What is a Pulled Hamstring or Hamstring Strain?

A hamstring strain or a pulled hamstring as it is sometimes called is a tear in one or more of the hamstrings muscles. Strictly speaking there are three hamstring muscles (Semitendinosus, Semimembranosus and Biceps femoris) which are known as the hamstring muscle group. These muscles all originate from the ischial tuberosity of the pelvis (see figure 1). Biceps femoris, in addition, has a second portion, known as the small head, that originates from the lower outer portion of the femur bone itself.

The rear portion of adductor magnus is sometimes also considered as a hamstring muscle due to its alignment. All of these muscles travel across the knee joint - semitendinosus and semimembranosus insert into the medial (inner) aspect of the tibia while the biceps femoris inserts at the head of the fibula bone on the outside of the lower leg.

The hamstrings function predominantly in extending the hip and flexing the knee joints. Understanding how the hamstrings work give vital clues as to their modes of injury. Acute, mild to severe hamstring strains are extremely common in sprinters and hurdle jumpers and in all sports that involve sprinting activities, such as football and rugby.

Strains are graded 1, 2 or 3 depending on severity. Grade 1 consists of minor tears within the muscle. A grade 2 is a partial tear in the muscle and grade 3 is a severe or complete rupture of the muscle.

Grade 1: May have tightness in the posterior thigh. Probably able to walk normally however will be aware of some discomfort Minimal swelling. Lying on front and trying to bend the knee against resistance probably won't produce much pain.

Grade 2: Gait will be affected-limp may be present . May be associated with occasional sudden twinges of pain during activity. May notice swelling. Pressure increases pain. Flexing the knee against resistance causes pain. Might be unable to fully straighten the knee.

Grade 3: Walking severely affected- may need walking aids such as crutches Severe pain- particularly during activity such as knee flexion. Noticeable swelling visible immediately.

Symptoms of a Pulled Hamstring

• A sudden sharp pain at the back of the leg during exercise-most probably during sprinting or high velocity movements
• Hamstring muscles going into spasm-will be associated with pain on stretch and contraction.
• Swelling and bruising.
• If the rupture is severe a gap in the muscle may be felt.

Causes of Hamstring Injuries¹

Some of the more common reasons for hamstring injuries are:

• Doing too much, too soon or pushing beyond your limits.
• Poor flexibility.
• Poor muscle strength.
• Muscle imbalance between the quadriceps and hamstring muscle groups.
• Muscle fatigue that leads to over exertion
• Leg Length Differences. A shorter leg may have tighter hamstrings which are more likely to pull.
• Improper or no warm-up.
• History of hamstring injury.

Prevention of Pulled Hamstrings

The following guidelines are for information purposes only. Seeking professional advice before beginning rehabilitation is recommended.

• One of the most important methods of preventing a pulled hamstring is to warm up correctly- this has been scientifically proven to reduce the risk of hamstring strain. This should consist of some light aerobic exercise.
• A specific strengthening program for the hamstring muscle group is vital in those athletes regularly undertaking sprinting and high velocity sports. It is extremely important to continue to strengthen all other muscles in the region of the thighs, pelvis and lower back to ensure correct muscle balance
• Stretching both before and after exercise

Massage Therapy

Regular deep tissue sports massage performed by our skilled therapists at Advanced Alternatives Massage Therapy can help prevent muscle strains by identifying tight knots and weak points in the muscle. The application of Myofascial Release has proven effective in restoring flexibility to hypertonic tissue.

Sources:

1. http://sportsmedicine.about.com/cs/leg_injuries/a/thigh2.htm