On-track Measurements of Neck Movements and Muscle Activity during Motocross Sessions with or without Neck Brace

This work analyse the movements and the muscular activity during motocross sessions and how a neck brace influence both. These movements are measured in terms of angles using two Biometrics (R) angular sensors (one for bi-planar flexion and one for torsion); the muscle activity is registered using four pairs of electrodes (muscle selected: Sterno-Cleido-Mastoid left and right, Trapezium left and right). From the results obtained, we can conclude that the pilot wants to focus the attention to the next jump or obstacle while accelerations of different nature are acting on the neck, therefore isometric contractions are predominant. The fact that the brace did not reduce the rotational range of motion is a positive result because the pilot field of view is not modified which is a safety requirement. According to the evidence of a fatigue effect, the brace is useful not only to protect the pilot during accidents but also as a supporting device during driving sessions.