What’s the Difference Between the Medial and Lateral Hamstrings?

Anatomy

The hamstring is composed of 3 muscles [1]. The medial hamstrings are the semitendinosus and semimembranosus, while the lateral hamstrings are the biceps femoris short and long heads [1].

The medial hamstrings are most active during movements of knee flexion, as well as hip extension with the knees flexed at 90° [2]. Conversely the lateral hamstrings are most active during movements of hip extension with the knees fully extended [2].

Injuries

Lateral hamstring tears are one of the most common injuries experienced by athletes [3,4]. In addition, the recovery time of a lateral hamstring tear isn’t necessarily better or worse than medial tears [3,4]. Instead, the specific location (fascial, muscle-tendon junction, or central tendon) and size of the tear in the muscle is thought to be a better indicator of injury severity [4,5]. Hamstring strengthening is thought to be an important component of athlete injury prevention across a wide range of sports.

Strengthening

Make sure to bias both the medial and lateral muscles when strengthening your hamstrings to ensure both are being addressed equally. In addition, a recent study showed that athletes that performed endurance-based hamstring exercise program performed better at a hamstring strength test compared to athletes that performed a Nordic hamstring curl program [6]. These findings show the importance of not only developing concentric (muscle shortening) and eccentric (muscle lengthening) strength, but also isometric (muscle endurance) strength when targeting the hamstrings.

Exercises

Here are some medial and lateral hamstring exercises that you can perform at home to make sure that you’re targeting both the medial and lateral muscles.

Medial Hamstring Bias Exercises

Unilateral glute bridges, unilateral glute bridge holds, unilateral glute bridge slide-outs, Nordic hamstring curls

Lateral Hamstring Bias Exercises

Unilateral Romanian deadlifts, unilateral straight knee bridges, unilateral straight knee bridge holds

If you have any questions regarding hamstring injuries, please give us a call at (02) 8411 2050. At Thornleigh Performance Physiotherapy, we can give you an accurate diagnosis and treatment, and to help you get back in action as soon as possible. We are conveniently located near Beecroft, Cherrybrook, Hornsby, Normanhurst, Pennant Hills, Waitara, Wahroonga, Westleigh, West Pennant Hills, and West Pymble. Click on the link below to book an appointment with one of physiotherapists.

References

1. Made, A., Wieldraaijer, D., Kerkhoffs, T., Kleipool, G., Engebretsen, M., Dijk, R., & Golanó, P. (2015). The hamstring muscle complex. Knee Surgery, Sports Traumatology, Arthroscopy, 23(7), 2115-2122.

2. Bourne, M., Williams, M., Opar, D., Al Najjar, A., Kerr, G., & Shield, A. (2017). Impact of exercise selection on hamstring muscle activation. British Journal of Sports Medicine, 51(13), 1021-1028.

3. Moen, Reurink, Weir, Tol, Maas, & Goudswaard. (2014). Predicting return to play after hamstring injuries. British Journal of Sports Medicine, 48(18), 1358-13563.

4. Balius, R., Bossy, M., Pedret, C., Capdevila, L., Alomar, X., Heiderscheit, B., & Rodas, G. (2017). Semimembranosus Muscle Injuries In Sport. A Practical MRI use for Prognosis. 01(03), E94-E100.

5. Pollock, Noel, James, Steven L J, Lee, Justin C, & Chakraverty, Robin. (2014). British athletics muscle injury classification: A new grading system. British Journal of Sports Medicine, 48(18), 1347-13451.

6. Macdonald, B., OʼNeill, J., Pollock, N., & Van Hooren, B. (2019). Single-Leg Roman Chair Hold Is More Effective Than the Nordic Hamstring Curl in Improving Hamstring Strength-Endurance in Gaelic Footballers With Previous Hamstring Injury. Journal of Strength and Conditioning Research, 33(12), 3302-3308.