Abstract
Push/pull forces in unrestricted but known postures were measured in three male and three female volunteers with varied anthropometric characteristics. The subjects performed maximal isometric one handed or two handed push or pull, using two stances (feet side by side or one in front of the other), on handles set at three different heights (67, 109, and 152 centimeters). The handles were connected to an electronic load cell and readout device. High traction, nonskid flooring and soft sole shoes were used and permitted the subjects to assume extreme leaning postures without risking a slip. The subjects were permitted to experiment until they achieved what they believed to be their optimal posture. Sagittal plane photographs were then taken, and the angles of major body joints in their optimal postures were recorded along with the isometric force produced. When the side by side stance was used, pushing and pulling strength values were not significantly different. With the feet apart stance, however, men in particular were capable of significantly greater pushing strength than when pulling. Comparison of handle heights showed that strength was diminished in both men and women when the high handle was used. The use of two hands increased both the push and pull strength values significantly. Postural analysis indicated that the postures chosen by the volunteers were reasonably logical by biomechanical criteria.
