731 Physical Stress Theory

Principle A

change in relative level of physical stress cause a predictable response in all biological tissues

Principle B

biological tissues exhibit 5 characteristic response to physical stress

1. maintenance

2. increased threshold (hypertrophy)

3. decreased threshold (atrophy)

4. injury

5. death

Principle C

physical stress levels that are lower than the maintenance range will result in decreased tolerance of tissues to subsequent stress (atrophy)

Principle D

physical stress levels that are in the maintenance range result in no apparent tissue change

Principle E

Physical stress levels that exceed the maintenance range result in increased tolerance of tissues to subsequent physical stresses

Principle F

Excessively high levels of physical stress result in tissue injury

Principle G

Extreme deviations from the maintenance stress range that exceed the adaptive capacity of a tissue result in tissue death

Principle H

The level of exposure to physical stress is a composite value, defined by the magnitude, time, and direction of stress application

Principle I

individual stresses combine in complex ways to contribute to the overall level of stress exposure; the effect of any given stress will depend on the previous stress experienced of that tissue

Principle J

excessive physical stress that causes injury can occur through 1 or more of the following 3 mechanisms:

1. high magnitude stress, short duration

2. low magnitude stress, long duration

3. moderate magnitude stress, applied many times

Principle K

inflammation occurs immediately following tissue injury and renders the injured tissue less tolerant of stress than it was prior injury

Principle L

several modulating variables contribute to stress thresholds such as

1. Extrinsic factors

2. Physiological factors

3. Psychological factors

4. Movement & Alignment factors