A tendon is a tough yet flexible band of fibrous tissue. The tendon is the structure in your body that connects your muscles to the bones . The skeletal muscles in your body are responsible for moving your bones, thus enabling you to walk, jump, lift, and move in many ways. When a muscle contracts it pulls on a bone to cause movements. The structure that transmits the force of the muscle contraction to the bone is called a tendon.
Tendons come in many shapes and sizes.
Some are very small, like the ones that cause movements of your fingers , and some are much larger, such as your achilles tendon in your heel. When functioning normally, these tendons glide easily and smoothly as the muscle contracts. In some cases a tendon will run within a sheath. Inflammation of this sheath can cause an entrapment of the tendon, as is the case in the syndrome trigger finger . Sometimes the tendons become irritated for a variety of reasons, and the action of pulling the muscle becomes difficult.