Study of the response of the area of the palm to impact: Relationship between the physical characteristic of the palm impact and the subject perception of the severity of the palm impact

Even though using the hand as a hammer causes injury, the practice continues, and may be increasing, in industry and in jobs that require intensive manual labor. This was an exploratory study aimed at measuring the relationships between the forces of strikes, the relative angles of strikes, and/or the number of strikes (up to 3) with the perception of severity of strikes when using the base of the palm of the hand. Eight subjects struck a metal force plate with the base of the palm of the hand at three levels of force, three levels of angle with respect to the surface of a force plate, and with three different numbers of times in a trial. Subjects were then asked to give a psychophysical rating after each trial. The subjective perception of the severity of each impact and force-time curves were recorded. From each force-time curve, peak force, maximum acceleration of force application, and the area of the force curve from initiation to peak were determined. Sixteen ANOVA models were analyzed.