How to prevent and treat hamstring injuries

The hamstrings are a group of muscles that form the back of the  thigh. They run from the pelvis to just below the knee joint. The  three most commonly referred to muscles of the hamgstrings are the Biceps Femoris, the  Semimembranosis and the Semitendinosis. These muscles are very commonly injured for a variety of reasons. They span two joints: the hip and knee. They act as hip extensors and more importantly as knee flexors. It is in the function as knee flexors that these muscles are most frequently injured.

The classic scene that everyone has witnessed is the 100-meter sprinter pulling up lame in the middle of the race grabbing the back of his leg and going down in a heap. What exactly went wrong to cause this  catastrophic muscle failure? To understand and prevent this from happening to you, we need to understand a few basics of the way muscles work.

For muscles to generate force they shorten their fibers. This is called a concentric or positive action. When a muscle lengthens and is contracting this is called an eccentric or negative contraction. Most acute muscle injuries are the result of negative contractions. This is what happens to the sprinter who is pushing and lengthening the stride and feels the dreaded pop. As the lead foot strikes the ground and the leg is extended the runner attempts to pull the leg through, and, if the muscle is weak or overtaxed, a tear may occur.

Not all injuries are the same. Strains are simple injuries where the muscle fibers are simply overstretched. No real damage occurs. There is minimal swelling and mild soreness. The injury can be treated with just mild activity modification. Tears are generally graded as mild, moderate or severe. Mild tears involve very few fibers are are basically treated just like strains.

Moderate tears involve disruption of the muscle fibers. These are usually accompanied by swelling, mild bruising and pain. There may be pain with simple activities like walking.  Treatment involves rest, ice, elevation, and gradual strengthening. The return to sport is 2 to 6 weeks. Physical therapy is often very helpful in returning to sport.

Severe tears result in large if not complete areas of muscle discontinuity. Surgery is indicated only in the rare case of the  injury happening at the attachment place between the tendon and the bone. Most injuries involve the actual muscle fibers. Treatment often consists of crutch walking initially, followed by similar treatment as in moderate tears although the recovery is much longer. With severe tears people have great difficulty in bending their knees due to pain, stiffness, swelling and the inabilty to get the hamstring  to contract.

What can be done to prevent these injuries? One very common theory for the genesis of injury is muscular imbalance. It is theorized that  when the quadriceps are too powerful, they overpower the hamstring, leading to hamstring failure. The hamstring should be about 60 percent as strong as the quadriceps. Tight lower back and tight hamstrings are felt to predispose one to this type of injury. Poor preparation -- such as trying to sprint full blast without adequate warm up or base -- can also result in hamstring injuries. Warm ups should consist of dynamic, not static, stretching. Dynamic stretching consists of stretching while moving. Trying to lengthen the muscles in the positions that they will be used in while participating in their athletic events. This is the only type of stretching that has is beneficial and will not only prevent injury but will enhance performance.