Differences in Isometric Neck Muscle Strength Between Healthy Controls and Women With Chronic Neck Pain: The Use of a Reliable Measurement

Abstract

Cagnie B, Cools A, De Loose V, Cambier D, Danneels L. Differences in isometric neck muscle strength between healthy controls and women with chronic neck pain: the use of a reliable measurement. Objectives: To determine the intra- and interrater reliability of the Biodex isokinetic dynamometer to measure the maximal isometric strength of the cervical flexors and extensors, to develop an age- and sex-based normative database in a healthy population, and to evaluate the differences in neck strength between women with chronic neck pain and healthy controls. Design: Cross-sectional. Setting: Physical and rehabilitation medicine department. Participants: Ninety-six healthy volunteers (4 age groups: 20-29, 30-39, 40-49, 50-59y; each consisting of 12 men and 12 women) and 30 women with chronic neck pain. Interventions: Not applicable. Main Outcome Measures: Peak isometric strength of the cervical muscles was tested for flexion and extension by using the Biodex isokinetic dynamometer. The intra- and interrater reliability of the protocol was evaluated in 12 volunteers. Results: The reliability for strength was high for both flexion and extension (intraclass correlation coefficient, .92-.96). The mean peak torque for flexion and extension was significantly higher in men (24Nm, 36.4Nm, respectively) compared with women (16.6Nm, 26.5Nm, respectively) (P