Confiabilidade intra e inter avaliador da dinamometria manual para avaliação da força muscular isométrica em pacientes com dor cervical crônica inespecífica

Abstract

Chronic neck pain is considered the third most common cause of disability worldwide among musculoskeletal conditions. Among its repercussions, there is ample evidence that these individuals present with cervical muscle weakness. Therefore, muscle strength tests are important in clinical practice for its measurement, and hand-held dynamometry has proven to be an accessible alternative for measuring isometric muscle strength. Despite this, its reliability has not yet been specifically tested in the chronic neck pain population, with an adequate sample size, considering the COSMIN (Consensus-based Standards for the Selection of Health Measurement Instruments) recommendations, and that has covered the four directions of cervical muscle strength (flexion, extension, and right and left lateral flexion). Objective: To investigate the intra- and inter-rater reliability, determine the standard error of measurement (SEM) and the minimum detectable change (MMD) of hand-held dynamometry for assessing isometric muscle strength in patients with nonspecific chronic neck pain. Methods: Fifty participants aged 18 years or older with chronic nonspecific neck pain were recruited. Isometric cervical muscle strength tests were performed by two evaluators with a 10-minute interval between them (inter-evaluator), and the procedure was repeated 5 to 7 days after the first visit (intra-evaluator). Intra-evaluator (ICC3, k) and inter-evaluator (ICC2, k) reliability analysis was performed using the intraclass correlation coefficient (ICC) test. The SEM was calculated by the formula SEM = SD × √ (1 − ICC) and the MMD by MMD = 1.96 × √2 × SEM. Results: Intra- (flexion = 0.95; left lateral flexion = 0.91; right lateral flexion = 0.94; extension = 0.89) and inter-rater (flexion = 0.93; left lateral flexion = 0.92; right lateral flexion = 0.95; extension = 0.95) reliability was excellent for all movements. The intra-rater SEM values ranged from 0.67 to 1.17 and inter-rater values from 0.83 to 1.05, while the intra-rater MMD ranged from 1.85 to 3.25 and inter-rater values from 2.30 to 2.92. Conclusion: Portable hand-held dynamometry demonstrated excellent reliability in assessing isometric muscle strength in patients with chronic neck pain. The SEM and MDC values found in this study can help clinicians monitor patients over time.