1. Mechanical Advantage
The crutch shaft is the lever arm to which adjustment of the height enables the user to overview the most favorable mechanical advantage according to their anthropometric dimensions.
2. Static and Dynamic Equilibrium
Application: The push-button locking mechanism ensures that the crutch remains stable, and does not shift unexpectedly, keeping the user in equilibrium as they move. 
3. Friction
Application: Additionally, the push button lock mechanism, when deployed, also utilises friction to maintain the length of the crutch at the selected lock length. They reduce chances of slippage of internal components as they rub against each other during functioning.
4. Elasticity and Material Properties
Application: Push-button locking mechanisms are operated by the elasticity of spring in which user is able to make adjustments. When the button is pressed the plunger compresses the spring to thereby free the shaft to move. Pushing the button someone holds down, the button is pushed for it to be locked in that position.
5. Energy Transfer: A Possible Location for Impact Absorption
Application: The choice of the material for the crutch shaft and its construction and the construction of the handle part can reduce the amplitude of the oscillations and thus can make the user’s experience more comfortable. A dynamic system could comprise small shock absorbers or springs, should there be any experiences of impact.
6. Center of Mass and Balance
Application: The height adjustment work enables the crutch to be fit for different users so that they will be able to stand properly and balance during walking.
7. Force Distribution
Application: The handle and underarm area of the crutch should also be designed in such a away to negate pressures points on the body.