How Are Muscles, Bones & Tendons Related?

Muscles, bones and tendons work together to move the body, as well as protect it.

Protection

• Bones protect fragile organs of the body such as the brain, spinal cord, heart, lungs and some reproductive organs. Some muscles provide additional protection where there are no bones. For example, the external, internal and transverse oblique abdominal muscles protect and support the intestines.

Movement

• Bones are the levers that muscles and tendons act on. If an arm is a lever machine, the bone is the lever, the joint is the fulcrum and the muscle provides the force.

Tendons

• Tendons are fibrous connective tissue that connect muscles to bones. They are avascular--meaning they have no blood vessels--and therefore heal slowly if they are torn, stretched or injured.

Strains

• Strains happen when tendons or muscles get stretched or torn. Some of the most common places for strains are the back or the hamstring tendon.

Achilles Tendon

• One of the most well-known tendons is the Achilles tendon, or calcaneal tendon. It attaches the bone of the heel--the calcaneus--to the calf muscles. It gets its name from Greek mythology. The hero Achilles' mother dipped him into a fountain that was supposed to make him invincible, but she had to hold him by the ankle, so that part was vulnerable. Today, an injury to the Achilles tendon is very painful and debilitating.