A Flight Helmet-Attached Force Gauge for Measuring Isometric Neck Muscle Strength

INTRODUCTION: Fighter pilots must withstand high G_z-forces that can damage the cervical spine. Strength of the cervical musculature is of vital importance when it comes to preventing these G-induced neck injuries. However, there is very little evidence on valid neck muscle strength measurement methods for fighter pilots. The aim of this study was to examine the validity of a commercial force gauge attached to a pilot's helmet for measuring isometric neck muscle strength.METHODS: A total of 10 subjects performed maximal isometric cervical flexion, extension, and lateral flexion with the helmet-attached gauge and with a weight stack machine, which was used as a reference. Electromyography (EMG) activities were recorded from the right and left sternocleidomastoids and cervical erector spinae muscles during all measurements. Paired t-tests, Pearson correlation coefficient, and Wilcoxon's test were used to analyze the data.RESULTS: Difference of mean force values between the devices was statistically significant in all directions. Pearson correlation coefficient varied between 0.73 and 0.89 and it was highest in cervical flexion. EMG activities were significantly different only in the left CES during flexion.DISCUSSION: The helmet-attached gauge is a valid tool for measuring isometric neck muscle strength and is best used as a means to compare individual differences in strength levels or to track the progress of strength development.Nyländen P, Virmavirta M, Sovelius R, Kyröläinen H, Honkanen T.