagement in health-promoting moderate-to-vigorous physical activity. Early interventions targeting plantarflexor central drive deficits may improve gait, daily physical activity, and ultimately long-term health after stroke.