Changes in neuromuscular function due to intermittently increased workload during repetitive work in cold conditions

Area of Science:

• Occupational Health
• Ergonomics
• Physiology

Background:

• Cold environments can negatively impact neuromuscular function during repetitive tasks.
• Understanding the effects of cold on muscle activity and fatigue is crucial for workplace safety.

Purpose of the Study:

• To investigate how repetitive work in cold conditions affects electromyographic (EMG) gaps.
• To determine if altering work intensity can reverse cold-induced neuromuscular deterioration.

Main Methods:

• Simulated sausage packing at 19°C and 4°C to measure EMG gaps in eight upper-extremity muscles.
• Assessed continuous light work (Cwork) versus intermittent increased workload (Iwork) at 4°C, monitoring EMG gaps, median frequency, EMG activity, and wrist flexion maximal voluntary contraction (MVC).

Main Results:

• Cold exposure decreased EMG gaps in seven muscles.
• Intermittent work (Iwork) showed more EMG gaps in forearm flexors and extensors compared to continuous work (Cwork).
• Wrist flexion MVC decreased in both Cwork and Iwork conditions, indicating muscle fatigue.

Conclusions:

• Cold-induced reduction in EMG gaps and increased muscle strain can be partially restored by intermittently increasing workload.
• Breaking monotonous work cycles may mitigate negative effects of cold on neuromuscular function.