Age-Related Differences in Bilateral Asymmetry in Cycling Performance

Bilateral asymmetry, a form of limb laterality in the context of moving two limbs, emerges in childhood. Children and adults show lateral preference in tasks that involve the upper and lower limbs (Porac & Coren, 1981; Porac, Coren, & Dunca, 1980). The importance of research in limb laterality is the insight it could provide about lateralized functions of the cerebral hemispheres (Pompeiano, 1985; Previc, 1991). Because there has been less research on lower limb preference than handedness (Gabbard, & Iteya, 1996; Gentry & Gabbard, 1995; Peters, 1988), studying lower limb preference can be a useful measure in understanding the underlying neuromuscular functioning (Peters, 1988, 1990). Several researchers on hand laterality suggested that consistent right-handed children are motorically superior to their inconsistent (mixed-sided) and left-handed peers (Gottfried & Bathurst, 1983; Kaufman, Zalma, & Kaufman, 1978; Tan, 1985). A general observation from the literature on footedness hints that it may be a more sensitive index than handedness in motor performance (Bradshaw, 1989; MacNeilage, 1991; Peters, 1990). It has been suggested that footedness is less subject to dextral social pressure and, therefore, a better indicator of hemispheric specialization than handedness (Peters, 1988; Searleman, 1980). However, no evidence shows the mixedor left-footers are at a performance disadvantage compared to right-footers, and the description of foot laterality patterns across the lifespan is quite sparse. Analyzing bilateral asymmetry as a function of pedaling rate is important for a variety of reasons. One concerns the adaptability of the developing motor system to adjust to changing task requirements. Another concerns the potential influence of bilateral asymmetry on success of motor skill performance (Nonis, Larkin, & Parker, 2005; Teixeira, Silva, & Carvalho, 2003). Identifying the less dominant limb may help educators develop training programs to improve children’s motor skill performance. Finally, quantifying pedaling asymmetry across different pedaling rates could provide insight into motor control principles for left/right coordination, which have been investigated in previous studies (Arsenault, Winter, & Marteniuk, 1986, Daly & Cavanagh, 1976; Patterson & Moreno, 1990). An advantage of pedaling over other motor tasks is that identical kinematics across all trials can be created among individuals with different developmental characteristics. Moreover, the task demands of pedaling can be controlled; thus, performance comparisons can be made among age groups. It is important to have each individual perform the same task in order to eliminate confounding performance factors (i.e., different performances because individuals did not move the same way). A number of previous studies examined bilateral pedaling mechanics in adults (Cavanagh, Petak, Shapiro, & Daly, 1974; Patterson & Moreno, 1990; Sanderson, 1991), but only a few addressed bilateral asymmetry across different pedaling rates (Chavet, Lafortune, & Gray, 1997; Daly & Cavanagh, 1976). It was reported that bilateral asymmetry in cycling changed systematically with pedaling rate in adults, and the asymmetry was not related to leg dominance (Daly & Cavanagh, 1976; Fregly & Zajac, 1996). At present, little is known about the function of bilateral asymmetry with changing pedaling rate in children. A gap in our knowledge is the information necessary to understand the effect of pedaling rate on underlying bilateral motor control in children. Therefore, the purpose of this study was to examine whether bilateral Age-Related Differences in Bilateral Asymmetry in Cycling Performance