Effect of Sensory Deprivation on Maximal Force Abilities from Local to Non-local Digits

Abstract

The present study investigates the effect of sensory deprivation of the index and middle finger on motor function of all digits during maximal voluntary force production tasks. A total of 27 subjects performed maximal isometric pressing tasks by using different instructed finger combinations. Subjects completed the same tasks in two visits: a control visit when they had normal sensory feedback in all fingers, and an anesthesia visit when digital nerve blocks were performed on their right index and middle fingers. We evaluated three aspects of motor adaptation on both local (anesthetized) and non-local (non-anesthetized) digits during maximal force production: (1) task-relevant and overall force magnitude, (2) force directional application, and (3) digital individuation and force sharing. Our results indicate that selective digital anesthesia resulted in decreased maximal force magnitude, changed direction of force production, and significant changes extended to non-local digits. The motor weakness and inefficiency revealed in the non-local digits implies that sensory information from each digit can be shared across the digits to assist motor execution within the same hand.

Keywords:

• digital anesthesia
• force direction
• force magnitude
• maximal voluntary contraction
• motor deficit
• sensory deprivation

Acknowledgement

The authors thank Gabriella Trovato for assistance in data acquisition scheduling and coordination. They also thank Rosa Nicolas and Maria Nicolas for proof reading and helpful comments on the manuscript. They thank Tracy Campbell and Xianlong Meng, M.E. for assistance in experimental set up.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was partially supported by PSC-CUNY Awards (68854-00 46) and Doctoral Student Research Grant from the City University of New York.