| Abstract: | This study assessed the maximum pushing force that could be exerted by freestanding subjects, using thumbs only, on a small surface located in one of three horizontal positions at nine heights ranging from 13·5 to 169·9 cm above the floor. Each of 102 subjects made nine force exertion trials. Data are given on the cumulative percentages of subjects who could exert various forces at each of the 27 locations. An analysis of variance showed a highly significant effect due to location of the surface and highly significant interactions of location of the surface and trial presentation direction (top-down or bottom-up); of location of the surface and trial presentation pattern; and of location of the surface, trial presentation direction and trial presentation pattern. Maximum forces are exerted at about waist height and are increasingly reduced with increasing distances above and below the optimum location. Right-sided access to pushing surfaces is favoured over left-sided access. |
