Children's coordination of force output in a pinch grip task
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Updated: Sep 29, 2026
Measurement of Spatial Stability in Precision Grip
Published on: June 4, 2020
Katherine M Deutsch1, Karl M Newell
1Department of Kinesiology, The Pennsylvania State University, University Park, PA 16802, USA.
Insights
Older individuals exhibit better grip force control due to improved use of visual feedback, not reduced sensorimotor noise. This enhances coordination between thumb and index finger.
Area of Science:
- Neuroscience
- Human Motor Control
- Developmental Psychology
Background:
- Sensorimotor system noise influences motor control and inter-digit coordination.
- Age-related differences in motor performance are well-documented but underlying mechanisms require further investigation.
Purpose of the Study:
- To investigate the role of sensorimotor noise in grip force organization and inter-digit coordination across different age groups.
- To determine the influence of visual feedback on age-related differences in pinch grip force control.
Main Methods:
- Isometric pinch grip force task involving thumb and index finger.
- Tested participants aged 6 to 22 years across various force levels (5-35% MVC).
- Compared performance with and without visual feedback to assess its impact.
Main Results:
- Increased age correlated with higher signal-to-noise ratio and enhanced inter-digit coherence under visual feedback.
- Age-related improvements in force control were diminished without visual feedback.
- Sensorimotor noise did not appear to be the primary factor in age-related grip force variability.
Conclusions:
- Age-related improvements in grip force variability are largely attributable to more effective utilization of visual information.
- Intrinsic sensorimotor noise is less critical to age-related performance differences than the ability to process visual feedback.
- Visual feedback plays a crucial role in refining sensorimotor control and inter-digit coordination during force production tasks.
Abstract:
This study examined the role of sensorimotor system noise in the organization of the force output of the thumb and index finger and the coordination between the two digits in an isometric pinch grip force task as a function of age (6, 8, 10, 18-22 years), feedback condition (with and without visual feedback information), and force level (5, 15, 25, and 35% of maximal voluntary force. With increases in age under the visual feedback conditions, the signal-to-noise ratio increased, the sequential structure of the force output signals became more irregular, the degree of coherence between the digits at higher force levels was enhanced, and the digits exhibited a greater degree of coherence across the higher frequencies of the power spectrum at all force levels. However, these age differences were either minimized or eliminated under conditions without feedback. These findings show that the age-related performance differences in grip force variability are primarily due to more effective use of visual information rather than age differences in intrinsic sensorimotor noise.
