Question

When you bend over to pick up an object, which part of this action involves:

a) Concentric Contractions

b) Eccentric Contractions

Answer 1

Ans:

To pick up an object, the types of muscle contraction can occur due to either shortening or lengthening of muscles in the form of concentric or eccentric contractions. A concentric contraction is a type of muscle contraction in which the muscles shorten while generating force. This is typical of muscles that contract due to the sliding filament mechanism. An eccentric contraction results in the elongation or lengthening of a muscle. Such contractions decelerate the muscle joints and can alter the position of the load force. These contractions can be both voluntary or involuntary.

In order to bend over to pick an object by squatting down, muscles are lengthening in response to a greater opposing force leading to an eccentric contraction while on the way up, the muscles are shortening to generate a force leading to a concentric contraction.