What Eccentric and Concentric Movements Are in a Squat?

The squat is an effective leg-strengthening exercise if performed properly. Squats work virtually every muscle within your legs. When broken down into its components, the squat motion is more complex than it may seem. By being aware of both the eccentric and concentric movements in a squat, you can recognize the multiple muscles that are strengthened.

Eccentric Defined

An eccentric motion is one in which a muscle is lengthened during contraction. In terms of a squat, the eccentric movement occurs in the downward phase of the squat motion as you control the movement. During that phase, the muscles in the legs are lengthening to slow the pace of descent. An analogy is lowering a bucket attached to a rope through a pulley. If you let go of the rope, the bucket will simply fall to the ground. But if you slowly release the rope little by little to control the descent of the bucket, you are performing an action similar to that performed by the muscles in the eccentric phase of a squat.

Eccentric Movements in a Squat

In a squat, as you eccentrically lower yourself, your hips are eccentrically flexing. The gluteus maximus and hamstring muscles eccentrically control that motion. Also, your knee is eccentrically flexing, and the quadriceps muscles eccentrically control this movement. And finally, the ankle joint is eccentrically dorsiflexing, as the calf muscles control your descent. Note that these are the movements in a standard squat; different movements may occur in variations of the squat or if your form is not correct.

Concentric Defined

Concentric muscle contractions are visually easier to understand that eccentric contractions. A concentric contraction is one in which the muscle length decreases to perform a movement. In a squat, this would be the lifting phase of the squat as you stand back up. Looking at the rope analogy again, a concentric movement would be similar to pulling a rope attached to a boulder. As you do the work to pull the rope, the boulder gets closer and closer, just as a muscle shortens in a concentric contraction.

Concentric Movements in a Squat

In the squat, as you concentrically stand back up, your hips are concentrically extending. The gluteus maximus and hamstring muscles concentrically contract to shorten the muscles to pull your hips forward. Also, your knee is concentrically extending, and the quadriceps muscles shorten to pull the knee back to a straight position. And finally, the ankle joint is concentrically plantar flexing, as the calf muscles shorten to bring your lower leg back to an upright position. Again, these are the movements in a standard squat; different movements may occur in variations of the squat or if your form is not correct.