Precision in isometric precision grip force is reduced in middle-aged adults

Area of Science:

• Neuroscience
• Motor Control
• Human Aging

Background:

• Aging is associated with changes in motor control and grip force regulation.
• Understanding age-related alterations in precision grip is crucial for identifying early signs of motor decline.

Purpose of the Study:

• To investigate age-related changes in the control of precision grip in healthy adults.
• To quantify the impact of age on force regulation during ramp-and-hold tasks.

Main Methods:

• 29 healthy adults (21-67 years) performed a visually guided, isometric precision grip ramp-and-hold force-tracking task.
• Target forces were set at 3, 6, and 9 Newtons (N).
• Precision and performance of force regulation were quantified, analyzing errors during ramp and hold phases, force onset, and force slope.

Main Results:

• Larger errors in force regulation were observed during the ramp phase compared to the hold phase.
• Age positively correlated with increased error at the lowest force level (3 N) in both phases.
• Middle-aged subjects exhibited earlier force onsets, and the force slope during the ramp decreased with increasing age.

Conclusions:

• Precision in low grip force control declines in middle age.
• Individuals may alter force generation strategies to compensate for subtle motor system changes before grip strength diminishes.