Impulse for the developmental steps in Biomechanics have frequently been provided by the continuous progress in modern age sciences and technologies, too. During the last few decades a completely new and higher quality has been established in the field of kinemetry by the application of Video technology. The three-dimensional motion analysis from film pictures have been perfected in measuring procedures to a point making it almost a routine method nowadays. Laser technology brought progress for the distance-time measurements as for the transducers of values measured during dynamometric investigations in a decisive scale. At the same time computer technology recently formed and accelerated this progress essentially. Applying computer technologies it was possible to enter into measuring technological problems when movements were to be analysed biomeehanically, which could not be solved in the past because of their huge amounts of evaluational and calculational efforts, as e.g. the projective correction of the motion film analysis, the levelling of falsified measuring signal dynamics, or the simulation of movements of the human locomotor system. Biomechanical modelling could only be started at high gear by applying computer technologies. At this time we find that biomechanical modelling has become an important main line of biomechanical research wor~ everywhere, and tasks to be solved are approached on a wide scale. Connected therewith, biomechanical theories and methodology have also made some progress. This concerns mainly the theoretical constructions to assess the suitability and efficiency of athletic movements, i.e. those criteria that have to be utilized when movements have to be assessed afterwards. One should have such criteria at his disposal particularly whenever computerized optimisations shall be carried out by means of modelling and simulating to justify generalized statements, as compared with the description of certain single cases. Relating the actual boom of software developments in Biomechanics to the progress made in theoretical positions, the latter must be defined as being rather modest ones. These are the reasons why a stronger approach towards theory formation in Biomechanics seems to be urgently necessary. We want to point out her.2 a decisive aspect as far as biomechanical movement analjses are concerned that has -according to our point of view -been taken into consideration only insufficiently or not at all in the past, thereby resulting in incomplete or even wrong assessments of reality. With the exception of athletic movements in endurance sports the energetic input per time unit (mechanical performance) has been considered to a small extent only in Biomechanics. In endurance sports attention was mainly focussed upon the bio-energetic aspect (metabolism and availability of energy), and less upon mechanical performance. Taking the biologically developed muscular strength for granted in Biomechanics and considering it primarily the mechanical cause for human movements the relations between dynamics and kinematics, between force and motor impulses can be enlightened and represented by means of Newton's 2nd axiom only. That point of view would presuppose tha t no other mechanical reason is necessary for the mechanical movement of the human, locomotor system. This means that the lines where Biology and Mechanics meet may be located in muscular force by entering the mechanical effects of muscular tensions produced by biological processes as mechanically independent values Fmu,c into the equations for the interplay of forces. It seems, however, obvious that we must not start from such presuppositions. Sport practice gave evidences for that quite frequently. Theoretical positions of that kind have e.g. led to the wrong attitude that the maximum force contributions which can be developed from a muscular group during strength tests with motorically simple movements and under load conditions basically characterized the levels of strength capacity of that muscular group and should principally be achievable als in motorically more complicated and faster movements. (Putting it into the simple language during training sessions: "Strength is there but cannot be utilized"). Starting from energetic reflections one is forced into another opinion. It holds that muscular strength must not be considered -also from the mechanical point of view -an independent value or primarily the mechanical cause for human movements. Just like any mechanical motor system, there must be energy applied, motor work performed to dislocate masses. That means: the energy input from the accelerative work performed by muscles represents the original cause for the mechanical movement of human locomotor systems. The kinetic energy of moved sub-masses will be increased by accelerative work or decreased by decelerative work.
© Copyright 1987 ISBS - Conference Proceedings Archive (Konstanz). Springer. Published by International Society of Biomechanics in Sports. All rights reserved.