Instrument-assisted Soft Tissue Mobilisation and Myofascial Release Applied to the Hamstrings in Cerebral Palsy: A Critical Narrative Review of Mechanistic Claims, Comparative Evidence and the Untested Link to Sitting Balance

Abstract

Hamstring shortening and increased passive stiffness are among the most consistently reported musculoskeletal impairments in cerebral palsy, and both are commonly assumed to constrain seated postural alignment and sitting balance. Two soft tissue interventions, instrument-assisted soft tissue mobilisation and myofascial release, are increasingly applied to the hamstrings in paediatric neurorehabilitation on the basis of this assumption, and a comparative literature has begun to accumulate. This critical narrative review examines whether that literature supports comparative claims about sitting balance, and, if it does not, what specifically is missing. Searching of scholarly databases and indexes from January 1997 to 20 June 2026, supplemented by citation tracking and registry checking, identified no controlled study in cerebral palsy that used sitting balance or trunk control as an outcome of either intervention. Direct evidence in cerebral palsy is confined to a small number of short trials and case reports addressing hamstring extensibility, passive range and spasticity ratings, with pilot work reporting no between-group separation. Indirect evidence from non-neurological populations is internally inconsistent: instrument-based application improves stretch tolerance and joint angle more reliably than it alters measured tissue stiffness, and remote fascial-chain application has failed to change hamstring extensibility at all. Head-to-head comparisons in other body regions have repeatedly returned equivalence rather than superiority. The review argues that the field has inherited a three-link causal chain, in which tissue treatment alters extensibility, altered extensibility alters pelvic and trunk mechanics, and altered mechanics improve sitting balance, while testing only the first link. Terminological instability, particularly the use of one intervention label for both a manual technique and a surgical procedure, further obscures synthesis. Research priorities are specified for mechanism-appropriate outcome selection, dose reporting, control conditions and trial design in children classified across the full range of gross motor function.