Pruyn Elizabeth C, Watsford Mark L, Murphy Aron J
Faculty of Health, University of Technology Sydney, Lindfield, NSW 2070, Australia.
School of Science and Technology, University of New England, Armidale, NSW 2351, Australia.
J Sport Health Sci. 2016 Dec;5(4):476-483. doi: 10.1016/j.jshs.2015.12.001. Epub 2015 Dec 8.
Stiffness is commonly assessed in relation to injury and athletic performance. The purpose of this research was to compare the validity and reliability of 3 methods of stiffness assessment using 1 cohort of participants.
To determine inter-day reliability, 15 female netballers were assessed for stiffness twice within 1 week using unilateral hopping (vertical stiffness), free oscillations of the calf, and myometry of various muscles of the triceps surae. To establish convergent construct validity, stiffness was compared to static and dynamic strength measurements.
Test-retest stiffness results revealed that vertical stiffness produced moderate to high reliability results and myometry presented moderate to very high reliability. In contrast, the free oscillation technique displayed low to moderate reliability. Vertical stiffness demonstrated a significant correlation with rate of force development during a squat jump, whilst myometer stiffness measurements from 3 sites in the lower limb revealed significant correlations with isometric rate of force development. Further, significant negative correlations were evident between the eccentric utilisation ratio and various myometer stiffness results. No relationships were established between the free oscillation technique and any of the performance measurements.
These results suggest that vertical stiffness and myometry are valid and reliable methods for assessing stiffness.
僵硬程度通常与损伤和运动表现相关联进行评估。本研究的目的是使用同一组参与者比较三种僵硬程度评估方法的有效性和可靠性。
为了确定日间可靠性，对15名女子无挡板篮球运动员在1周内使用单腿跳跃（垂直僵硬程度）、小腿自由摆动以及对小腿三头肌各肌肉进行肌动测量法，两次评估其僵硬程度。为了建立聚合效度，将僵硬程度与静态和动态力量测量结果进行比较。
重测僵硬程度结果显示，垂直僵硬程度产生了中等到高的可靠性结果，肌动测量法呈现出中等到非常高的可靠性。相比之下，自由摆动技术显示出低到中等的可靠性。垂直僵硬程度与深蹲跳过程中的力量发展速率显著相关，同时下肢三个部位的肌动测量僵硬程度结果与等长力量发展速率显著相关。此外，离心利用率与各种肌动测量僵硬程度结果之间存在明显的显著负相关。自由摆动技术与任何性能测量结果之间均未建立关系。
这些结果表明，垂直僵硬程度和肌动测量法是评估僵硬程度的有效且可靠的方法。
