Neuromechanical basis of region-specific differences and their implications for sport performance and injury prevention: a narrative review

This review aims to summarize current knowledge on regional variations in muscle structure and neural organization. It also examines how these differences affect muscle function and explores the current evidence for region-specific neuromuscular adaptations to training and injury/unloading in humans. Muscles exhibit substantial structural and functional heterogeneity along their length, reflected by regional variations in architecture, fiber type composition, sarcomere lengths, and tendon-aponeurosis structure. These differences potentially underpin distinct regional capacities for force production, contraction velocity, and energy storage. Additionally, compartmentalization within the neuromuscular system, characterized by spatially differentiated motor unit territories and region-specific activation, potentially allowing for specialized muscle function across varying tasks. However, current evidence predominantly relies on descriptive or animal studies, limiting direct translation into human-specific practices. Although preliminary findings suggest that region-specific adaptations occur following training, injury, or unloading, the practical implications for performance optimization or injury prevention remain speculative. Therefore, future longitudinal studies in humans are required to elucidate the functional relevance of these regional neuromuscular differences, to establish clearer mechanistic insights, and to determine whether such knowledge can guide training interventions and rehabilitation protocols to enhance performance and reduce injury risk.