Reliability of Isometric Strength Measurements in Trunk and Neck Region: Patients With Chronic Neck Pain Compared With Pain-Free Persons

Abstract Scheuer R, Friedrich M. Reliability of isometric strength measurements in trunk and neck region: patients with chronic neck pain compared with pain-free persons. Objective Evaluation of reliability of isometric strength measurements in the neck and trunk region and comparison of these measurements between patients with chronic neck pain and pain-free subjects. Design Nonrandomized controlled trial. Setting Institutional practice. Participants Patients with neck pain (n=53) and pain-free persons (n=42) (mean age ± SD, 49.7±10.74 vs 48.7±12.02; women, 73% vs 71%). Interventions Strength of flexion, extension, and lateral flexion in the neck and trunk were measured. Each participant underwent 2 measurement passes on each of 2 examination days; 3 were performed by the same investigator, 1 by a second. Main Outcome Measures Intrarater (short-term and long-term) and interrater reliability, differences in strength between both groups of probands. Results Reliability in both groups ranged from substantial to almost perfect (intraclass correlation coefficient: patients, .76–.89; control group, .80–.88). The patients' strength in the neck and trunk was significantly below that of the control group ( P