Muscular activity differences and mechanisms for backhand straight and backhand cross in squash

The purpose of the current study was to identify the differences of the upper extremity muscle activations around three joints of the dominant arm during two patterns of backhand strokes. Ten elite female right-handed squash players participated (age: 18.4 ± 0.8 years; mass: 60.8 ± 1.8 kg; height: 165.2 ± 1.6 cm). EMG data from six muscles around the shoulder, elbow, and wrist joints were recorded. The AD muscle activity of the backhand straight was greater throughout the execution and follow-through phases than the backhand cross (p < .001). In contrast, muscular activity in the PD muscle was greater during the three phases of backhand cross than backhand straight (p < .001). Elbow muscles showed no significant differences except in the follow-through phase, where the TB muscle demonstrated increased activity in the backhand straight. The WF and WE muscles had similar patterns in both strokes. This study provides novel insights into arm muscle activation during two patterns of backhand stroke in squash. Understanding the muscle activity mechanisms of these patterns can inform training strategies, optimize performance, and prevent injury risks to the shoulder, elbow, and wrist during the phases of the two patterns of backhand stroke in squash.