Effects of Instrument Assisted Soft-Tissue Mobilization on Neuromuscular Control for Chronic Ankle Instability

Ankle injuries can cause Chronic Ankle Instability (CAI), causing deficits in ankle mobility and stability. The fibularis longus can have decreased neural excitability associated with CAI. Instrument assisted soft-tissue mobilization (IASTM) is a therapy technique that assists with scar tissue, fascia mobilization, and tissue healing. The objective of our study was to examine the effects of the application of IASTM to the fibularis longus on neuromuscular control (NMC) in individuals with CAI. The independent variables were session (application of IASTM, control) and time (pre- and post-test). The dependent variable was the Y-balance test (YBT) reach distances. We determined if participants had CAI using the ankle instability instrument. IASTM was applied to the fibularis longus muscle for 90 seconds during the intervention, and participants sat for 2 minutes during the control. Pre-test and post-test measurements were taken using the YBT with the best score of 3 trials used for analysis. The interaction between session and time for anterior reach was significant (F1,14=5.256, P=.038, η2=.273). The interaction between session and time was not significant for posteromedial (F1,14=.251, P=.624, η2=.018, 1-β=.075) or posterolateral (F1,14=1.166, P=.298, η2=.077, 1-β=.172) reaches. Our findings suggested that IASTM to the fibularis longus does not immediately improve all aspects of dynamic NMC. The 3.5 cm increase in anterior reach could decrease the risk of non-contact injury if there is asymmetry between injured and uninjured limbs. Keywords: Ankle sprains, Y-balance test, fibularis longus, postural control, manual therap