|Wednesday, September 1
While many New York Giant fans were concerned how Jason Sehorn's reconstructed knee would respond to the rigors of two-a-day practices this preseason, it is an injury to his hamstring that has kept the star cornerback on the sidelines this summer. Yet Sehorn's plight is not merely endemic to football players-- it's a common affliction in almost every sport.
Why are hamstring injuries so prevalent among athletes? Is there an anatomical basis? Join Dr. Roger McCoy, a member of the Association of Professional Team Physicians (PTP) and team physician for the Arizona Diamondbacks, as he answers these and other questions, including the causes of and treatments for this debilitating condition
What exactly is a hamstring?
Dr. McCoy: The hamstring is a long muscle in the back part of the thigh that has an interesting component in that it crosses over two joints -- it is both a flexor of the knee and an extensor of the hip. As a result, the hamstring has some dual function and is a key component of any walking/running/gait pattern.
What are the common causes of hamstring injuries?Dr. McCoy: There has been a lot of research done in this area and you could almost find a study that could confirm or deny any single claim as far as a cause. A few common causes are being out of shape, not being flexible enough and not being trained for the sport that you're putting yourself through -- i.e., the weekend warrior. Another thing that comes into play is strength of the muscle, not only by itself but in comparison to the opposite hamstring and also in comparison to how strong the person's thigh or quadriceps muscles are. If there is too much strength in one hamstring compared to the other, then certain running patterns or cutting moves are favored by one side, making it easier for the muscle to be strained. If there is too much strength in the front part of the leg, as we seen in basketball players as they push off too quickly, the hamstring can be strained trying to coordinate that action with the quadriceps.
Why is it such a common injury ?
Dr. McCoy: The biomechanics of the muscle itself, the fact that it crosses two joints and the fact that it is a long muscle, are responsible for the great number of injuries to the hamstring. It is probably one of the tightest and least stretched muscles in the body. We also tend to ignore the rest of the body when we look at the hamstring at times, and that can be a common oversight. A person who has had an ankle injury and has hyperpronation at that ankle and has not rehabilitated the ankle properly can place a biomechanical stress not only on the ankle, but on the shin, the knee, the hamstring and lower back. This can play a role in the function of the hamstring, which goes back to the fact that the hamstring crosses over two joints, so it can be influenced by factors both above it and below.
How are hamstring injuries treated?
Dr. McCoy: There is just no one way to rehab a hamstring; that is why these injuries tend to recur. Just when you think an athlete's ready to go back to action, he reinjures it. That said, the first modality of treatment is RICE -- rest, ice, compression and elevation. You get the inflammation out, let the muscle settle down and start to heal and then you work on getting the range of motion and flexibility back to normal. As you get closer to full range of motion, you start adding strengthening exercises and at that point it would be advised to then look at the athletes' body as a whole -- the ratio of strength from quad to hamstring and the ratio of one hamstring to the other. We would look at the ankle, the foot, the hips, the sacrum and the sacroiliac joint, trying to eliminate as many other contributing factors as possible.
We often use a computer machine to subjectively test these ratios, but we can also use functional testing to see if an athlete is ready to go back to activity if such hardware is not available. The functional tests include sprints, figure-8 runs and cutting maneuvers and using the athlete's feedback as to how the muscle feels.
Usually if the strength is back within five or 10 percent of the opposite (uninjured) hamstring, you are where you want to be. However, any good sports physician would caution that just because you have a reading from a machine that doesn't necessarily mean that the injured hamstrings are functional.
Can hamstring injuries be prevented?
Dr. McCoy: Flexibility is probably the key thing along with proper strengthening prior to starting any endeavor. For instance, plyometric training involves a lot of explosive exercises. No one should enter a plyometric training session before he has obtained the flexibility and strength needed for this activity. The same could be said for beginning training camps or practices prior to strengthening and stretching their lower body, back and quads. Unfortunately, people don't come prepared to handle the stresses that are demanded of their bodies.
Another measure of prevention is to evaluate someone's gait prior to activity -- looking at old injuries, examining his biomechanics, not only how flexible he is at the hamstring but seeing what is happening at the foot, ankle, hip and lower back, pelvis and sacroiliac areas.
What is the prognosis?
Dr. McCoy: Prognosis for most muscle pulls, including the hamstring, depends on the grading of the injury. A grade-one or a simple strain of a muscle usually will keep an athlete out for one to two weeks. Once you have major tearing of the muscle, a "defect" where you can actually push on the muscle and see an indentation, that grade-two injury can take anywhere from six to eight weeks to heal. A full tear, a grade-three injury, requires a two-month minimum and that's being realistic. This depends of course, on the athlete and individual healing rates.
Unfortunately, there isn't a set guideline for one to follow to know when an athlete is ready to return; you have to rely on your physical therapists, trainers and the athlete to give you honest feedback as to when he can go back safely. Then use functional tests to help aid you to ensure that you've made the right decision.