Is a joint moment-based cost function associated with preferred cycling cadence?

Eight experienced male cyclists (C), eight well-trained male runners (R), a nd eight less-trained male noncyclists (LT) were tested under multiple cade nce and power output conditions to determine: (1) if the cadence at which l ower extremity net joint moments are minimized (cost function cadence) was associated with preferred pedaling cadence (PC), (2) if the cost function c adence increased with increases in power output, and (3) if the association is generalizable across groups differing in cycling experience and aerobic power. Net joint moments at the hip. knee: and ankle were computed From vi deo records and pedal reaction force data using 2-D inverse dynamics. The s um of the average absolute hip, knee, and ankle joint moments defined a cos t function at each power output and cadence and provided the basis for pred iction of the cadence which minimized net joint moments for each subject at each power output. The cost function cadence was not statistically differe nt from the PC at each power output in all groups. As power output increase d. however, the cost function cadence increased for all three subject group s (86 rpm at 100 W, 93 rpm at 150 W, 98 rpm at 200 W, and 96 rpm at 250 W). PC showed little change (R) or a modest decline (C, LT) with increasing po wer output. Based upon the similarity in the mean data but different trends in the cost function cadence and PC in response to changes in power output as well as the lack of significant correlations between these two variable s, it was concluded that minimizing net joint moments is a factor modestly associated with preferred cadence selection. (C) 2000 Elsevier Science Ltd. All rights reserved.