Showing papers on "Stair climbing published in 1987"

Eyeheight-scaled information about affordances: a study of sitting and stair climbing.

Abstract: Previous work has shown that both the perceived and actual critical (maximum) heights of surfaces that afford "sitting on " and "climbing on" can be expressed as constant proportions of each actor's leg length. The current study provides evidence that these judgments of critical action boundaries are based on an existing source of size and distance information that is already scaled with reference to the actor's eyeheight. In Experiment 1 changes in judgments of "perceived eyeheight" (an index of the intrinsic scalar) as a function of viewing distance were shown to be highly correlated with changes in the maximum height that was perceived to afford sitting on or climbing on. In Experiments 2 and 3 observers wore 10-cm blocks and made judgments about whether the heights of various surfaces afforded sitting or climbing. The use of eyeheight-scaled information as the basis for their estimates predicted the obtained pattern of errors in these judgments. With a modicum of experience wearing the blocks, however, observers were able to retune accurately their critical action boundary to a degree that would not have been predicted from their consistent overestimation of the height of the block on which they were standing. These results have implications for understanding how observers obtain information about their specific action boundary.

Effect of range of motion on the success of a total knee arthroplasty

Abstract: Five hundred fifty posterior cruciate condylar total knee replacements rated on the Hospital for Special Surgery knee rating scale were evaluated to determine whether postoperative range of motion had any detrimental effects on the total score. The amount of flexion significantly influenced the total score (P less than .0003), the stair climbing score (P less than .004), and the walking ability score (P less than .02). Pain, the main determinant of success, was not affected by range of motion unless there was a flexion contracture when there was a significant effect (P less than .05).

A biodynamic basis for perceived categories of action: a study of sitting and stair climbing.

Abstract: Actors must determine whether the properties of the surface layout are sufficient to meet their specific requirements for performing an action. Warren's (1984) study of bipedal stair climbing has demonstrated the significance of intrinsic, body-scaled measures of environmental properties for defining perceptual categories relevant to action. Whereas the absolute measure of the perceptual boundary between "climbable" and "not climbable" varied according to the actor's size and mass, the perceived boundary was a constant proportion of each actor's leg length. Our current study examined the perceived maximum seat height (SHmax) for the act of sitting. Experiment 1 delineated the range of surface heights that were perceived to afford sitting on. When expressed as a function of each person's leg length (L), SHmax was remarkably stable across individuals. Unexpectedly, it was quite close to the maximum riser height determined by Warren. Experiment 2 examined whether this similarity reflected a common biodynamic requirement, since climbing and sitting require actors to lift their center of gravity above the surface of support. Perceived critical heights were obtained for both acts using the same methods and apparatus. The perceived maximum heights for each act were virtually identical. These findings are consistent with the possibility that the information used in determining critical action boundaries is already scaled with reference to some physical dimension of the actor.

Multifunctional carriage with multiple wheel suitable for flat ground and stair climbing

Abstract: The utility model discloses a multifunctional carriage with multiple wheels suitable for flat ground and stair climbing. The utility model can be pushed on the flat ground and go up and down on the stair steps having difference heights and widths. The utility model is provided with a traveling mechanism composed of two rows of multiple wheels; the traveling mechanism is arranged on both sides of the carriage frame; the carriage frame is provided with a device for fixing the goods. The carriage can be used as a transportation means; by utilizing a seat board, a sleep board and a bottom board of the carriage which are folded and suspended on the wall board of the carriage, the carriage can be used as a baby carrier, a children's bed and a cradle, realizing one object with multifunction.

Stair-climbing trolley for load carry

Abstract: The utility model discloses a stair-climbing trolley for load carry, which is a tool for transporting the liquid gas storage tank or other weights to climb up and go down the stairs. The present stair-climbing trolley for transporting the liquid gas storage tank is composed of a trolley frame, a shaft and two pentacle wheels. The present stair-climbing trolley is labor saving when transporting the weight to climb up and go down the stairs compared with lifting by shoulder and hands, but is inconvenience for women, the old and the weak. The utility model is characterized in that a set of labor saving spanner is arranged on the shaft of the trolley; the user can climb up the stairs by operating the labor saving spanner to shift the pentacle wheels. The labor saving spanner is mainly composed of a ratchet wheel and a pawl. As the magnification times of the labor saving spanner is about 8 times, the trolley carrying load can be transported up stairs with relatively small force.