Abstract
Background. The ability to dynamically control fingertip force vector magnitude and direction is critical for dexterous manipulation. We quantified the dynamic control of fingertip forces to examine how dexterous manipulation declines with age. Methods. The strength-dexterity (SD) test measures fingertip forces during compression of a slender spring prone to instability and buckling. The greatest sustained compression (designed to be under 3 N), and force dynamics therein, have been shown to be simple and quick measures of dynamic dexterous manipulation ability. We measured pinch strength and strength-dexterity test in a cross-sectional population of 98 people from 18 to 89 years of age. Results. Dexterous manipulation ability is poorer at older ages, beginning in middle age (p <. 001), with greater decline past 65 years of age. Fingertip force dynamics during spring compression and stabilization show a deterioration of neuromuscular control with age. Importantly, this novel detection of decline in dynamic manipulation ability is not correlated with, and thus cannot be entirely explained by, the known decline in pinch strength. We also measured standardized tests of dexterity in participants older than 45, and discuss how the strength-dexterity test uniquely captures features of sensorimotor capabilities for dexterous manipulation in this adult population. Conclusions. Starting in middle age, changes in the functional interactions among sensory, motor, and neural capabilities result in measurably poorer dynamic dexterous manipulation. This deterioration of neuromuscular control motivates and enables future studies to understand the physiological bases for this functional decline so critical to activities of daily living and quality of life.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1139-1145 |
| Number of pages | 7 |
| Journal | Journals of Gerontology - Series A Biological Sciences and Medical Sciences |
| Volume | 69 |
| Issue number | 9 |
| DOIs | |
| State | Published - Sep 2014 |
Funding
Supplementary Material Supplementary material can be found at: http://biomedgerontology. oxfordjournals.org/ Funding This work was funded in part by a grant from the National Institute on Disability and Rehabilitiation Research Grant (RERC 84-133E2008-8), National Science Foundation Grant (EFRI-COPN 0237258), and National Institutes of Health Grants (AR050520 and AR052345 to F.V.C.). However, those contents do not necessarily represent the policy of the Department of Education, and you should not assume endorsement by the Federal Government.
Keywords
- Aging
- Dexterous manipulation
- Dynamical analysis
- Middle age
- Pinch strength
ASJC Scopus subject areas
- General Medicine