The hamstring is a group of 3 muscles that run down the back of the thigh. The muscles include the semimembranosus, the semitendinosus and the biceps femoris. The semimembranosus muscle forms the bulk of the mass of the muscle group. These muscles bend the knee and also move and extend the leg at the hip joint. As with other frequently injured muscles, the hamstrings span two joints (hip and knee) and therefore are subject to stretching at more than one point.

Hamstring injuries can happen in a variety of ways, with the one common factor being that there is a sudden pain in the muscle, which is directly related to a particular movement or incident.

A gradual pain in the hamstring is usually termed a hamstring pull or strain. This injury happens when the muscles are tight, fatigued, or weakened and are then strained by overwork. Over-training, especially if this involves repetitive movements, is a common cause of hamstring overuse strains. Overuse strains start with only a slight pain, which gradually gets worse as you continue with the activity. The problem with overuse injuries to the hamstring is they tend to recur. Even if they do not develop into an acute tear they can limit your ability to run, jump and stretch your leg out.

A hamstring tear may be the result of an over-stretch injury (i.e. if you have to sprint suddenly when the muscles are cold or tightened because of a previous injury). Over-stretching may happen if your foot slips forward when your leg is straight in front of you, for instance as you land during hurdling. A direct blow to the hamstrings while they are contracting can tear the muscles as well, such as being hit by a ball or racket while running. Inefficient muscle function can also contribute to sudden tears in the hamstrings.

Hamstring injuries are common in sports that require bursts of speed or rapid acceleration such as: soccer, track and field, football, and rugby. Improper warm-up, fatigue, previous injury, strength imbalance, and poor flexibility have been correlated with this injury.

Symptoms
You may feel a sudden pain in the hamstring, which may be as mild as a twinge or as, severe as a searing pain. Bruising may appear immediately or some time after the injury has occurred. It is not uncommon for the bruising and swelling to spread down the leg towards the knee.

Symptoms

• Pain

  Bruising

  Swelling

  Knot or Spasm

  Inability to Straighten Knee

Diagnosis
Strains to the hamstring muscle group are unfortunately prevalent. The diagnosis can usually be made by a complete history and physical exam. The patient will often describe pain in the posterior thigh, particularly during and following activities during which the hamstring is eccentrically activated (lengthening), like running. On physical examination, tenderness and swelling can exist at the location of the injury, which is most often the muscle-tendon junction. Imaging studies including x-rays, are probably not routinely warranted when evaluating hamstring strains. Occasionally MRI scans can be used to help pinpoint the extent and location of the injury.

Treatment
Initial treatment consists of rest, ice, compression, elevation, and pain relief. Compression of the affected area with elastic wrap may help reduce swelling. For pain relief, anti-inflammatory medication can be used for 7-10 days. Once you get the inflammation out let the muscle settle down and start to heal then you must work on getting the range of motion and flexibility back to normal. As you get closer to full range of motion in the hip and knee you may start adding strengthening exercises. Once you begin strengthening exercises it is a good idea to look at the athletes body as a whole checking the ratio of strength from quad muscle (front of thigh) to hamstring (back of thigh) and the ration of one hamstring to another (involved vs. uninvolved).

We use a cybex isokinetic machine to test and graph these ratios as well as functional testing to see if an athlete is ready to go back to activity. Most physicians require the strength be back to within 5 or 10% of the opposite (uninjured) hamstring.
 

Count'R Force Thigh Brace

Offers warmth, compression, and support for prevention and healing. Used for: Thigh bruises Muscle pulls and hamstring strains Torn quadriceps and hamstrings Groin pulls

Prognosis
Returning to activity will depend on the grade of the injury. A grade-one or simple strain of a muscle usually will keep an athlete out for one to two weeks. A grade 2 injury is classified as a major defect where you can actually push on the muscle and see an indentation. It can take anywhere from six to eight weeks to heal a grade 2 tear. A full tear or grade-three injury requires a minimum of 2 months to rehabilitate. This depends of course on the person's previous level of fitness and individual healing rates.

Prevention
Proper strengthening prior to starting any sports activity is important to preventing injury. We recommend a biomechanical evaluation by a physical therapist, who will analyze your gait to see what is happening at the foot, ankle, hip, lower back, and pelvis areas while you walk or run. They will look at old injuries and measure your strength and flexibility to identify any problem areas.

Warm up thoroughly; the hamstring is probably one of the most important muscles to warm-up and stretch before a workout. Stretching after a workout is also important.

Many sports and activities do not strengthen the hamstring muscle group but overemphasize the quadriceps muscles. This can create a muscle imbalance that over time can lead to hamstring injury. It is important to supplement any athletic program with a weight-training regime that includes strengthening the hamstrings. Studies have shown that flexibility and strength training result in improved performance of the hamstring muscle group. So besides helping to prevent injury, stretching and strength training may enhance your performance as well.