Volitional Hamstring Force Production During Closed Kinetic Chain Lower Extremity Exercise in Supine Position: A Randomized Controlled Trial

The hamstring muscle group is a vital constituent to injury prevention and lower extremity rehabilitation. During closed chain activity, hamstring muscle fibers influence dynamic interaction between the pelvis, sacrum, femur and lower leg. The hamstring muscle group functions as a frontal and transverse plane stabilizer, influencing knee flexion deceleration and eccentric extension during forward propulsion [1-3]. The hamstring muscle group is most often injured during high-speed propulsion activities most notably among track runners, football players and hockey players. Consequently, the biceps femoris in particular is considerably vulnerable to strain or injury during moments of acceleration [3-5]. Heiderscheit et al. [6] further noted that the incidence of hamstring re-injury can be attributed to chronic musculotendinous shortening secondary to previous injury [6]. According to Sherry et al. [7], hamstring injuries often require significant recovery time and exhibit a long period of increased susceptibility [7].