Activation of Neck and Low-Back Muscles Is Reduced with the Use of a Neck Balance System Together with a Lumbar Support in Urban Drivers

Abstract

Driving is associated with high activation of low-back and neck muscles due to the sittingposition and perturbations imposed by the vehicle. The aim of this study was to investigatethe use of a neck balance system together with a lumbar support on the activation of low-back and neck muscles during driving. Twelve healthy male subjects (age 32±6.71 years)were asked to drive in two conditions: 1) with devices; 2) without devices. During vehicleaccelerations and decelerations root mean square (RMS) of surface electromyography(sEMG) was recorded from the erector spinae, semispinalis capitis and sternocleidomastoidmuscles and expressed as a percentage of maximal voluntary contraction (MVC). The pitchof the head was obtained by means of an inertial sensor placed on the subjects’head. Avisual analog scale (VAS) was used to assess the level of perceived comfort. RMS of thelow back muscles was lower with than without devices during both acceleration and decel-eration of the vehicle (1.40±0.93% vs 29 2.32±1.90% and 1.88±1.45% vs 2.91±2.33%,respectively), while RMS of neck extensor muscles was reduced only during acceleration(5.18±1.96% vs 5.91±2.16%). There were no differences between the two conditions inRMS of neck flexor muscles, the pitch of the head and the VAS score. The use of these twoergonomic devices is therefore effective in reducing the activation of low-back and neckmuscles during driving with no changes in the level of perceived comfort, which is likely dueto rebalancing weight on the neck and giving a neutral position to lumbar segments.