Muscular fatigue patterning in power grip assessment

Area of Science:

• Occupational Health and Safety
• Musculoskeletal Biomechanics
• Ergonomics

Background:

• Physical fatigue, particularly muscular fatigue from repetitive hand tasks, is a significant risk factor for occupational injuries.
• Accurate assessment of wrist-hand strength-endurance is crucial for identifying workers at risk.

Purpose of the Study:

• To evaluate a maximal, repetitive, static power grip test for its ability to differentiate between workers with uninjured hands, injured hands, and those feigning exertion.
• To assess the validity and reliability of the power grip protocol in measuring wrist-hand strength-endurance.

Main Methods:

• Utilized a maximal, repetitive, static power grip test protocol.
• Measured power grip muscular force using a force strain gauge as the primary dependent variable.
• Analyzed force fatigue curves and developed an endurance index based on force decrement.

Main Results:

• The power grip protocol demonstrated validity and reliability in estimating wrist-hand strength-endurance.
• Force fatigue curves exhibited both linear and curvilinear patterns across the study groups.
• An endurance index effectively differentiated between uninjured, injured, and insincere exertion groups.

Conclusions:

• The maximal, repetitive, static power grip test is a valid and reliable tool for assessing wrist-hand strength-endurance.
• This testing method can distinguish between genuine and insincere exertions, and identify differences in workers with injured hands.
• Findings support the use of this protocol in occupational health settings to identify injury risks associated with hand grip tasks.