Most of the joints in your body are freely moving joints called synovial joints. These allow you to bend, and jump, and stretch. Muscles are attached to bones by cord-like extensions called tendons. The area where the tendon attaches may be weaker than the tendon itself. In adults, where the growthplate fuses the tendon is weaker than the bone.
Ligaments are strong bands of tissue that attach to the bones and form a joint.
Ligaments provide stability to the joint by restricting movement and holding the bones in place. A growth spurt is a period of rapid growth and usually occurs at about 14 years in males and 12 years in females. Bones tend to grow ahead of muscles, which means that muscles and tendons become tight and more easily strained. Muscles should work well in a well balanced, coordinated way. If a muscle is too strong, weak, or tight, it will lead to an imbalance of muscle function and become a possible cause of injury.