Neville V, Zaher N, Pain M T G, Folland J P
Loughborough University, School of Sport, Exercise & Health Sciences, Sports Technology Institute, Loughborough Park, Loughborough LE11 3TU, United Kingdom.
Int J Sports Med. 2009 Oct;30(10):713-8. doi: 10.1055/s-0029-1231044. Epub 2009 Sep 17.
Standing arm-cranking ('grinding') is predominantly an upper-body exercise, however, the contribution of the legs to this activity is unknown. The purpose of the study was to examine the influence of normal lower-limb movement on physiological strain during arm-cranking. Eight elite professional America's Cup grinders performed two exercise trials, on an adjustable standing arm-crank ergometer with SRM powercrank, in a cross-over design. Each trial comprised of two 5-min stages at the same work rate ( approximately lactate threshold) with the knee joint splinted or normal movement available. Vertical ground reaction forces (VGRF) and knee joint angle were determined from two force plates and sagittal plane video, respectively. Work rate was identical for the two conditions (246 (14) vs. 246 (13) W, p=0.7). Knee joint range of motion and unilateral VGRF amplitude were greater during normal compared with splinted arm-cranking (both p<0.01). There was no difference in VO2 (p=0.2) between the two conditions, however, there was greater VCO2 (8%, p=0.001), RER (11%, p<0.001), V(E) (17%, p<0.001) and HR (7 (3) beats.min(-1), p<0.001) during splinted compared with normal arm-cranking. Furthermore, the rise in BLa was greater after splinted than normal arm-cranking (4.8 (0.8) vs. 3.7 (1.0) mmol.L(-1), p=0.04). These data suggest that the lower-limbs play an integral role in standing arm-cranking, and restricted leg movement markedly affects the cardiovascular and metabolic responses to this activity.
站立式手臂曲柄运动（“摇动”）主要是一种上身运动，然而，腿部对该活动的贡献尚不清楚。本研究的目的是探讨正常下肢运动对手臂曲柄运动期间生理应激的影响。八名美国杯精英职业摇手在一台带有SRM动力曲柄的可调式站立手臂曲柄测力计上，采用交叉设计进行了两项运动试验。每次试验包括在相同工作强度（约乳酸阈值）下的两个5分钟阶段，膝关节要么被固定，要么可以正常活动。垂直地面反作用力（VGRF）和膝关节角度分别由两个测力板和矢状面视频测定。两种情况下的工作强度相同（246（14）瓦对246（13）瓦，p = 0.7）。与固定手臂曲柄运动相比，正常手臂曲柄运动期间膝关节活动范围和单侧VGRF幅度更大（两者p < 0.01）。两种情况下VO2无差异（p = 0.2），然而，与正常手臂曲柄运动相比，固定手臂曲柄运动期间VCO2更高（8%，p = 0.001）、呼吸交换率（RER）更高（11%，p < 0.001）、每分通气量（V(E)）更高（17%，p < 0.001）和心率更高（7（3）次·分钟−1，p < 0.001）。此外，与正常手臂曲柄运动相比，固定手臂曲柄运动后血乳酸（BLa）升高幅度更大（4.8（0.8）对3.7（1.0）毫摩尔·升−1，p = 0.04）。这些数据表明，下肢在站立式手臂曲柄运动中起着不可或缺的作用，腿部运动受限会显著影响对该活动的心血管和代谢反应。
