The Challenge of Hand Arm Vibration Syndrome (HAVS)

Abstract

Hand arm vibration syndrome (HAVS) has been defined as a constellation of vascular, neurological, and musculoskeletal signs and symptoms in workers who use hand-held vibrating tools (eg, drills, grinders, saws, or jackhammers); pathological features affect primarily vascular, neurological, and muscle tissues. Researchers have hypothesized changes in central nervous system processing, but no significant somatotopic cortical changes have been found using functional magnetic resonance imaging. Differential diagnosis of HAVS includes a variety of anatomical, circulatory, and vasospastic disorders and was standardized in the Stockholm Workshop classification scale (1987). Available laboratory tests generally are incapable of grading the severity of individual cases, and no protocol reliably distinguishes between psychogenic and organic abnormalities. Some proposed tests are impractical, and multimodality testing is confounded by statistical fallacies. Vascular tests, including the cold provocation tests, correlate poorly with disease staging according to the Stockholm Scale, and plethysmography before and after cold provocation, were found to be unsatisfactory. Job tasks that involve vibrating machines are associated with musculoskeletal symptoms but sorting out the roles and latency periods of vibration, repetitive movements, grip and push factors, and worker postures is imprecise. The AMA Guides to the Evaluation of Permanent Impairment, does not provide directions about rating impairment associated with HAVS, but evaluators can use Chapter 16 The Upper Extremities, basing the rating on motion, neurological, and/or vascular deficits.