A. A contraction that occurs in a muscle unexpectedly, eg - a muscle twitch B. A contraction that occurs while a muscle is lengthening C. A contraction that occurs while a muscle is shortening D. A very fast muscle contraction such as during power training E. A slow muscle contraction such as during endurance training
A contraction that occurs while a muscle is lengthening
An eccentric contraction occurs when a muscle is activated while it is lengthening, such as during the return phase of a bicep curl - the bicep is lengthening as the elbow is straightened and is also activated to control the speed of the the arm movement - it is therefore lengthening while contracting.