Matching Items (2)
Filtering by

Clear all filters

137750-Thumbnail Image.png

Preferred Versus Recommended Saddle Height For Optimal Cycling Economy

Description
The purpose of this study was to analyze the effects of changing a saddle height to a scientifically recommended position on cycling economy for competitive cyclists. Participants completed one maximal effort graded exercise test and two sub-maximal 70% economy trials, one at the cyclist’s original saddle height and the second…

The purpose of this study was to analyze the effects of changing a saddle height to a scientifically recommended position on cycling economy for competitive cyclists. Participants completed one maximal effort graded exercise test and two sub-maximal 70% economy trials, one at the cyclist’s original saddle height and the second at the saddle height corresponding with a knee flexion angle of 25° at full pedal extension. Due to experimental error and equipment failure heart rate became the main performance measure and cycling economy tests were conducted at an average of 84.4% of heart rate max. The results revealed no apparent differences in performance between the recommended and original saddle height. However, 2D analysis of dynamic knee angles revealed that at the 25° knee angle condition, knee angle increased by an average of 16.1% from the static position (average dynamic knee angle = 29.02±4.61°). Dynamic measures (32.59±4.88°) taken during the original angle tests were only slightly augmented compared to the static measure (31.5±2.18°). It is possible based on this trend that a difference in performance values was not present because the change between the original angle and the experimental angle was not substantial. Additionally these findings suggest that cyclists adjust to these acute changes in saddle height by altering other kinematic variables in an attempt to find a comfortable position and perform maximally.
ContributorsRiley, Daniel Jacob (Author) / Harper, Erin (Thesis director) / Cataldo, Donna (Committee member) / Aragon, Alexandra (Committee member) / Barrett, The Honors College (Contributor) / School of Nutrition and Health Promotion (Contributor) / Department of Psychology (Contributor)
Created2013-05
137606-Thumbnail Image.png

Asymmetries of Ground Reaction Forces among Dancers and Non-Dancers

Description
The purpose of this study was to determine if there were asymmetries in ground reaction forces (GRF) between dancers and non-dancers, and to see the effect of GRF on external (ER) and internal rotator (IR) strength. Subjects performed double- and single-legged jumps on a force plate with a motion capture…

The purpose of this study was to determine if there were asymmetries in ground reaction forces (GRF) between dancers and non-dancers, and to see the effect of GRF on external (ER) and internal rotator (IR) strength. Subjects performed double- and single-legged jumps on a force plate with a motion capture marker system attached at anatomical landmarks, and then had strength and range of motion (ROM) of their internal and external rotators tested along at degrees of hip flexion. There were no significant differences in GRF between legs for all subjects involved. However, stronger hip ER was negatively correlated with vertical GRF (z-axis), positively correlated with anteroposterior (y-axis) GRF, and higher mediolateral (x-axis) GRF from double-leg trials was positively correlated with knee abduction. Thus, future studies should further investigate GRF broken into axial components as well as the time to peak GRF to determine any relation of these factors to knee valgus and ACL injury risk.
ContributorsDiamond, Alexander (Author) / Harper, Erin (Thesis director) / Ringenbach, Shannon (Committee member) / Wiley, Alex (Committee member) / Barrett, The Honors College (Contributor) / School of Nutrition and Health Promotion (Contributor)
Created2013-05