Mechanobiological and Neurophysiological Effects of Instrument-Assisted Soft Tissue Mobilization: A Narrative Review and Conceptual Framework

Background: Instrument-assisted soft tissue mobilization (IASTM), including scraping-based techniques, is widely applied in musculoskeletal and sports rehabilitation. Despite its extensive clinical use, uncertainty remains regarding its primary mechanisms of action. Traditional explanations have often emphasized macroscopic tissue disruption or the breakdown of adhesions; however, emerging evidence from mechanobiology and pain science challenges these assumptions and suggests alternative mechanisms. Objective: To synthesize current evidence on the mechanobiological and neurophysiological mechanisms underlying IASTM and to propose a conceptual framework linking mechanical input, biological responses, and clinically observable effects relevant to rehabilitation practice. Methods: A narrative review was conducted using PubMed, Scopus, and Web of Science databases, including literature available up to January 2026. Experimental, clinical, and review studies examining IASTM, scraping-based interventions, mechanotransduction, fascia, and neurophysiological modulation were included. Emphasis was placed on mechanistic plausibility, consistency of findings, and relevance to musculoskeletal rehabilitation. Conceptual evidence from related fields was considered when direct IASTM-specific data were limited. Results: The available evidence suggests that the primary effects of IASTM are mediated through mechanotransduction pathways and neurophysiological modulation rather than through structural tissue disruption. Mechanical loading applied during IASTM appears sufficient to influence cellular signaling, local fluid dynamics, pain perception, and sensory processing. Clinically, these mechanisms are associated with modest short-term improvements in pain sensitivity, range of motion, and movement readiness. Evidence supporting long-term structural tissue remodeling or sustained functional change remains limited and inconsistent. Conclusion: IASTM is best conceptualized as a mechanobiological and neuromodulatory intervention that creates a temporary clinical window facilitating active, movement-based rehabilitation rather than as a standalone tissue-altering treatment. Future research should prioritize standardized dosing parameters, mechanistic outcome measures, and long-term functional effects to clarify its role within contemporary rehabilitation models.