Research Department, Department of Rheumatology, Rehabilitation Centre Valens, 7317 Valens, Switzerland.
Phys Ther. 2012 Sep;92(9):1130-40. doi: 10.2522/ptj.20110473. Epub 2012 May 31.
Functional capacity evaluation (FCE) requires determination of effort by observation of effort indexes for performance interpretation. Waddell signs have been shown to be associated with decreased functional performance. Whether determination of effort by observational criteria and Waddell sign testing can be used interchangeably to interpret lifting performance is unknown.
The purposes of this study were to assess the concurrent validity of submaximal effort and Waddell signs and to determine whether these contribute independently to lifting performance.
This investigation was an analytical cross-sectional study.
A total of 130 people who had chronic nonspecific low back pain and were referred for fitness-for-work evaluation were included. Physical effort was determined on the basis of observational criteria for lifting from floor to waist, lifting from waist to shoulder, and horizontal lifting during FCE. A second assessor conducted Waddell sign testing. The concurrent validity of Waddell signs and submaximal effort was assessed by calculating sensitivity and specificity. Hierarchical regression analysis was used to determine the contributions of Waddell signs and submaximal effort to lifting performance. Age and sex were covariates.
The FCE assessor found a low sensitivity of Waddell signs for submaximal effort determination. Between 53% and 63% of the participants who were classified as showing submaximal effort had Waddell signs. Waddell signs and submaximal effort were independent contributors to lifting performance. The contribution of submaximal effort was larger than that of Waddell signs, as shown by 20% to 29% higher explained variance in lifting performance when submaximal effort was added to the model first versus 3% to 6% higher explained variance when Waddell signs were added first.
Assessor variability could have influenced the study results.
In people with chronic nonspecific low back pain, Waddell sign testing and determination of physical effort by observational criteria should not be used interchangeably to interpret lifting performance during FCE.
功能能力评估（FCE）需要通过观察绩效解释的努力指标来确定努力程度。Waddell 征已被证明与功能表现下降有关。通过观察标准和 Waddell 征测试来确定努力程度是否可以互换使用来解释举重表现尚不清楚。
本研究的目的是评估亚最大努力和 Waddell 征的同时效度，并确定它们是否可以独立地对举重表现做出贡献。
本研究为分析性横断面研究。
共纳入 130 名患有慢性非特异性下腰痛并被转介进行工作能力评估的人。在 FCE 中，通过从地板到腰部、从腰部到肩部以及水平举重的观察标准来确定体力劳动。第二位评估员进行了 Waddell 征测试。通过计算敏感性和特异性来评估 Waddell 征和亚最大努力的同时效度。使用分层回归分析确定 Waddell 征和亚最大努力对举重表现的贡献。年龄和性别为协变量。
FCE 评估员发现 Waddell 征对确定亚最大努力的敏感性较低。在被归类为表现出亚最大努力的参与者中，有 53%至 63%出现 Waddell 征。Waddell 征和亚最大努力是举重表现的独立贡献者。亚最大努力的贡献大于 Waddell 征，当首先向模型中添加亚最大努力时，举重表现的解释方差增加了 20%至 29%，而当首先添加 Waddell 征时，解释方差增加了 3%至 6%。
评估者的变异性可能影响研究结果。
在患有慢性非特异性下腰痛的人群中，在 FCE 期间解释举重表现时，不应将 Waddell 征测试和通过观察标准确定体力劳动互换使用。
