Adductors

The most important of the inside thigh muscles are the three adductors, the longus (long), brevis (short) and magnus (large). All are attached to the lower edge of the pubic bone at their origin and spread out to be fixed along the inner edge of the thigh-bone (femur). Adductor longus lies to the front of the other two and starts with a cord-like tendon attached just to the side of the pubis and spreads out sideways to cover the central third of the femur. Adductor brevis lies just under adductor longus but fixes onto the femur at a higher point. Adductor magnus lies beneath the other two and spreads out almost the entire length of the femur. Being deeper and so large it is very close to the inner hamstring muscles, semimembranosus and semitendinosus in their lower part.

The adductors are less fleshy and less prominent than the other front or back thigh muscles but some parts can still be seen when contracted. The lower attachment of adductor magnus can be felt just above the inside of the knee and the tendon of the upper end in the groin. If you press your legs together while apart, you can feel the tendon contracting and the adductor brevis tendon behind it. The three adductors pull the femur inwards, towards and across your other leg, from the hip. They also turn the femur inwards to turn your toes towards the other foot. They are especially active in a variety of leg movements. Running sideways or side stepping the adductors contract to bring the trailing leg forwards and up to or past the other leg. If running up stairs or a hill the adductors work to pull your thigh inwards as your leg moves forwards. This gives greater economy of movement. Kicking across the body is an action which requires the adductors. A forward and inward motion with the foot turned out will also require sartorius (included as one of the quadriceps muscles). The adductor muscles are used in the sitting stance posture. Gravity attempts to pull the body down and spread the legs in doing so because of the wide nature of this stance. The adductors are strongly implicated to work against these effects. This strengthens and stretches isometrically. It is not a good position for squatting from, however, since the knee joint is out of alignment. You must turn the foot outwards for this to be safe with good form. The narrower the stance then the less the adductors are used and the gluteus maximus muscles (hip extensors or seat muscles) are used more in isolation with the hamstrings and quadriceps. Leaning forward also brings the hip flexors into play on the upper thigh (power squat). If the centre of gravity is moved further back to a more upright position the quadriceps are strengthened rather than the very top of thigh (hip flexors).