The thigh is the muscular powerhouse of the body. Through it runs the toughest and longest bone in the body ­ the femur. The four muscles of the front thigh, the quadriceps, are the strongest thigh muscles. We use them to kick, to run, and to walk. They are often collectively referred to as the quads, short for quadriceps. When they are injured it is rarely in the midsection of the thigh; usually strain occurs at the very top of the thigh, or where they attach to the knee just above the kneecap.

The group of muscles on the inner part of the thigh are called the adductors (A, B, C, and D). They draw the legs together and stabilize your legs while you walk. The adductors are frequently injured near the groin as well as lower in the thigh. There is one small but strong muscle at the outer top thigh, tenser fascia latae, (E) that has a long tendon (F) that runs down to the outer knee. Injury to this muscle has been seen more often, owing to the popularity of long-distance running.

In the back thigh are the hamstrings which help you walk, run, climb, and stand. There are three of them (1, 2, and 3). They run from bottom of the pelvis at the sit bone to the back of the knee, moving outward to both sides and attaching below the knee.

The thigh is attached to the pelvis at a depression, called the acetabulum, forming the hip joint. The hip joint is formed by the top of the thigh bone (the femur) where there is a round shaped protrusion that fits into the side of the pelvis. This ball and socket joint is similar to that in the shoulder except that it is much more stable.

When the hip joint is injured there is a hidden swelling deep within the hip that cannot be seen. This swelling and inflammation may make it difficult to walk, run, sit or cross the legs. Sometimes a tendon of the quadriceps or adductor muscle which cross the front or inner portion of the hip joint respectively, is injured and masquerades as a hip joint problem.

© copyright Ben Benjamin 2001