THE STROKE RECOVERY SIGNATURE: DECODING MUSCLE-SPECIFIC LOWER LIMB STRENGTH GAINS AFTER TASK-ORIENTED TRAINING IN CHRONIC STROKE SURVIVORS

Abstract

Background: Stroke is a leading cause of long-term disability, often resulting in persistent lower limb weakness and impaired functional mobility. While task-oriented training (TOT) is known to improve functional outcomes, muscle-specific strength recovery patterns following TOT remain poorly understood. Objective: To investigate muscle-specific lower limb strength gains following task-oriented training in individuals with chronic stroke. Methods: A pre–post experimental study was conducted on chronic stroke survivors. Participants underwent a structured task-oriented training protocol including sit-to-stand, forward step-up, and side step-up activities. Lower limb muscle strength of both affected and non-affected limbs was measured using a Hand-Held Dynamometer (HHD). Muscles assessed included hip flexors, extensors, abductors, knee flexors, knee extensors, and plantarflexors. Effect sizes and statistical significance were calculated to determine strength improvements. Results: Significant bilateral muscle strength improvements were observed (p < 0.05). In the affected limb, the greatest improvements were seen in ankle plantarflexors (ES = 1.50), hip extensors (ES = 1.46), knee flexors (ES = 1.30), and hip flexors (ES = 1.27). Knee extensors (ES = 1.02) and hip abductors (ES = 0.80) showed comparatively smaller gains. In the non-affected limb, hip flexors and knee flexors demonstrated the highest improvements (ES = 1.60 and 1.60 respectively), indicating bilateral neuromuscular adaptation. Conclusion: Task-oriented training produces significant, muscle-specific bilateral strength gains in chronic stroke survivors. Proximal muscles demonstrate greater adaptive responses, suggesting the need for targeted, muscle-specific rehabilitation strategies.