Ligaments and Tendons
Tendons and ligaments are fibrous bands of connective tissue that help stabilize body structures and facilitate body movements. The main difference between tendons and ligaments is that they connect different parts of the anatomy. Tendons connect muscles to bones, while ligaments connect bones to other bones.
Ligaments and tendons are made of 2 types of protein fibers: collagen and elastin. Collagen fibers have a small deformation range and high strength. Since collagen has such a high strength, they require more force to break down. Contrarily, elastin fibers have a large deformation range with low strength, meaning they are very weak and can break more easily. Ligaments such as the neck and wrists have more motion and movement because they consist of more elastin and less collagen.
Ligaments and Tendon Injury:
Repetitive motions with inadequate recovery periods are the cause of occupational ligament and tendon injuries due to the constant loading and unloading of force with no rest. Loading is the process of physical stresses acting on the body or on anatomical structures within the body.
A ligament injury occurs during the chronic process of loading and unloading, the tissue becomes longer and more fragile and eventually a small amount of force can easily fracture. In addition, cumulative loading can result in a decrease in bone density which increases the vulnerability of a ligament or tendon getting injured. An example of constant loading is by having improper posture for long periods of time which eventually leads to lower back injury.
Stages of Ligament Healing:
- Acute inflammatory phase – The first stage consists of the formation of blood clot within the damaged region.
- Proliferative phase – New blood vessels are formed while fibroblasts are recruited from circulation to produce new collagen.
- Tissue remodeling phase – The third stage starts after 3 weeks of the injury occurrence. During the wound healing process, there is a progressive maturation of collagen fibers in response to loads experienced by the ligaments. If force is applied in the wrong direction, there can be permanent damage of the ligaments.