Flexor muscle

A flexor muscle is a skeletal muscle whose contraction bends a joint, decreasing the angle between components of a limb, such as bending the knee or elbow. This action is known as flexion.

The type of muscle that has the opposite effect is the extensor muscle, which opens a joint, increasing the angle between limb components. Some of the flexor muscles of the upper limbs are: the brachialis and the biceps. Other types of muscles include: abductors, adductors,  supinators and  rotators In humans, some muscles include 'flexor' in their name. Some examples are:
 * Flexor carpi radialis
 * Flexor carpi ulnaris
 * Flexor digitorum profundus muscle