What Are Eccentric Muscle Contractions?

Learn what an eccentric muscle contraction is, how it works, the different types of eccentric contractions, and how they may affect your daily life.

By HourlyTraining
Edited by Tom Amitay

Published September 30, 2020.

When a heavy load is lifted and a force is applied to a muscle, the muscle will eventually reach a point where the external force is much greater than the force generated by that muscle. When this happens, the muscle will be fully activated but will be forced to lengthen due to the greater external force. This is known as an eccentric muscle contraction.

An eccentric contraction is a type of muscle contraction in which the muscles lengthen while generating force and can be both voluntary and involuntary contractions.

A voluntary eccentric muscle contraction occurs when an object is voluntarily lowered after being raised.

An involuntary eccentric muscle contraction occurs when an object becomes too heavy for the muscle to lift and the object is lowered by gravity, whilst the muscle is still activated and generating force against the object, thereby slowing it down.

Two Main Features of Eccentric Muscle Contractions

Firstly, the absolute tensions achieved are very high relative to the muscle's maximum tetanic tension generating capacity. This means that you would be able to set down a much heavier object than you would be able to lift up.

Secondly, absolute tensions are relatively independent of lengthening velocity. This means that the muscles of the body are very resistant to lengthening.

Examples of Eccentric Muscle Contractions

An example of a voluntary eccentric contraction would be the controlled lowering of a weight during a bicep curl after the weight was raised towards the shoulder by a concentric contraction.

An example of an involuntary eccentric contraction would be when an object is too heavy for a muscle to bear and so it is lowered by gravity, while still under tension, such as the dropping of a heavy deadlift once the weight has reached a point where your muscles can no longer lift it.