opinions and comments A Moment for Biomechanics To the Editor:

As an engineer and physiologist who has been active in the teaching and re-search of biomechanics for over two decades, I read with interest your De-cember 1984 special issue on biome-chanics. I was aware of some of the individual contributions to this issue and commend your efforts to upgrade American physical therapists ' under-standing of biomechanics. I would like to write this letter with a view to correcting two of the questions addressed by authors in that special is-sue. The first, a minor semantics ques-tion, deals with the relation of kinesiol-ogy to biomechanics, which I believe was not clarified correctly by several authors. The second and major criticism deals with one paper that presents what I believe is a totally incorrect biome-chanical technique that appears to be accepted by most of your readership. On this latter question, I refer only to existing published papers and to the basic laws of mechanics. What is kinesiology? In the discus-sions regarding kinesiology and biome-chanics, it is important to define kine-siology first. Kinesiology is the science of the study of human movement and, as such, includes all scientific factors, not just forces, affecting that movement. These factors can be psychological (eg, motivation and cognition), physiologi-cal (muscle metabolism and cardiores-piratory response), neural (motor con-trol), and biomechanical (kinematics, kinetics, anthropometry, and tissue me-chanics). Thus, biomechanics is just one subset of kinesiology. This is how kine-siology is defined at the University of Waterloo, which probably has the larg-est kinesiology department in North America (550 undergraduate students