by Mitch Hauschildt, MA, ATC, CSCS
Hamstring injuries have long been feared by athletes and coaches alike. The sight of an athlete dropping to the ground as if hit by a sniper bullet is disturbing to anyone who witnesses it. Months of speed training and conditioning can be quickly negated with one hard sprint. To make things worse, many athletes have a tendency to develop what has been termed “chronic” hamstring injuries, ending seasons prematurely and in some cases shortening careers.
In order for us to prevent and/or treat hamstring injuries, we must first understand how the hamstrings work during athletic movements. Literature demonstrates that the hamstrings’ primary responsibility is to decelerate the lower leg to control toe placement while sprinting. In order to do this, the hamstrings must contract eccentrically (as they lengthen) to slow the lower leg to a controllable speed and to absorb energy. By nature, the eccentric contraction is very difficult for any muscle, especially at high speeds. This is why most hamstring injuries occur just prior to or right at toe placement at the end of the recovery phase of the running cycle.
The anatomy of the hamstrings are such that they span both the hip and knee joints, making it possible to perform several movements. The hamstrings originate at the ischial tuberosity on the pelvis and insert on the lower leg. As the muscle shortens, it will perform hip extension, knee flexion, or both. With that being said, the hamstrings are not intended to perform hip extension during sprinting. Even though the hamstrings can assist with hip extension, the glutes are much better suited for this movement. If the glutes are weak or not working properly, the hamstrings have to perform the bulk of hip extension and become overtaxed. This is called synergistic dominance and will lead to overuse and eventually pain.
When we look at hamstring injuries, there are several key causes:
- Strength: There are actually 2 strength issues when looking at the hamstrings. First, while very rare, there are instances where an athlete can become so quad strong and dominate, that they overpower the hamstrings. This rarely occurs and usually only occurs with bodybuilders and specific sports that are quad dominant. The second strength issue is much more of a problem for most people. As we discussed above, the hamstrings contract eccentrically during sprinting, yet many of us have been taught over the years that hamstring strengthening is best achieved through concentric means (leg curls). This does very little to improve the function of the hamstrings.
- Flexibility: Conventional wisdom has stated that in order to prevent hamstring injuries, we need to stretch the hamstrings. Looking again at the anatomy of the hamstrings, we can understand if the pelvis becomes rotated forward (anteriorly) the ischial tuberosity will rise and thus put the hamstrings on stretch. Oftentimes, this happens when the hip flexors on the front of the pelvis become tight and shortened, rotating the pelvis anteriorly. When an athlete combines a prestretched position with a very difficult eccentric contraction, it is easy to understand how hip flexor flexibility deficits play a much larger role on the hamstrings than hamstring tightness.
- Trunk Stability: The deep inner muscles of the core (specifically the transverse abdominus, multifidus, pelvic floor, and diaphragm) are responsible for stabilizing the pelvis. If the core is unstable, the pelvis will be allowed to enter the same forward tilt mentioned above and put the athlete at risk for injury.
- Neuromuscular Response: At times, an athlete may run into a situation where their hamstrings “forget” the proper sequence needed for efficient movements. It becomes a timing issue. This is especially true for athletes who perform hill training as a means of power development. When they run uphill, the glutes, quads, and calves turn on at a very high rate to propel the body forward. When this happens, the concept of reciprocal inhibition comes into play. Reciprocal inhibition states that when one muscle contracts, the opposite muscle relaxes. The greater the contraction, the greater the relaxation. This can be good for speed training, because teaching over active hamstrings to shut down can minimize braking forces during sprinting. However, too much of a good thing can cause problems. Teaching the hamstrings to shut down over and over, can disrupt the proper timing needed when sprinting on flat ground.
- Biomechanics: The mechanics of the entire lower extremity also need to be considered. Looking at the mechanics of the pelvis and hips are important for those athletes with recurrent injuries and/or injuries that always occur on one side of the body. If an athlete presents with a rotation or upslip of one side of the pelvis, they will have a functional leg length discrepancy. Many athletes also present with an anatomical leg length discrepancy where they are naturally built with one leg longer than the other. Evaluating a leg length or lumbopelvic dysfunction is part of a very detailed evaluation process, but something that should always be considered.
Now that we understand the risk factors for hamstring injuries, we need to figure out how to appropriately address them.
- Strength: As for volume, make sure there is always equal volume of pushing and pulling. This will ensure that your athletes will not become quad dominate. Second, get your athletes off of the leg curl machines where they strengthen the hamstrings concentrically, and strengthen them eccentrically through Romanian Dead Lifts, Good Mornings or other eccentric hamstring movement. These exercises work the hamstrings as they get longer and replicate the demands of the hamstrings during sprinting.
- Mobility: Spending time mobilizing the hip is very valuable here. This includes stretching the hip flexors, but should also include the hip internal and external rotator and utilizing exercises such as band mobilizations to improve capsular mobility and help the athlete to decrease tone in the area.
- Trunk Stability: Reset the timing to make sure that their deep stabilizers turn on first and off last by utilizing core engaged movements such as marching, leg lowering and dead bugs. Multisegmental rolling is also a great choice and utilizing a diaphragmatic taping technique can help accelerate this process. Farmer’s carries are a great intervention for this as well, as they are basically a moving plank and allow you to work on pelvic position while moving.
- Neuromuscular Response: The simple fix for neuromuscular firing issues is to integrate ground based sprint training along with hill running. Also, basic sprint technique drills that have been traditionally used for track athletes (i.e. A Skips, B Skips, High Knees, Butt Kicks, etc.) can pay valuable dividends for preventing injury. Performing drills 2-3 times per week for 10-15 minutes will keep the muscles of the lower extremity constantly working in the sequence that they were intended to.
- Biomechanics: As stated above, this evaluation process is highly technical and should be left to qualified medical personal. The important thing to take from this is to know your athletes. If they have recurrent injuries that they can’t seem to shake, or if you see that they have a history of right or left sided injuries, they need to be evaluated from the feet to the hips and everywhere in between to find the weak link.
As always, all of this should be incorporated into a comprehensive program including a proper dynamic mobility warm up, power development, stability training, strength training, speed and agility training, and conditioning to work properly. With that in mind, making some simple changes to the already quality program that you are performing will quickly eradicate hamstring injuries from your team. Your players and their fans will thank you.
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