Perceptual judgments for stair climbing as a function of pitch angle     

Maraj BK 《Research quarterly for exercise and sport》2003,74(3):248-256

Two experiments explored perception and action for stair climbing, with manipulations to the stair dimensions. In Experiment 1, a custom-built apparatus manipulated the stair dimensions, while three groups of participants made perceptual judgments of climbability. The groups differed significantly for absolute leg length (p < .0001), but there was no significant difference between the groups when stair dimensions were calculated relative to leg length. The selected tread depths and riser heights reflected constant proportions of participants' leg length. Using the pitch angles formed as a composite metric, the results revealed that all groups selected 60 degrees as the limit for climbability. Experiment 2 scaled pitch angle systematically from 20 degrees to 80 degrees, and participants judged 65 degrees and beyond to be unclimbable. These results provided evidence that pitch angle might be used in perceptual judgments for stair climbability.  相似文献   

Variance and Invariance in Expert and Novice Triple Junipers     

Brian K. V. Maraj PhD  Digby Elliott  Timothy D. Lee  Barbara J. Pollock 《Research quarterly for exercise and sport》2013,84(4):404-412

Abstract

The purpose of this study was to examine relative timing, relative distance, and effector independence characteristics of the triple jump. We videotaped expert and novice triple jumpers using standing and running starts. On some trials, the triple jumpers were required to take off from their nondominant leg. Gentner's (1987) interaction test was used to assess the proportional duration model in describing the timing of the component submovements. For both experts and novices, the proportional durations varied with the type of start. For experts, the relative timing of the jump components was independent of the take-off leg. The findings were mixed for the novices. Similar results were obtained when relative distance was examined. These results are discussed with respect to constructs related to variability in skilled performance.  相似文献