Changes in Neck and Shoulder Muscles Fatigue Threshold When Using a Passive Head/Neck Supporting Exoskeleton During...

Area of Science:

• Ergonomics and Human Factors
• Biomechanics
• Occupational Health

Background:

• Overhead work tasks pose significant risks for neck and shoulder musculoskeletal disorders.
• Excessive strain on neck and shoulder muscles and joints is a primary concern in overhead labor.
• Understanding fatigue mechanisms is crucial for developing effective interventions.

Purpose of the Study:

• To evaluate the impact of a head/neck supporting exoskeleton (HNSE) on muscle fatigue.
• To determine the effects of HNSE on the electromyographic fatigue threshold (EMGFT) in neck and shoulder muscles.
• To assess HNSE effectiveness during a simulated overhead work task.

Main Methods:

• Fourteen healthy males performed a repetitive overhead task to exhaustion.
• Participants completed the task with and without the HNSE at varying neck extension angles (40% and 80% of maximum).
• Electromyographic (EMG) signals from neck and shoulder muscles were analyzed to determine EMGFT.

Main Results:

• The HNSE significantly increased EMGFT in sternocleidomastoid (SCM) and upper trapezius (UTR) muscles.
• Fatigue onset was delayed in SCMR, SCML, and UTR muscles when using the HNSE.
• No significant effect on deltoid or left trapezius EMGFT was observed; neck angle had no significant impact.

Conclusions:

• The HNSE effectively delays fatigue onset in specific neck muscles, indicating its potential as an ergonomic intervention.
• Findings support the use of EMGFT to assess the efficacy of exoskeletons in reducing occupational musculoskeletal disorder risk.
• Further research is recommended to explore HNSE effects in diverse tasks and conditions.