The biomechanical principles

Introduction

In general, the term biomechanical principles refers to the exploitation of the mechanical laws for sports performance optimization. It should be noted that the biomechanical principles are not intended to develop technology, but only to improve technology. HOCHMUTH developed six biomechanical principles for the exploitation of mechanical laws for sports stress.

Hochmuth developed five biomechanical principles:

  • The principle of initial force means that a body movement that is to be carried out at maximum speed must be initiated by a movement that runs in exactly the opposite direction. The correct ratio of initiation movement and target movement must be individually and optimally designed. – The principle of the optimal acceleration path assumes that the acceleration path must be optimally long for the target of a high final speed.

In the case of straight-line movements, this is referred to as translation, and in the case of evenly curved movements, it is referred to as rotation. – In order to follow the principle of temporal coordination of individual impulses, individual movements must be optimally interlocked and perfectly timed. Depending on the movement goal, a temporal optimization of the individual movements can be more important than a phased start of the individual movements.

  • This can just as well be the case the other way round. The principle of counteraction refers to the third Newtonian axiom (Actio equals Reactio) and states that for every movement a counter movement is created. The equilibrium of a human being, for example, is an interaction of movements and counter-movements.
  • The principle of impulse transfer assumes that it is possible to take along impulses by shifting the body’s centre of gravity into another movement with the help of the conservation of angular momentum principle. The biomechanical principle of the initial force plays an important role especially in throwing and jumping movements, where a maximum final speed of the body or of a piece of sports equipment is to be achieved. This principle states that an initial movement in the opposite direction to the main direction of movement produces a performance advantage. The term “principle of maximum initial force”, which is frequently used in the older literature, is no longer used in more recent sports science, as this initial force is not a maximum but an optimum force impact. This topic might also be of interest to you: Theory of Motion

How is this initial force created?

If the main movement is preceded by a movement opposite to the actual direction, this movement must be slowed down. This deceleration results in a force impact (braking force impact). This can be used to accelerate the body or the sports equipment if the main movement immediately follows this “backswing” movement.

An athlete throws a medicine ball upwards with outstretched arms. Initially, the athlete is standing still on the measuring platform. The scale shows the body weight [G] (The weight of the medicine ball is neglected.

At time [A] the test person kneels down. The measuring platform shows a lower value. The area [X] shows the negative force impact, which corresponds to the braking force impact [y].

The acceleration force surge occurs immediately after this braking force surge. The force [F] acts on the mediball. A larger measured value can be seen on the measuring platform. For optimum force development, the ratio of braking force surge to acceleration force surge should be approximately one to three.