Proximal forearm extensor muscle strain is reduced when driving nails using a shock-controlled hammer

Area of Science:

• Occupational health
• Biomechanics
• Ergonomics

Background:

• Repetitive hammer use is a known cause of musculoskeletal injuries.
• Forearm muscle strain, inflammation, and edema are common adverse responses.

Purpose of the Study:

• To investigate if a shock-control hammer reduces forearm muscle strain.
• To assess physiological responses like inflammation and edema after hammer use.

Main Methods:

• Fifty volunteers used wood-handle, steel-handle, or shock-control hammers.
• Magnetic resonance imaging (MRI) assessed forearm muscle inflammation and edema.
• Electromyogram (EMG) signals measured grip exertion and muscle fatigue.

Main Results:

• The shock-control hammer demonstrated 40% greater kinetic energy upon impact.
• Significantly less proximal extensor muscle edema was observed with the shock-control hammer immediately after use (p<.05).
• Grip force estimations were similar across all hammer types.

Conclusions:

• Isolating handle shock with a shock-control hammer can mitigate strain in proximal forearm extensor muscles.
• This suggests a potential reduction in occupational musculoskeletal injury risk.