The influence of pedaling rate on bilateral asymmetry in cycling.
The influence of pedaling rate on bilateral asymmetry in cycling.
复制标题
骑车时踩踏频率对双侧不对称性的影响。
DOI：
10.1016/s0021-9290(99)00090-1
复制
发表时间：
1999
影响因子：
2.4
通讯作者：
M. Hull
中科院分区：
文献类型：
--
作者：
W. Smak;R. Neptune;M. Hull
本研究的目的是（1）确定骑行中的双侧不对称性是否随踩踏速率系统性地变化，（2）确定通过踢腿确定的优势腿是否比另一条腿对曲柄周期的平均功率贡献更大，以及（3）确定优势腿的不对称性是否随踩踏速率系统性地变化。为了实现这些目标，我们收集了 11 名受试者的数据，这些受试者以 60 至 120 rpm 之间的五种不同的蹬踏速率以及 260 W 的恒定工作速率进行蹬踏。双边踏板测力计测量自行车平面上的两个正交分力。根据这些测量结果，不对称性通过三个因变量进行量化，即平均正功率 (%AP)、平均负功率 (%AN) 和平均曲柄功率 (%AC) 的百分比差异。对两种情况进行了差异——对于在 60rpm 下产生每个功率量的较大总平均值的腿，不考虑优势的衡量标准，以及通过踢腿确定的主导腿。对受试者样本和个体受试者的这些量进行简单线性回归分析。对于受试者样本，只有平均负功率的百分比差异与踩踏速率呈现显着的线性关系；随着踩踏频率的增加，不对称性减少。尽管对于受试者样本来说，踢腿的主导腿比非主导腿贡献了显着更大的平均曲柄功率，但非主导腿比主导腿贡献了显着更大的平均正功率和平均负功率。然而，由于受试者之间不对称性的高度变异性，对于受试者样本而言，这三个量中的任何一个与踩踏速率均不存在明显的显着线性关系。例如，11 名受试者中只有 4 名受试者的踩踏速率与每条腿的总平均功率百分比差异之间存在显着的线性关系，并且这些关系的性质不同（例如正斜率与负斜率）。结论是，踩踏不对称性在受试者之间差异很大，并且各个受试者可能会表现出不同的不对称性系统变化，踩踏速率取决于感兴趣的数量。
The objectives of this study were to (1) determine whether bilateral asymmetry in cycling changed systematically with pedaling rate, (2) determine whether the dominant leg as identified by kicking contributed more to average power over a crank cycle than the other leg, and (3) determine whether the dominant leg asymmetry changed systematically with pedaling rate. To achieve these objectives, data were collected from 11 subjects who pedaled at five different pedaling rates ranging from 60 to 120rpm at a constant workrate of 260W. Bilateral pedal dynamometers measured two orthogonal force components in the plane of the bicycle. From these measurements, asymmetry was quantified by three dependent variables, the percent differences in average positive power (%AP), average negative power (%AN), and average crank power (%AC). Differences were taken for two cases — with respect to the leg generating the greater total average for each power quantity at 60rpm disregarding the measure of dominance, and with respect to the dominant leg as determined by kicking. Simple linear regression analyses were performed on these quantities both for the subject sample and for individual subjects. For the subject sample, only the percent difference in average negative power exhibited a significant linear relationship with pedaling rate; as pedaling rate increased, the asymmetry decreased. Although the kicking dominant leg contributed significantly greater average crank power than the non-dominant leg for the subject sample, the non-dominant leg contributed significantly greater average positive power and average negative power than the dominant leg. However, no significant linear relationships for any of these three quantities with pedaling rate were evident for the subject sample because of high variability in asymmetry among the subjects. For example, significant linear relationships existed between pedaling rates and percent difference in total average power per leg for only four of the 11 subjects and the nature of these relationships was different (e.g. positive versus negative slopes). It was concluded that pedaling asymmetry is highly variable among subjects and that individual subjects may exhibit different systematic changes in asymmetry with pedaling rate depending on the quantity of interest.