What question did this study set out to answer?

This study aims to examine how different shoulder abduction angles affect force production and muscle activity during isometric bench pressing.

July 10, 2026Open Access

Impact of shoulder abduction angle on peak force and myoelectric activity during maximal isometric bench press in resistance-trained men

Key Points

This study aims to examine how different shoulder abduction angles affect force production and muscle activity during isometric bench pressing.
Quasi-experimental, within-subject design with twelve resistance-trained men
Measured peak force and sEMG during maximal isometric bench press at 45° and 90° shoulder abduction positions
Statistical analyses conducted using paired t-tests for peak force and two-way ANOVA for sEMG.
No significant difference in peak force was found between 45° and 90° shoulder abduction positions.
Significant differences in muscle activation observed: AD vs. UPM (Δ% = 41.5%), AD vs. LPM (Δ% = 65.4%), UPM vs. LPM (Δ% = 40.8%) at 45°; AD vs. LPM (Δ% = 61.9%) and UPM vs. LPM (Δ% = 41.2%) at 90°.

Abstract

The purpose of this study was to investigate the in uence of shoulder abduction positions (45 vs. 90) on peak force (PF) production and myoelectric activity (sEMG) of the upper and lower pectoralis major (UPM, LPM), anterior deltoid (AD), and long head of the triceps brachii (TB) during maximal isometric bench press in resistance-trained men. Twelve young, resistance-trained men (age: 24.7 4.2 years) participated in a quasi-experimental, within-subject study. Each subject performed three maximal isometric bench press contractions for both shoulder abduction positions, during which PF and sEMG (UPM, LPM, AD, and TB) were measured. Statistical analyses included paired t-tests for PF and two-way ANOVA for sEMG. Results showed no signi cant di erence in PF between 45 and 90 shoulder abduction positions. For sEMG, post hoc analyses revealed signi cant di erences between muscles within each shoulder position: at 45, AD vs. UPM (% = 41.5%), AD vs. LPM (% = 65.4%), and UPM vs. LPM (% = 40.8%); at 90, AD vs. LPM (% = 61.9%) and UPM vs. LPM (% = 41.2%). These ndings suggest that shoulder abduction position (45 vs. 90) does not a ect maximal isometric force production or substantially alter myoelectric activation patterns in resistance-trained men.

KI fragen

Bookmark

View Full Paper