Rectus Femoris is one of the four quadriceps muscles, found on the front of the thigh, in the centre.
It is the only quadriceps muscle that originates above the hip joint, meaning it produces movement at both the hip and the knee, although its main action is at the knee.
It is a spindle shaped bipennate muscle (i.e. shaped like a feather), meaning it has two rows of muscle fibres that run in opposite diagonal directions from a central tendon, which gives it extra power.
Rectus femoris originates from two places at the pelvis having two heads:
The muscle runs straight down the front of the thigh (rectus is Latin for straight) and about two third of the way down, narrows into a thick tendon which attaches to the upper border of the patella.
Some of the fibres of rectus femoris pass around the kneecap joining with the other quadriceps to form the ligamentum patellae which attaches to the tibia (shin bones) on a bony lump known as the tibial tuberosity, just below the kneecap.
Rectus femoris can both extend the knee and flex the hip, as it crosses both joints. It works particularly strongly with combined movement of hip flexion and knee extension such as standing up from a seated position, climbing stairs or coming up from a squatting position. It also works hard during a straight leg raise, the lifting up of a straight leg.
When walking, it is particularly active during the swing phase, as the lower leg comes forwards and the knee extends. When standing upright on both legs, there is essentially no action in the quadriceps muscles, but when standing on one leg or on a moving surface, the quadriceps muscles, will work to actively control the leg.
The most common knee problems associate with rectus femoris are:
If you are suffering from knee problems related to rectus femoris, have a look at:
Muscle Group: Rectus Femoris forms part of the Quadriceps
Location: Front of the thigh, central
Action: Extends the knee and flexes the hip
Origin: Anterior Inferior Iliac Spine (AIIS) and acetabulum
Insertion: Upper border of patella and patella tendon
Nerve Supply: Muscular branch femoral nerve (L2, L3, L4)
Functional Activities: Getting up from a chair, swing phase of walking
Page Last Updated: 11/23/21
Next Review Due: 11/23/23