Kraaijenbrink, C. (Cassandra) (2015) Power transfer in sub-maximal hand cycling: Effects of gear ratio and power output on mechanical efficiency and force application in sub-maximal synchronous hand cycling in able-bodied men. thesis, Human Movement Sciences.
Full text available on request.Abstract
Objective To investigate the effects of power transfer on both the mechanical efficiency and the forces applied to the handle during sub-maximal synchronous hand cycling at 1.94 m/s. It is hypothesized that a small gear ratio combined with a higher power output will lead to a better force application and mechanical efficiency. Method Twelve able-bodied men rode a hand cycle on a motorized treadmill at a velocity of 1.94 m/s. They performed three sessions of 3x4 minutes exercise blocks. Within each session gear ratio (0.632, 0.741 and 0.843) was changed in-between blocks. Across each session external power output (no pulley system, +10W, +20W) was changed. Forces at the handlebar and oxygen uptake were measured to calculate the mechanical efficiency and the fraction of effective force. Also the heart rate and rate of perceived exertion were measured throughout the sessions. To analyze the effects of gear ratio and power output on synchronous hand cycling, a repeated measures ANOVA was performed (p<0.05) Post-hoc pair wise comparisons were done using Bonferroni adjustments. Results An effect of both gear ratio and external power output was found on mechanical efficiency and fraction of effective force. No interaction was found between the settings. The value of ME and FEF showed the highest values in the condition: gear ratio 0.843 and external power output +20W (mean: 36W). Participants use typically a pull strategy during the cycle to transfer power to the handlebar. With an increase in external power, this pull force becomes more apparent. Conclusion According to the results, a high gear ratio and a high power output lead to more efficient hand cycling. This setting will lead to a high crank resistance. If one wants to increase the resistance of the crank in daily use, one has to increase the gear ratio. It is advised to propel with a heavier gear setting in sub-maximal hand cycling. Keywords Hand cycle; Sub-maximal exercise; Power output; Gear ratio; Mechanical Efficiency; Force application
| Item Type: | Thesis (UNSPECIFIED) |
|---|---|
| Supervisor name: | Vegter, dr. R.J.K. and Woude, prof. dr. L.H.V. van der |
| Faculty: | Medical Sciences |
| Date Deposited: | 29 Apr 2022 12:31 |
| Last Modified: | 29 Apr 2022 12:31 |
| URI: | https://umcg.studenttheses.ub.rug.nl/id/eprint/3164 |
Actions (login required)
 |
View Item |