A "flexor" is a type of muscle that helps bend a joint in the body. When a flexor contracts, it pulls on the bones, causing the angle between them to decrease. For example, the biceps muscle in the upper arm is a flexor that helps bend the elbow. Flexors are found in various parts of the body, including the arms, legs, and fingers. They work in opposition to extensor muscles, which straighten joints. Proper functioning of flexors is essential for everyday movements, such as lifting objects or walking.