Anatomy

The thigh is made up of a series of muscles, the powerful quadriceps, those at the front of your thigh and the adductors, running along the inner thigh.

These muscles assist most movements of the legs, namely flexion of the hip, (lifting the leg) and extension of the knee (straightening the leg).

The adductors main function is to bring the leg inwards towards the bodies central line, and also to assist inward rotation of the hip.

There are other muscles, such as 1 TFL (Tensor Fascia Latae), this long muscular tendon, runs from the outside of pelvis, just above your hip joint, down the outside of your thigh. The muscle stops a quarter of the way down your thigh, however a long tendon runs down and attaches just below your knee onto the top of your shin bone (Tibia). Helps stabilize and steady the hip and knee joints by putting tension on the iliotibial band of fascia, (Long Muscle Tendon).

The Sartorius 2 is the longest muscle in the body, and runs from the outer pelvis, just above your hip joint, across your quadriceps and adductor muscles, and attaches along the inner leg, below the knee on your shin bone. The muscle aids flexion and laterally rotates the hip joint and flexion of the knee.

The adductor muscles 3 Pectineus - 4 Adductor Brevis - 5 Adductor Longus - 6 Adductor Magnus - 7 Gracilis, these muscles all originate from the pubis region, and attach onto the inner thigh femur bone. There main function is to pull the leg back towards the bodies central line, however they also help rotate the leg inwards.

There are 4 quadriceps muscles, hence quad. The inner muscle, often very prominent in cyclists is the Vastus Medialis 8. This muscle runs along the inner side of the femur bone, and attaches just below the knee, on the tibia tuberosity (bony ridge on the top of your shin bone).

The Rectus Femoris 9 originates from the outer side of the pelvis, just above your hip joint, and inserts on to the large patella (knee) tendon, through to the tibia tuberosity. Underneath this large powerful muscle, is the forth quadriceps, known as Vastus Intermedialis. This muscle originates at the top of the femur and also attaches via the patella tendon.

The final quadriceps muscle is on the outer side of the thigh 10 Vastus Lateralis and originates on the outer edge of the femur, just below the hip joint, and attaches on the outer edge of the patella tendon.

All of the quadriceps muscle work to extend the knee, i.e. bring the leg from a bent position to a straighten position. Rectus Femoris, because it originates above the hip joint, also works in flexion of the hip, (lifting the leg off the ground).