Ambient temperature and neck EMG with +Gz loading on a trampoline

Area of Science:

• Aerospace Medicine
• Occupational Health
• Biomechanics

Background:

• Fighter pilots experience higher rates of neck pain and occupational disorders, potentially linked to cold exposure.
• A hypothesis suggests cold-induced muscle strain contributes to in-flight neck injuries.

Purpose of the Study:

• To quantify pre-flight skin cooling in fighter pilots.
• To assess neck muscle strain under Gz loading at varying temperatures.

Main Methods:

• Measured skin temperature (Tskin) of 14 subjects before flight and in a -14°C cockpit.
• Recorded electromyography (EMG) activity of neck muscles (sternocleidomastoid, cervical erector spinae, trapezoid, thoracic erector spinae) during exercises at -2°C and +21°C.

Main Results:

• Significant Tskin decrease observed over trapezoids before takeoff (30.1°C to 27.8°C).
• Cold conditions increased muscle strain: +11.0% (SCM), +14.9% (CES), +3.7% (TRA), -1.7% (TES).
• Cervical muscles (SCM, CES) showed statistically significant increases in strain; a 2.6% strain increase per 1°C Tskin drop over SCM.

Conclusions:

• Pre-flight superficial neck cooling is significant.
• Cold-induced muscle loading elevates EMG activity.
• Cervical muscles experience substantial strain increases, suggesting a link to cold-induced muscle strain during in-flight Gz loading.