Reliability of a simple method of measuring isometric neck muscle force.

A new measurement device was constructed to measure the maximal isometric neck muscle forces. In this study the repeatability of the measurements was evaluated in 34 healthy reserve flying conscripts from Finnish Defence Forces. The measurements of the maximal isometric forces were done in four directions: flexion, extension, and right and left lateral flexions. The intraobserver and intraobserver reliability coefficients were calculated for repeated measurements. The system achieved satisfactory repeatability of lateral flexion and extension force measurements. The total variation was small in lateral flexions and extension, and for these directions was only to a small extent dependent on the examiner and the time of measurement.