Ten male recreational runners ranging in age from 20 to 32 years were filmed using 3-D cinematography while running on a treadmill at 3.8 m/s, 4.5 m/ s, and 5.4 m/s. The 3-D segment endpoint data were entered into a computer program that computed the segmental contributions to the upward and forward propulsive impulses on the body (lift and drive, respectively) and to the vertical component of angular momentum (Hz). The results of two subjects who demonstrated asymmetrical arm action are discussed in detail and compared with the mean results computed over all subjects. The results revealed that the arms possess the potential to compensate for each other and for asymmetries elsewhere in the body.
Richard N. Hinrichs is with the Exercise and Sport Research Institute, Dept. of Exercise Science and P.E., Arizona State University, Tempe, AZ 85287-0404.