The Influence of Effective Mass on the Striking Force of Lead Jab and Rear Cross Punches of Boxers

Background: Modern combat sports, including boxing, categorize participants by body mass to ensure fairness and safety. The effective mass, or the ability to maximize body mass during a punch, significantly impacts striking force. This study aims to explore the relationship between effective mass and striking force in lead jab and rear cross punches of boxers. Material and methods: Thirteen male boxers with an average body mass of 90.6 kg and average height of 184 cm participated. The study employed an AMTI MC12-2K force plate (AMTI, Watertown, MA, USA) and Noraxon Ultium EMG sensors (Noraxon, Scottsdale, AZ, USA) to measure impact force and acceleration. Each boxer performed five maximum-force strikes with both lead jab and rear cross techniques. Results: The rear cross punch generated significantly higher ground reaction force (1709.28 ± 486.62 N) compared to the lead jab (1182.56 ± 250.81 N). However, effective mass values were similar for both punches: lead jab (18.95 ± 5.29 kg, 21.51% of body mass) and rear cross (18.50 ± 5.56 kg, 21.04% of body mass). Higher body mass and longer training tenure positively correlated with higher effective mass. An inverse relationship was found between fist acceleration and effective mass. Conclusions: Effective mass plays a crucial role in punch biomechanics, with similar utilization between lead jab and rear cross punches despite the latter’s higher force. Training focused on optimizing body mass utilization and refining punch techniques can enhance punch effectiveness.