Hamstring muscle and tendon injuries are common in high-speed running. This post discusses points made in a recent article published in the Journal of Sports Sciences.
Recall in a previous post that recovery parallels the return to sport process. As an individual recovers from an injury, they should be encouraged to progress through exercises that increase in difficulty and sport-specificity. This can be thought of as the right exercise for the right person at the right time. The exercise that is right for an athlete will depend on several factors including the nature of their injury, period of their recovery, and the sport or activity to which they wish to return. The activity this post focuses on is high-speed running.
Mechanism of Injury
The hamstrings are commonly injured during late swing phase of the running stride. This might be visualized as the point of maximal knee drive. Near late swing phase, the hamstrings perform a large isometric contraction to resist extension at the knee and assist extension at the hip. If the muscle fibres are unable to produce the high forces required, or if the pelvis is inadequately controlled, injury may result.
“Remember, over striding. Death for the sprinter” ~ Chariots of Fire
Eccentric are often the go-to exercises recommended for myotendinous injuries. But consider the following:
- Is the benefit of eccentric exercise due to the nature of the contraction or to the fact that the muscle is under load?
- Is the muscle actually contracting in an eccentric way during these exercises or is the lengthening a result of slack in the passive elements of the muscle-tendon unit while the muscle remains isometrically contracted?
- Is an eccentric contraction specific to the type of contraction seen in high-speed running?
Alternative/Additional Exercise Considerations
Van Hooren & Bosch (2016) suggest that high-load isometric contractions are more appropriate to condition the hamstrings in the running athlete. This follows the idea that training eccentrically improves eccentric exercise and training isometrically improves isometric exercise. Therefore to encourage running-specific adaptations that mimic late swing of the running stride, isometric exercises should be encouraged.
Exercises that prompt pelvic control should also be emphasized. As mentioned in the mechanism of injury paragraph, lack of pelvic control may be a factor in hamstring injuries. Muscles to consider when thinking about pelvic control include the iliopsoas, gluteals, and obliques. For instance, activation of the iliopsoas in the take-off leg may pull the pelvis into an anterior tilt, lengthening the hamstrings on the swing side.
So, some guidelines for conditioning the hamstrings in the running athlete:
- Load the hamstrings! The hamstrings are maximally loaded in late swing. The goal is to replicate this maximal load during exercise.
- The hamstrings resist knee extension and assist hip extension. Multi-articular exercises should be performed with an emphasis on resisting a hip flexion torque.
- Free the pelvis! Give the athlete the opportunity to explore and control their optimal anterior-posterior pelvic orientation.
- Manipulate hip and tibial rotation. Athletes who race on a track experience differences in the forces experienced through the medial compared to lateral hamstrings. The biceps femoris is activated more in the inside leg, and semimembranosus and semitendinosus in the outside leg. Manipulating tibial and hip rotation while loading the hamstring can help reproduce the activation pattern felt by runners who run in circles.
- Engage in multidisciplinary discussion — coach, athlete, trainer, therapist, etc.
- A coach may have better ideas for sport-specific drills that encourage inter-muscular cooperation than a therapist.
Van Hooren, B & Bosch, F. (2016). Is there really an eccentric action of the hamstrings during the swing phase of high-speed running? Part II: Implications for exercise. J Sports Sci., [Epub ahead of print], 1-12