Effects of Sensory Deficit on Phalanx Force Deviation During Power Grip Post Stroke

ABSTRACT

The effect of sensory deficits on power grip force from individual phalanges was examined. The authors found that stroke survivors with sensory deficits (determined by the Semmes-Weinstein monofilament test) gripped with phalanx force directed more tangential to the object surface, than those without, although both groups had similar motor deficits (Chedoke-McMaster and Fugl-Meyer), grip strength, and skin friction. Altered grip force direction elevates risk of finger slippage against the object thus grip loss/object dropping, hindering activities of daily living. Altered grip force direction was associated with altered muscle activation patterns. In summary, the motor impairment level alone may not describe hand motor control in detail. Information about sensory deficits helps elucidate patients' hand motor control with functional relevance.

Keywords:

• EMG
• hand
• power grip
• sensory deficit
• stroke

Acknowledgments

The authors would like to thank Dr. Thomas Armstrong and Mr. Charles Woolley for their assistance in developing the custom-made grip dynamometer.

Funding

This study was supported by funding from an American Heart Association Midwest Affiliate Predoctoral Fellowship 12PRE9320004, a Grant-In-Aid award from the American Society of Biomechanics, the University of Wisconsin-Milwaukee Research Growth Initiative, and the Mary E. Switzer Distinguished Fellowship from the National Institute on Disability and Rehabilitation Research grant number H133F110005. However, those contents do not necessarily represent the policy of the Department of Education, and you should not assume endorsement by the Federal Government. Also, this project was supported by the National Center for Advancing Translational Sciences, National Institutes of Health, through Grant Number 8UL1TR000055. Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the NIH.