THE MECHANISM OF FINGER CONTROL, BASED ON ELECTROMYOGRAMS AND LOCATION ANALYSIS

Abstract

The mechanism of finger control is analyzed. Location analysis indicates the exact location of tendons in relation to the bony structure of the finger and describes the possibilities and limits of motion. Electromyography determines the contribution of the active contraction of muscle to movements of the system. Viscoelastic forces fulfill those force requirements imposed by location analysis but not explained by the electromyographic indications of muscule contraction. The interpretation results in the classification of coordinated finger motions into 4 categories; class a (clawing motions), in which the extrinsics provide the primary control: class-b (opening motions) in which extensor digitorum and lumbricalis provide active force and the flexor-digitorum profundus supplies viscoelastic force; class-c (reciprocal motions), in which interossei and lumbricalis both contribute actively, and flexor digitorum-profundus provides viscoelastic force; and class-d (closing motions), in which active force is contributed by the flexor-digitorum-profundus and extensor-digitorum, while the intrinsics provide viscoelastic force.