Comparative effects of three myofascial release techniques on pectoralis minor tightness: A randomized controlled trial

Abstract

Background: Pectoralis minor (PM) tightness may cause scapular anterior tilting, leading to rounded shoulder posture (RSP). Techniques such as stretching, manual or self-myofascial release (SMR), and instrument-assisted soft tissue mobilization (IASTM) are used to restore PM length. Purpose: The aim of this study was to compare the acute effects of three different myofascial release techniques in asymptomatic individuals with PM tightness. Methods: Thirty-nine subjects were randomized into three groups: the IASTM group, the manual myofascial release (MMR) group, and the SMR group. The PMI index was used to assess PM length and was the primary outcome measure. RSP, glenohumeral (GH) total arc motion, skin temperature and Pressure pain threshold (PPT) were secondary outcome measures. Results: Significant within-group improvements in PMI were observed following IASTM (p = 0.007) and MMR (p = 0.042), whereas no significant change occurred following SMR (p > 0.05). RSP improved significantly in the MMR (p = 0.003) and SMR (p = 0.006) groups. GH total arc motion increased significantly following IASTM and MMR (both p = 0.010). PPT and skin temperature did not change significantly within any group (all p > 0.05). Although post-intervention differences were observed for PMI, GH total arc motion, and skin temperature, change-score comparisons revealed no significant between-group differences for either the primary or secondary outcomes (all p > 0.05). Conclusion: IASTM, MMR, and SMR produced comparable immediate effects in individuals with PM tightness. These findings suggest that all three interventions may be considered viable options for the immediate man agement of PM tightness.