Background: Inter-individual variability in pharmacological response remains a persistent challenge in clinical rehabilitation. While pharmacokinetic and molecular mechanisms are well established, they account for only a proportion of observed outcome variability. Functional performance, physiological regulation, and behavioral engagement—core domains of physiotherapy—are increasingly recognized as influential determinants of therapeutic response.

Aim: To develop and describe a systemic observational framework integrating physiotherapy-derived functional, physiological, and behavioral indicators with pharmacological response, supported by descriptive statistical reasoning.

Methodology: A conceptual observational methodology was adopted. Peer-reviewed literature was synthesized, and commonly reported trends, proportions, and associations were interpreted using descriptive and inferential statistical logic (e.g., variability, correlation strength, explained variance), without primary data collection.

Results: Evidence across rehabilitation and pharmacological literature consistently indicates that functional and behavioral variables account for a substantial proportion of outcome variability unexplained by pharmacological parameters alone. Descriptive trends suggest moderate-to-strong associations between autonomic regulation, movement efficiency, behavioral engagement, and therapeutic stability.

Conclusion: Incorporating physiotherapy-derived indicators into pharmacological interpretation enhances explanatory power and clinical relevance. A systemic, statistically informed observational framework supports personalized, interdisciplinary healthcare.