The Physiology of Injury

Despite of improved education, we still develop injuries. What happens when you injure yourself? Why doesn’t it just get better by itself?

There are 2 very different types of injury: the first being acute, which may be caused by extrinsic factors such as a sudden impact or a direct blow, or intrinsically as a result of a ligament sprain or a muscle tear.

The most common, being a repetitive strain type of injury, or overuse will be discussed here. Any type of repetitive activity can lead to an overuse injury, whether it is lifting heavy boxes all day, or typing on a laptop for hours on end.

The overuse injury results when microtrauma overloads a tissue’s ability to repair itself. This causes acute, then eventually chronic inflammation, resulting in structural changes in the tissue. Symptoms are generally of gradual onset, hardly noticeable initially, but as the activity continues and the tissue weakens, the damaged tissue makes itself known to you.

Inflammation occurs regardless of the cause of injury, it is usually detected by swelling, redness, heat and tenderness if it is superficial. However, deeper structures may not demonstrate these signs.

Treatment for overuse injuries includes relative rest, which means avoidance of the aggravating activities. Modifying movement patterns and behaviour is essential to break the cycle of perpetual tissue overload. It is difficult without a conscience effort on your part. Anti-inflammatory techniques include ice, electrotherapy (ultrasound, TENS, Interferential current), acupuncture, soft tissue treatment, and joint mobilizations. Commencing treatment immediately allows the pain, inflammation, swelling or joint effusion to be controlled early on, preventing them from inhibiting optimal function and allowing you to develop harmful compensation patterns. Manual therapy is used to free up joints and muscles that have become rigid over the years through overuse or neglect. It helps restore full pain free range of motion and is applied to joints of the spine and peripheral joints, affected muscles, tendons, fascia, and nerves.

The most challenging and important factor in rehabilitation of overuse injuries is determining WHY they occurred. It may be something as obvious as a biomechanical fault (poor ergonomics at the computer, or running the same direction on a road with a significant camber, causing excessive pronation). Or it may be a result of muscle imbalance, leg length discrepancy a stiff joint or decreased flexibility.

Muscle atrophy occurs rapidly following injury due to inactivity, pain, inflammation and immobility. Significant strength loss occurs after short periods of immobilization. Muscles also show increased fatigability and therefore less endurance.   Along with the wasting of affected muscles, muscle tightness and alterations in muscle firing can occur, causing poor movement patterns an possibly perpetuating the injury. Physiotherapy will assess and strengthen weak muscles, stretch tight structures, re-educate movement patterns to facilitate correct timing of muscle activity.

Unlike a traumatic injury, an overuse injury may occur very slowly over years, causing a snowball effect within the musculoskeletal system. Our bodies are very effective in adapting and compensating which often causes numerous other troubles. Often I hear people saying “I didn’t even know that was sore/ tight/ weak until you worked on it. Rehabilitation is similar to an onion, we often have to peel away layer after layer to get to the core. The longer an injury has been going on, the more layers of an onion and the longer it takes to restore full function.

The goal of physiotherapy following an injury is to restore your function to its previous level, be that of an office worker or an elite athlete. All musculoskeletal injuries require active rehabilitation. It is also necessary following surgery, fractures or immobilization. The primary aim of rehabilitation is to return you to your previous activity level in the shortest time possible. If rehabilitation is inadequate you may be prone to re-injury of the affected area, or incapable of performing your activities at your pre-injury level, or predisposed to a new injury. The sooner you initiate rehabilitation, the better your outcome.



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