Purpose: The purpose of this study was to evaluate muscle activation of the upper extremity during the tennis two-handed backstrokes. Methods: Eight skilled female tennis players were asked to perform in this study. Muscle activity was determined using surface electromyographic (EMG) techniques, and the critical instants of backstrokes were determined using high-speed video camera. The EMG activity was recorded from eight upper limb muscles (biceps brachii, triceps brachii, flexor carpi and extensor carpi muscles of both right and left arms). EMG rms values of the burst of different phases were individually calculated. Results: The muscle activation during acceleration phase was larger than other phase. Overall, the least muscle activation observed in the arm muscles during back swing phase. During back swing phase, the flexor carpi of the dominant arm and extensor carpi of the non-dominant arm had high muscle activity. The activity of both arm biceps brachii was significantly lower than the other muscles. The activities of the triceps brachii of the dominant arm and flexor carpi of the non-dominant arm were greatest during the acceleration phase. The activity of flexor carpi of the non-dominant arm was significantly greater than flexor carpi of the dominant arm. The activity of both flexor carpi was greater than the other muscles during follow-through phase. Conclusions: Based on the findings of this study, the muscle activation during back swing phase was smaller than other phase; acceleration phase was larger than other phase. The activities of the triceps brachii of the dominant arm and flexor carpi of the non-dominant arm were greatest during the acceleration phase. Tennis players should strengthen these muscles in order to prevent injury.
Purpose: The purpose of this study was to evaluate muscle activation of the upper extremity during the tennis two-handed backstrokes. Methods: Eight skilled female tennis players were asked to perform in this study. Muscle activity was determined using surface electromyographic (EMG) techniques, and the critical instants of backstrokes were determined using high-speed video camera. The EMG activity was recorded from eight upper limb muscles (biceps brachii, triceps brachii, flexor carpi and extensor carpi muscles of both right and left arms). EMG rms values of the burst of different phases were individually calculated. Results: The muscle activation during acceleration phase was larger than other phase. Overall, the least muscle activation observed in the arm muscles during back swing phase. During back swing phase, the flexor carpi of the dominant arm and extensor carpi of the non-dominant arm had high muscle activity. The activity of both arm biceps brachii was significantly lower than the other muscles. The activities of the triceps brachii of the dominant arm and flexor carpi of the non-dominant arm were greatest during the acceleration phase. The activity of flexor carpi of the non-dominant arm was significantly greater than flexor carpi of the dominant arm. The activity of both flexor carpi was greater than the other muscles during follow-through phase. Conclusions: Based on the findings of this study, the muscle activation during back swing phase was smaller than other phase; acceleration phase was larger than other phase. The activities of the triceps brachii of the dominant arm and flexor carpi of the non-dominant arm were greatest during the acceleration phase. Tennis players should strengthen these muscles in order to prevent injury.