Excessive Shear Force at the Digits May Contribute to Unstable Grip Following Stroke

Stroke is a leading cause of long-term disability in the United States and the third most frequent cause of death, following diseases of the heart and cancer [1]. Of the more than 700,000 Americans who experience a stroke each year [1], two-thirds survive [2]. Currently there are more than five million stroke survivors in the U.S. [1], many of whom have long-term motor and sensory impairments, especially in the arm and hand [3]. Studies report that 69% of patients who were admitted to a rehabilitation unit following stroke have mild to severe upper extremity dysfunction [4], and only 14% to 16% of stroke survivors with initial upper extremity hemiparesis regained near-complete motor function [3,4]. Chronic deficits following stroke are especially prevalent in the hand and therefore diminish the capacity to grasp [5]. Hand grasp has great functional importance for performing activities of daily living. The impairment in grasping significantly lowers stroke survivors’ functional independence.