摘要: New tactical ground vehicles developed by the U.S. Army are lower in weight andcapable of higher speeds than their predecessors. This combination produces repetitive mechanical shocks that are transmitted to the soldier primarily ... 展开 New tactical ground vehicles developed by the U.S. Army are lower in weight andcapable of higher speeds than their predecessors. This combination produces repetitive mechanical shocks that are transmitted to the soldier primarily through the seating system. Under certain operating conditions, this exposure poses health and safety threats to the crew as well as performance degradation due to fatigue. The Army Surgeon General urgently required the Medical Research and Materiel Command to develop exposure standards for repetitive impacts that are relevant to the environment of soldiers operating modern tactical vehicles. A five-phase research study was designed to develop a standard for the health hazard assessment of mechanical shock and repeated impact in Army vehicles. The areas of focus were: epidemiology; subjective response; physiology; biochemistry; muscle activity; biomechanics; biodynamic response and modeling; field studies; current standards; and signal processing. An annotated bibliography was generated and the existing literature was summarized. Evidence exists that long-term exposure to vibration accelerates onset of spine disorders, and possibly adversely affect the gastrointestinal and cardiovascular systems. Few human studies have investigated physiological and biochemical responses to repeated impact, and none have investigated recovery. Distinct differences were noted in the mechanism and outcome of acute and chronic injury to the spine caused by exposure to impact and vibration. Few biodynamic models were designed to predict chronic health problems; however, important contributions have been made to understanding tissue stresses. International Organization for Standardization (ISO) guidelines for human response to whole-body vibration do not adequately account for exposure to repeated impacts. 收起