Effect of Slide Leg Fatigue Exercise with Tibia Rotation on Selective Activation of Hamstring

This study investigated the effect of tibia rotation on hamstring muscle activation and fatigue during slide leg exercises. Nine healthy male participants (mean age: 22.6 ± 1.2 years, weight: 71.1 ± 6.4 kg, height: 176.5 ± 5.1 cm) performed five sets of slide leg exercises under two conditions, internal rotation (IR) and external rotation (ER) of the tibia. Maximal voluntary isometric contraction (MVIC) and ratings of perceived exertion (RPE) were recorded before as a baseline, and right after each set of exercise. Electromyography (EMG) data were collected from the semitendinosus (ST) and biceps femoris (BF) during MVIC and slide leg exercises. Root mean square (RMS) of EMG data during MVIC were calculated and used to normalized.BR/ Results showed a significant reduction in MVIC for both conditions, with IR decreasing by 28.1% and ER by 21.6% (p 0.01). The ST activation was significantly higher under the IR condition (p 0.01), whereas BF showed no significant difference between conditions. RPE scores increased in both conditions but were higher for IR (p 0.01). These findings suggest that internal tibia rotation during slide leg exercises selectively enhances ST activation while inducing greater fatigue.BR/ The results indicate that IR-based slide leg exercises can be effectively utilized in rehabilitation programs for selective hamstring muscle activation, particularly for targeting the semitendinosus. Further research is recommended to explore the long-term effects and application across diverse populations.