The men's steeplechase event requires participants to jump over thirty-five 0.914-meter-tall obstacles, 4 rigid barriers and 1 fixed barrier followed by a 3.66-meter-long water pit per lap, over a 3000-meter distance. This study investigated the effect of increasing running velocity, through a range of 5.33 m/s to 6.66 m/s, on takeoff and landing ground reaction forces, for males during steeplechase hurdling using a force plate embedded under a track surface. Subjects completed 1 trial within each of 6 different pace ranges in a random order, once with a hurdle following the force plate to measure the takeoff ground reaction forces and a second time with the hurdle prior to the force plate to measure the landing ground reaction forces. Within a repeated measures linear mixed model during takeoff, peak vertical force (r2 = 0.1968, p < 0.01) and horizontal propulsive impulse (r2 = 0.0287, p = 0.02) were positively correlated with increasing velocity, and ground time (r2 = 0.1904, p < 0.01) was negatively correlated with increasing velocity. Within a repeated measures linear mixed model during landing, vertical impact force loading rate (r2 = 0.0099, p < 0.01) was positively correlated with increasing velocity and ground time (r2 = 0.2889, p < 0.01), vertical impulse (r2 = 0.1704, p = 0.02), and horizontal braking impulse (r2 = 0.0004, p = 0.05) were negatively correlated with increasing velocity. As male steeplechasers prepared to hurdle at increasing speeds, they produced a greater peak vertical force on the takeoff step while decreasing the ground time during takeoff, and increasing the horizontal propulsive impulse to carry themselves beyond the hurdle. While landing from the hurdle at increasing speeds, the athlete decreased the amount of time spent on the landing stance and the vertical impulse, and increased the magnitude of horizontal braking impulse and vertical loading rate. The relationships of these variables: takeoff peak vertical force, takeoff ground time, takeoff horizontal impulse, landing ground time, and landing vertical loading rate to increasing velocity were all comparable to overground running responses. The data differed from running by not indicating any change in hurdling takeoff horizontal braking impulse; however, the horizontal braking impulse did increase on hurdling landing. It was expected to decrease on hurdling landing due to the foot landing more underneath the center of mass after hurdling compared to running. The decrease in landing vertical impulse as speed increased also differed from normal running steps. We suggest that further research include kinematic measures to better understand the relationship between these variables as hurdling velocity increases.

To identify the dynamic model of the treadmill, this study uses the piezoelectricity material (Po1yviny-lidene fluoride, PVDF) to measure the force under treadmill. With this dynamic model, the ground reaction force (GRF) can be derived from the PVDF sensors. The reliability and precision of the GRF results are verified by replacing the PVDF with the traditional load cell (Force measurement devices). To verify the accuracy of treadmill model, this study acquires three different types of GRF signals (marking time, walking and running) from ten subjects. For the marking time case, the correlation coefficients between the actual and predicated GRF signals are approximately 0.98. This study also demonstrates that the proposed model can provide sufficient bandwidth for the walking and running GRF signals. Finally, via comparing the average GRF profile, inter-personal differences of the GRF signal can be observed. Among the three tested locomotion patterns, the marking time GRF has the highest similarity whereas the running GRF signals has the largest variability.

Treadmill is a highly popular fitness equipments. One of the most important purposes of running is to consume redundant energy of the body. A well designed exercise intensity plan can achieve the benefits of exercise while avoiding sport injuries. Calculating the appropriate exercise intensity is therefore a valuable study issue. Current commercially available treadmills cannot provide sufficient physiological data. In particular, in order to measure the ground reaction force (GRF) of the runners, traditional approach is to design treadmill as a rigid body. Such treadmills are thus expensive and heavy. To estimate heart rate (HR), ECG measurement is typically required. However, sweat can cause the patch to loose and the quality of the signal transmission can also be degraded by environmental noises. Thus the aim of this work is to develop a simple and effective method to assess exercise intensity by estimating HR with GRF.. To achieve this goal, this work places load cells under the legs of the treadmill. By constructing the dynamic model of the treadmill via system identification technique, we can estimate the actual GRF from the measurements of the load cells. After computing the TVI (Total Vertical Impulse) index from the GRF, this work then investigates the linear relationship between TVI and running energy consumption by estimating HR from TVI. Based on the known relationship between HR and exercise intensity, we can observe the runner¡¦s condition from the speed of HR recovery and the HR time response during running. By means of linear regression method, it is found that the linear relations between TVI index and these HR measures are statistically significant. The p-value of such statically tests become even smaller when TVI index is normalized.

Thesis (M.S.)--Indiana University, 2005. / Includes bibliographical references. Also available online (PDF file) by a subscription to the set or by purchasing the individual file.

Thesis (Ph.D.)--Victoria University (Melbourne, Vic.), 2008.

Thesis (M.S.)--Indiana University, 2007. / Includes bibliographical references.

Thesis (M.Phil.) - University of Queensland, 2004. / Includes bibliography.

Thesis (M.A.)--University of North Carolina at Chapel Hill, 2003. / Includes bibliographical references (leaves 166-171).

Thesis (M.S.)--Western Washington University, 2005. / Includes bibliographical references (leaves 114-123). Also available online (PDF file) by a subscription to the set or by purchasing the individual file.

Thesis (M.S.)--Western Washington University, 2005. / Includes bibliographical references (leaves 114-123).