Blomkvist Andreas W, Eika Fredrik, de Bruin Eling D, Andersen Stig, Jorgensen Martin
Department of Geriatric and Internal Medicine, Aalborg University Hospital, Copenhagen, Denmark.
Institute of Human Movement Sciences and Sport, Department Health Sciences and Technology, ETH Zurich, HCP H 25.1, Leopold-Ruzicka-Weg 4, CH-8093, Zürich, Switzerland.
BMC Musculoskelet Disord. 2018 Apr 2;19(1):96. doi: 10.1186/s12891-018-2015-9.
Force steadiness is a quantitative measure of the ability to control muscle tonus. It is an independent predictor of functional performance and has shown to correlate well with different degrees of motor impairment following stroke. Despite being clinically relevant, few studies have assessed the validity of measuring force steadiness. The aim of this study was to explore the reproducibility of handgrip force steadiness, and to assess age difference in steadiness.
Intrarater reproducibility (the degree to which a rating gives consistent result on separate occasions) was investigated in a test-retest design with seven days between sessions. Ten young and thirty older adults were recruited and handgrip steadiness was tested at 5%, 10% and 25% of maximum voluntary contraction (MVC) using Nintendo Wii Balance Board (WBB). Coefficients of variation were calculated from the mean force produced (CVM) and the target force (CVT). Area between the force curve and the target force line (Area) was also calculated. For the older adults we explored reliability using intraclass correlation coefficient (ICC) and agreement using standard error of measurement (SEM), limits of agreement (LOA) and smallest real difference (SRD).
A systematic improvement in handgrip steadiness was found between sessions for all measures (CVM, CVT, Area). CVM and CVT at 5% of MVC showed good to high reliability, while Area had poor reliability for all percentages of MVC. Averaged ICC for CVM, CVT and Area was 0.815, 0.806 and 0.464, respectively. Averaged ICC on 5%, 10%, and 25% of MVC was 0.751, 0.667 and 0.668, respectively. Measures of agreement showed similar trends with better results for CVM and CVT than for Area. Young adults had better handgrip steadiness than older adults across all measures.
The CVM and CVT measures demonstrated good reproducibility at lower percentages of MVC using the WBB, and could become relevant measures in the clinical setting. The Area measure had poor reproducibility. Young adults have better handgrip steadiness than old adults.
力量稳定性是衡量控制肌肉紧张度能力的一种量化指标。它是功能表现的独立预测指标，并且已表明与中风后不同程度的运动障碍密切相关。尽管其具有临床相关性，但很少有研究评估测量力量稳定性的有效性。本研究的目的是探讨握力稳定性的可重复性，并评估稳定性方面的年龄差异。
采用重测设计，两次测试间隔七天，研究评分者内的可重复性（即评分在不同场合给出一致结果的程度）。招募了10名年轻人和30名老年人，使用任天堂Wii平衡板（WBB）在最大自主收缩（MVC）的5%、10%和25%水平测试握力稳定性。根据产生的平均力（CVM）和目标力（CVT）计算变异系数。还计算了力曲线与目标力线之间的面积（面积）。对于老年人，我们使用组内相关系数（ICC）探索可靠性，并使用测量标准误（SEM）、一致性界限（LOA）和最小真实差异（SRD）评估一致性。
所有测量指标（CVM、CVT、面积）在各次测试之间握力稳定性均有系统性改善。MVC的5%时的CVM和CVT显示出良好到高度的可靠性，而对于所有MVC百分比，面积的可靠性较差。CVM、CVT和面积的平均ICC分别为0.815、0.806和0.464。MVC的5%、10%和25%时的平均ICC分别为0.751、0.667和0.668。一致性测量显示出类似趋势，CVM和CVT的结果优于面积。在所有测量指标上，年轻人的握力稳定性均优于老年人。
使用WBB在较低百分比的MVC时，CVM和CVT测量显示出良好的可重复性，并且可能成为临床环境中的相关测量指标。面积测量的可重复性较差。年轻人的握力稳定性优于老年人。
