by Elliot Place – Ithaca College
Athletes involved in sports that involve sprinting, kicking, or high-speed skilled movements such as football, soccer, rugby, track, and dancing have been shown to be at increased risk for acute hamstring strains. Hamstring strains are the most prevalent hamstring-related injury resulting in loss of time for athletes at all levels of competition due to their significant recovery time and high susceptibility for recurrence. The high recurrence rate is suggestive of inadequate rehabilitation programs and/or premature return to sport and activity. Whether you have just suffered an acute hamstring injury or have experienced one in the past and worry about performing at an optimal level, PT can help you return to sport faster and significantly reduce your risk of re-injury.
Research has shown that the highest risk of re-injury is within the first 2-weeks of return to sport. Working with a PT can help ensure you return at an optimal level and with the knowledge to decrease your chance of sustaining another strain. Your therapist will work with you to address hamstring weakness and fatigue, imbalances in hamstring and quadricep strength and flexibility, and strength and coordination deficits of the pelvic and trunk musculature. Without an adequate rehabilitation program, athletes may experience persistent weakness in the injured muscle, reduced extensibility due to residual scar tissue, and adaptive changes in the biomechanics and motor patterns of sporting movements due to alterations in neuromuscular control.
The act of running at maximal speed has been found to place the hamstring at the highest risk of injury. Studies have shown that hamstrings are active throughout the entire running cycle with maximal activation during the terminal swing phase. During this terminal swing phase, the hamstring is required to contract with maximum force while being stretched to maximum length. It’s job is to control the knee into extension in order for you to take your next stride. In Biomechanics, we call this kind of high-load, high-intensity movement an eccentric muscle contraction. This is when a force applied to the muscle exceeds the force produced by the muscle itself. Typically, our muscles shorten as we contract them such as in a bicep curl. The bicep attaches at the shoulder and inserts at the forearm, and when it contracts it brings the forearm closer to the shoulder.
A bicep curl is a good example of a concentric movement, or the opposite of how the hamstrings act during the terminal swing phase of sprinting. Because the forces required to run at maximum speed are so high, the hamstring muscle becomes lengthened while it is contracting instead of shortening. This results in the muscle acting to help control the knee joint’s motion into extension by pulling in the direction of flexion while the knee itself is moving into the direction of extension in preparation for contact with the ground. Your PT will be highly trained in strengthening the hamstring in these areas and will show you specialized exercises that will help you to protect your hamstrings when they are most at risk.
Bourne, M. N., Timmins, R. G., Opar, D. A., Ruddy, J. D., et al. An evidence-based framework for strengthening exercises to prevent hamstring injury. (2017) Sports Med. 48, 251-267
Erickson, L.N., Sherry, M. A. Rehabilitation and return to sport after hamstring strain injury. (2017) J Sport Health Sci. 6(3): 262-270.
Lindstedt, S. L., LaStayo, P. C., and Reich, T. E. When active muscles lengthen: properties and consequences of eccentric contractions. (2001). News Physiol. Sci. 16, 256–261.
Opar, D. A., Williams, M. D., Sheild, A.J. Hamstring Strain Injuries: factors that lead to injury and re-injury. (2012) Sports Med. 42, 209-226.
Tyler, T. F., Schmitt, B. M., Nicholas, S. J., McHugh, M. P. Rehabilitation after hamstring-strain injury emphasizing eccentric strengthening at long muscle lengths: results of long-term follow up. (2017) J of Sport Rehab. 26, 131-140.