Neck Kinematics and Electromyography While Wearing Head Supported Mass During Running

Area of Science:

• Aerospace Medicine
• Sports Science
• Biomechanics

Background:

• Advanced combat helmets (ACH) with night-vision goggles (NVG) are essential for military personnel.
• Head-supported mass (HSM) from this equipment can cause head and neck injuries.
• Understanding the impact of HSM on neck musculature is crucial for preventing chronic issues.

Purpose of the Study:

• To investigate the effects of head-supported mass (HSM) on neck muscle fatigue.
• To analyze muscle activation and kinematic changes during strenuous activity with ACH and NVG.
• To determine the potential for chronic stress and injury due to prolonged HSM exposure.

Main Methods:

• Subjects ran on a treadmill wearing an ACH, with and without NVG.
• Electromagnetic sensors and EMG electrodes measured kinematic data and muscle activation (sternocleidomastoid, upper trapezius, paraspinal).
• Data was collected during a protocol simulating fatigue until exhaustion.

Main Results:

• Significant differences in muscle activation were observed in the upper trapezius and sternocleidomastoid muscles from pre-fatigue to absolute fatigue.
• No significant changes were found in kinematic variables during the protocol.
• Fatigue affected bilateral neck flexors, rotators, and contralateral neck extensors.

Conclusions:

• Head-supported mass (HSM) significantly fatigues key neck muscles, including flexors, rotators, and extensors.
• This fatigue pattern suggests a risk of chronic stress and injury in tactical athletes using ACH with NVG.
• Further research may inform strategies to mitigate these risks.