Finger force coordination underlying object manipulation in the elderly - a mini-review.
BACKGROUND
A decline in manual dexterity is a common phenomenon in elderly individuals. Often, simple daily activities such as handling coins and preparing meals become challenging. A substantial decline in manual dexterity may impact one's ability to live independently. Thus, understanding the underlying causes of these impairments is essential. Considerable attention has been given to the regulation of fingertip forces during object grasp, lift and transport in the elderly.


OBJECTIVE
Here we review studies on fingertip force coordination in the elderly, with an emphasis on the relationship between the degree of change in elderly grip force control and the nature of the tasks performed.


METHODS
A literature search was performed using Medline, Pubmed, and Web of Science electronic databases covering studies from 1985 to 2009, inputting combinations of the following key words: grip force, grasp force, fingertip forces, precision grip, aging, elderly, and hand motor control.


RESULTS
Studies show a consistent elevation in grip force magnitudes that may easily lead to fatigue. These force increases may represent a compensation for increased skin slipperiness or a reduction in tactile information. In contrast, anticipatory grip force control (planning) remains relatively intact. Age-related changes in anticipatory control seem to emerge only during more complex tasks.


CONCLUSIONS
The relationship between task complexity and degree of age-related changes suggests that results from simple, laboratory-based tasks may only partially explain impairments observed during the performance of activities of daily living, since the latter ones are typically more complex. A better understanding of impaired manual dexterity experienced by elderly individuals could be achieved by expanding experimental paradigms so that they more closely resemble the complexities encountered in functional daily tasks. Subsequently, these findings could be used in clinical settings to develop treatment approaches that consider grasp control in the context of behaviorally meaningful tasks.
Diermayr
Gudrun
G
Department of Biobehavioral Sciences, Teachers College, Columbia University, New York, N.Y., USA.
McIsaac
Tara L
TL
Gordon
Andrew M
AM
D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D001696:Biomechanical Phenomena; D025461:Feedback, Physiological; D005260:Female; D005385:Fingers / Q000502:physiology; D018737:Hand Strength / Q000502:physiology*; D006801:Humans; D008297:Male; D009142:Musculoskeletal Physiological Phenomena; D011597:Psychomotor Performance / Q000502:physiology*