Quadricep Strain, Pull or Tear - Strain of the Rectus Femoris

The truth about the quadricep strain of the rectus femoris muscle.

First, a quadricep strain is a tear of the quadrcep's muscle. This muscle essentially is made up of four (quad) muscles: vastus lateralis, vastus, medialis, vastus intermedius and rectus femoris.

This muscle is unique in the sense that it has three functions. It performs extension (straightening ) of the leg at the knee joint for jumping and running, deceleration (lengthening while under a load) during walking and running and assisting with hip flexion (knee to chest) at the hip joint. It crosses two joints therefore must work twice a hard as the other quadricep muscles.

There are many thoughts for the causes of the quadricep tear or pull:

-overuse

-over training

I believe most quadricep strains are a result of muscle imbalances at the hip poor exercise selection. Here is a well balanced program

There are a few factors that lead to a rectus femoris strain in my opinion. They involve the the major hip flexor muscle - the psoas and the type of exercises given to increase leg strength.

The psoas muscle is deep to the abdominal muscles and has attachments to the anterior aspect of the spine and also to the femur (thigh bone.)

Generally, with many athletes, the psoas muscle tends to be shortened and weak. This leads to the hip rolling forward (anterior pelvic rotation) causing the attachments of the rectus femoris muscle to be closer together. This leads to shortening and tightness of the rectus femoris muscle.

As the foot touches down when the player is running the rectus femoris muscle is lengthening under load to prevent the player from falling on their face. Next the player must push the foot from ground with the contraction (shortening) of both the calf and quad muscles.

The quad muscles must have the strength to both lengthen under load (eccentric contraction) then almost instantly stop (isomertic contraction) then shorten (contract). This is a form of plyometrics (stretch-shortening cycle of muscles).

A shortened and weak hip flexor muscle (psoas) leads to an overworked rectus femoris muscle. This combined with the rectus femoris being shortened may lead to a quadriceps strain pull or tear.

Next putting young soccer athletes in a seated postion to complete leg extensions only reinforces the shortening of both the rectus femoris muscle and the psoas muscle (powerful hip flexor).