The hamstrings play an integral role in sporting movements such as sprinting and jumping. The hamstrings consist of three muscles; semimembranosis, semitendonosis and biceps femoris. These are biarticular muscles, meaning they have attachment sites crossing two different joints (i.e., the posterior hip and the posterior knee). Crossing two joints give the hamstring two distinct functions. The most commonly understood function of the hamstring is to create flexion of the lower leg. However, when the hips are flexed and the knees extended, the hamstring also contribute to extension of the hip. The latter function is the one most commonly seen in sporting movements. Therefore, one must question why athletes are prescribed several leg flexion exercises such as prone or seated hamstring curls verses those that train the hamstrings as hip extensors which more suitably correspond to sporting motions.
A new study published ahead of print in the JSCR by McAllister et al (2013) investigated the muscle activation patterns of the hamstrings and some surrounding muscles in twelve trained men during four different exercises. The exercises included; prone leg curl, glute-ham raise (GHR), Romanian deadlift (RDL) and the goodmorning. Muscle activity of the biceps femoris (lateral hamstring) was highest during the RDL and GHR exercises. The concentric action of semimembranosis and semtitendonosis was maximized during the GHR while eccentric contraction of these muscles was highest during performance of the RDL. It’s worth mentioning that gluteus medius activation was also assessed and showed the greatest activation during the RDL.
The results of this study have important implications for exercise prescription for athletes. For the purposes of strengthening the hamstrings more specifically to sporting movements involving hip extension (i.e., sprinting and jumping), the GHR and the RDL appear to be effective choices. Since the GHR exercise requires specialized equipment, a suitable substitute would be to perform partner GHR’s where a partner holds the athlete’s feet firmly on the ground while the exercise is performed (depicted below). Try including exercises like the RDL and GHR into your athletes training in favor of leg curling movements to optimally train and develop the hamstrings for sports.
McAllister, M. J., Hammond, K. G., Schilling, B. K., Ferreria, L. C., Reed, J. P., & Weiss, L. W. (2013). Muscle activation during various hamstring exercises. Journal of Strength and Conditioning Research, Ahead of print.