Sprains and Strains - Info & Definitions

Strains and sprains are among the most common causes of lost work time and high workers' compensation claims costs. The impact can be felt for years. No one is immune to sprains and strains, but here are some descriptions, hints and tips developed by the American Academy of Orthopedic Surgeons to help reduce your injury risk:

What is a sprain?
A sprain is a stretch and/or tear of a ligament, the fibrous band of connective tissue that joins the end of one bone with another. Ligaments stabilize and support the body's joints. For example, ligaments in the knee connect the upper leg with the lower leg, enabling people to walk and run.

What is a strain?
A strain is a twist, pull and/or tear of a muscle and/or tendon. Tendons are fibrous cords of tissue that attach muscles to bone.

What is muscle soreness?
Sore muscles result primarily from micro-tears in the muscles from muscle overexertion.

What causes sprains and strains?
A sprain is caused by direct or indirect trauma (a fall, a blow to the body, etc.) that knocks a joint out of position, and over-stretches, and, in severe cases, ruptures the supporting ligaments. Typically, this injury occurs when an individual lands on an outstretched arm; stops or changes direction suddenly; jumps and lands on the side of the foot; or runs/walks on an uneven surface.
Chronic strains are the result of overuse - prolonged, repetitive movement - of muscles and tendons.
Inadequate rest breaks during intensive work loads or training can precipitate a strain.
Acute strains are caused by a direct blow to the body, over-stretching, or excessive muscle contraction.

How does a Damaged Muscle Heal?
The healing process of a muscle strain begins with an inflammatory response, which can last for three to five days. This is a crucial time during which rest and protection of the injured part is vital in order to prevent any further damage. During the inflammatory reaction the body produces chemicals and cells which remove dead muscle fibers and start the repair process.

The Repair Process
The repair process consists of three stages:
• REGENERATION OF MUSCLE FIBRES - New muscle fibers grow from special cells within the muscle.
• FORMATION OF SCAR TISSUE - There is bleeding in the gap between the torn muscle ends, and from this blood a matrix, or scaffold, is formed to anchor the two ends together. This matrix eventually forms a scar within the muscle that makes the muscle more resistant to further stretch damage.
• MATURATION OF THE SCAR TISSUE - The collagen fibers, which make up the scar tissue become aligned along lines of external stress and are able to withstand more force.