Entropy-based analysis of kinetic and kinematic alterations in musculoskeletal pain: A scoping review

Objective To map how entropy-based measures have been applied to kinetic and kinematic signals in individuals with musculoskeletal pain, and to summarize patterns in entropy changes across task contexts. Methods A PRISMA-ScR scoping review was conducted across eight databases from inception to 2 August 2025. Peer-reviewed studies applying entropy metrics to biomechanical signals during motor tasks in adults with musculoskeletal pain were included. Data were charted using the Population–Concept–Context framework, and methodological quality was appraised with the Newcastle–Ottawa Scale adapted for cross-sectional studies (NOS-xs). Results Eighteen studies (n=808; 428 pain, 380 controls) met eligibility criteria. Postural-control tasks (6 studies) predominantly showed lower entropy (more regular sway) in pain groups (5/6). Functional tasks (12 studies) showed mixed directions: lower entropy (5), higher entropy (5), and mixed or non-significant findings (2). Sample entropy and approximate entropy were the most frequently used metrics; multiscale entropy was rarely applied. Conclusion Entropy-based metrics detect alterations in movement regularity in musculoskeletal pain, but the direction of change depends on the condition, task demands, and analytic choices. More consistent reporting of entropy parameters is needed to support comparison and translation.