Misfingering by Instrumentalists used as a Paradigm for Focal Dystonia in PC Workers

Abstract

Focal dystonia (FD) - a neuromuscular disorder - severely interferes with occupational activities – moreover, it may be an early Multiple Sclerosis symptom (Yücesan et al., 2000) - Focal dystonia of hand and fingers, described as an imbalanced tension of their different muscles, leads to painful, impaired and often aberrant motions (Van Zwieten et al., 2008) - Normal coordinated finger flexion becomes clear by a kinematic model (Sholukha et al., 1998) - Such a model can also be used to analyze uncoordinated finger movement patterns, e.g. those visible after long standing peripheral neuropathies (Van Zwieten et al., 2008) - An example of such a peripheral neuropathy is the “intrinsic minus” hand, caused by chronic neurodegeneration of n. ulnaris, which innervates most of intrinsic hand muscles - Fingers of “intrinsic minus” hands are characterized by o.a. hyperextension of their metacarpophalangeal joints, simultaneous with flexion of the both interphalangeal joints - Muscle tension imbalances in focal dystonia too, will produce “intrinsic minus” patterns - As focal dystonia in instrumentalists’ hands also presents itself with “intrinsic minus” patterns (Van Zwieten et al., 2009), similar patterns may be seen in PC-workers