Electromyographic analysis of upper limb muscle activation in elite hammer throwers

This study aimed to investigate the electromyographic activation patterns of selected upper limb muscles Pectoralis Major (PM) and Deltoid Medial (DM) on both right and left sides during hammer throwing in elite male athletes. Ten right-handed national-level hammer throwers (age: 23.44±1.4 years) participated in the study. Each athlete performed twelve maximal-effort throws using a standard 7.26 kg competition hammer. Three valid throws were selected for sEMG analysis. EMG signals were recorded using Trigno Avanti wireless sensors (Delsys Inc., USA) and processed using Lab Chart 8.0. Root Mean Square (RMS) values were computed to quantify muscle activation levels. Video recordings were synchronized with EMG data for phase-wise analysis. Paired samples t-tests and Shapiro-Wilk tests were applied to compare right and left side activation. The results revealed significantly higher activation in the right (dominant) side for both Deltoid Medial (DMR: 533±110.9; DML: 386±46.2; p = 0.002) and Pectoralis Major (PMR: 390±65.1; PML: 301±36.0; p< 0.001). These findings confirm right-side muscular dominance in hammer throwing despite the event’s bilateral nature. The study concludes that dominant-side upper limb muscles play a crucial role in shoulder stabilization, force generation, and control during the rotational phases and final release of the throw.