Principles of Exercise Rehabilitation

Original Editor - Mariam Hashem

Physical Stress Theory

According to Mueller and Maluf, biological tissues adapt to changes in the levels of applied stress. Maintaining tissue tolerance is essential to prevent tissue atrophy, whereas overloading result in hypertrophy. Excessively high level of stresses lead to tissue injury and a potential permanent damage. The magnitude, time, and direction of stress application determine the overall level of exposure to physical stress. Injury may occur due to a high-magnitude stress applied for a brief period, a low-magnitude stress applied for a long duration, and a moderate-magnitude stress applied to the tissue many times.

Mechanotransduction Hypothesis

Refers to the conversion of mechanical loads on the cellular level, eventually resulting in structural changes. Increased bone thickness and width in response to mechanical loading is the classical example of this hypothesis. Regardless of the type of loading, torsional, compressive or tensile, the mechanical stimulus triggers a release of various chemicals, which in turn result in building up layers of tissue and improves load tolerance.

This hypothesis is aligned with a sub-principle of Wolff's law that tissues adapt to the specific applied loads. Exposure to compressive loads, for instance, will qualify the tissue to tolerate the same type of applied loads exclusively.

Physiologically stressing the tissue, below the level of injury, with sufficient time for this adaptive response to occur causes cellular response that strengthen the tissue and improves its tolerance

Mobility and Stability

Maintaining mobility while stabilizing an injured tissue is required in successful rehabilitation. The key here is to avoid rigidity. Muscular rigidity refers to Co-contraction, occurring in response to pain and/or kinesiophbia. Appropriate level of co-contraction which allows mobility to occur once stress is minimized.

The Influence of pain on movement and motor control

Pain has a massive influence on our movement patterns. As a pain avoidance strategy, a person with injured ankle may acquire an antalgic gait. Walking with slight planter flexion and short strides may later develop to a compensatory foot pronation, knee valgus and hip adduction moment, thus affecting tissue stress.

Another example is seen when a person develops a co-contraction of Erector Spinae muscle due to flexion-related LBP. This rigidity results in excessive hip movement to compensate for the loss of lumbar flexion. Additionally, the excessive lumbar extension may cause increased load on facet joint and posterior disc elements.

The fear of movement could possibly develop to catastrophizing and complicate the conditions. Therefore, we need to consider the central elements of pain by implementing desensitization in the rehabilitation program.

Rehabilitation Considerations

Motor skill Learning/Rehabilitation

Teaching the movement involves various levels of learning:

• Acquisition/Cognitive stage: deconstructing the function onto simple movements with repetitions.
• Retention/Associative stage: recalling and delivering the task away from the initial learning time.
• Autonomous/ Flaw stage: the ability to carry out a task without paying attention to tactics. Ideally, we want to deliver our patients to this stage.

Instructing patients in each motor learning stage varies. n the first stage, clause skill is used to eleiminate all external influences and drives the focus internally (Intrinsic focused cues) by asking patient to reflect on the purpose and the mechanism of a simple movement e.g. single leg squat. Repetitions in this stage aids cognition and acquisition. In Retention and Flaw stages, the training should be external or goal focused. For example, asking patient to move towards a certain target, or doing a task while keeping trunk ahead of knees.

Timing feedback is also another important element. constant feedback doesn't allow the patient to reflect and learn. Instead, feedback should be given at the end of the training session or either in extreme good or bad performance.

The rehabilitation then should develop complexity to mimic the reality of patient's occupation or functional aspirations. Acquiring Random Skill training methods, by trianing patient to deliver function on various surfaces, with different external loads and to react to external stimuli.

Re-loading Rehabilitation

Selecting exercise with intention to improve proprioception in the context of what they need to do it needs to be adaptive and progressively challenging over time. an to fit wth certain physical outcomes. understanding strengthning: ability to deliver high force against relatively low repetions.