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 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

Sources: [1]