ABSTRACT

In the sport sciences, and to some degree in the rehabilitation sciences, the HF/E influence has been primarily in equipment design of such things as golf clubs, tennis rackets, and equipment where product design has focused on maximizing the interface between performer and the actual equipment being used. For example, golf club shafts now have different flex characteristics made from both steel and graphite designed to maximize the different swing characteristics of the performer (e.g., swing speed). Club heads have weight distributions designed to optimize both launch angle of the ball and minimizing the effects of off-center shots that do not precisely impact the so-called sweet spot (the center of percussion). In the domain of rehabilitation equipment HF/E has influenced the design of wheelchairs, walkers, and other equipment assistive devices. The influence of HF/E has less of a presence when discussing variability in sport skill performance per se, or teaching or retraining of rehabilitation skills. Equipment design minimizes variability of the user by engineering into the design the different features of the performer to accommodate the known variability of the operator (i.e., strength and flexibility). This can improve the outcome of a golf shot or tennis stroke by minimizing errors produced by variation in response execution; one might say therefore that such designs assist in producing a more consistent (less variable) outcome, but have little or no influence on the inherent flexibility of the actor’s coordination pattern in producing any specific skilled action, yet can support such performances. It is perhaps interesting to note

that the almost incessant technology improvements in sports equipment (especially in golf and tennis) has produced only modest impact on the average performer but has enhanced the performance of the elite athlete. For example, the handicap index for the recreational golf enthusiast has remained essentially constant (18 hole scores of 88-90 for males), but that for elite performers has dropped due to longer drives, more stable ball flight, higher spin rates, and customized launch angles, to name a few. Advanced equipment design has generated higher profits ($4 billion in 2011), from advances in technology (endorsed by elite athletes!) but mixed results with respect to performance increases across the general population of users.