Laurence J. Ryan

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Running performance, energy requirements and musculoskeletal stresses are directly related to the action-reaction forces between the limb and the ground. For human runners, the force-time patterns from individual footfalls can vary considerably across speed, foot-strike and footwear conditions. Here, we used four human footfalls with distinctly different(More)
Investigations focused on the gait and physiological limits of human speed have been on-going for more than a century. However, due to measurement limitation a kinetic understanding of the foot-ground collision and how these dynamics differ between individuals to confer speed and limit gait has only recently begun to come forth. Therefore, we designed and(More)
2037 ABSTRACT Running performance, energy requirements and musculoskeletal stresses are directly related to the action–reaction forces between the limb and the ground. For human runners, the force–time patterns from individual footfalls can vary considerably across speed, footstrike and footwear conditions. Here, we used four human footfalls with distinctly(More)
Two experiments evaluated the influence of attentional focus on 10-meter sprint time and start kinetics in a group of collegiate soccer players and highly experienced sprinters. In Experiment 1, the collegiate soccer players were asked to perform 10-meter sprints under an external focus condition, an internal focus condition and a control condition. For the(More)
The relationship between gait mechanics and running ground reaction forces is widely regarded as complex. This viewpoint has evolved primarily via efforts to explain the rising edge of vertical force-time waveforms observed during slow human running. Existing theoretical models do provide good rising-edge fits, but require more than a dozen input variables(More)
Load carriage was used as an experimental tool to evaluate the ability of an anatomically-based, two-mass model of the human body to predict vertical impact and peak forces during running from only four inputs: body weight (W<sub>b</sub>), contact time (t<sub>c</sub>), aerial time, (t<sub>a</sub>), and lower-limb acceleration (a<sub>1</sub>). Simultaneous(More)
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