Convertino V A, Doerr D F, Flores J F, Hoffler G W, Buchanan P
Biomedical Research Laboratory, NASA, Kennedy Space Center, Florida 32899.
J Appl Physiol (1985). 1988 Mar;64(3):1017-21. doi: 10.1152/jappl.1988.64.3.1017.
Leg compliance is "causally related with greater susceptibility" to orthostatic stress. Since peak O2 uptake (peak VO2) and muscle strength may be related to leg compliance, we examined the relationships between leg compliance and factors related to muscle size and physical fitness. Ten healthy men, 25-52 yr, underwent tests for determination of vascular compliance of the calf (Whitney mercury strain gauge), peak VO2 (Bruce treadmill), calf muscle strength (Cybex isokinetic dynamometer), body composition (densitometry), and anthropometric measurements of the calf. Cross-sectional areas (CSA) of muscle, fat, and bone in the calf were determined by computed tomography scans. Leg compliance was not significantly correlated with any variables associated with physical fitness per se (peak VO2, calf strength, age, body weight, or composition). Leg compliance correlated with calf CSA (r = -0.72, P less than 0.02) and calculated calf volume (r = -0.67, P less than 0.03). The most dominant contributing factor to the determination of leg compliance was CSA of calf muscle (r = -0.60, P less than 0.06), whereas fat and bone were poor predictors (r = -0.11 and 0.07, respectively). We suggest that leg compliance is less when there is a large muscle mass providing structural support to limit expansion of the veins. This relationship is independent of aerobic and/or strength fitness level of the individual.
腿部顺应性与对直立位应激的“更高易感性存在因果关系”。由于最大摄氧量峰值（VO₂峰值）和肌肉力量可能与腿部顺应性有关，我们研究了腿部顺应性与肌肉大小及体能相关因素之间的关系。10名年龄在25至52岁之间的健康男性接受了以下测试：测定小腿血管顺应性（惠特尼汞应变仪）、VO₂峰值（布鲁斯跑步机测试）、小腿肌肉力量（赛百斯等速测力计）、身体成分（密度测定法）以及小腿的人体测量。通过计算机断层扫描确定小腿肌肉、脂肪和骨骼的横截面积（CSA）。腿部顺应性与任何本身与体能相关的变量（VO₂峰值、小腿力量、年龄、体重或身体成分）均无显著相关性。腿部顺应性与小腿CSA（r = -0.72，P < 0.02）和计算得出的小腿体积（r = -0.67，P < 0.03）相关。决定腿部顺应性的最主要因素是小腿肌肉的CSA（r = -0.60，P < 0.06），而脂肪和骨骼的预测能力较差（分别为r = -0.11和0.07）。我们认为，当有大量肌肉提供结构支撑以限制静脉扩张时，腿部顺应性较低。这种关系与个体的有氧和/或力量适应水平无关。
