Marras W S, Reilly C H
Department of Industrial and Systems Engineering, Ohio State University, Columbus.
Spine (Phila Pa 1976). 1988 Jun;13(6):661-7.
Many attempts have been made to describe the activity of the internal trunk-loading components (muscles and intra-abdominal pressure) in response to external forces acting on the trunk, as is often the case in the workplace. Most models that describe the activity of these internal components are static and do not consider the time series of events that occurs during performance of a task under dynamic conditions. This research has investigated the time sequence activity of ten trunk muscles and intra-abdominal pressure in ten males as they produced sagittally symmetric maximum trunk extension motions (lifting motions) at different velocities. These exertions include an isometric exertion and isokinetic exertions equal to 25, 50, 75 and 100% of a subject's maximum extension velocity. Several event times were noted for each internal trunk-loading component, and hypothesis tests were performed to determine which of these event times were statistically different from each other under the various motion conditions. This information was used to construct networks of internal trunk-loading activities under the various motion conditions. Time-series events that occur under all conditions, as well as those that changed as a function of velocity, have been identified. This information will be useful for the construction of dynamic internal trunk models, and will facilitate the assessment of dynamic loading of the lumbar spine in the workplace.
人们已经进行了许多尝试，来描述躯干内部负荷组件（肌肉和腹内压）在受到作用于躯干的外力时的活动情况，这在工作场所中是很常见的。大多数描述这些内部组件活动的模型都是静态的，没有考虑在动态条件下执行任务期间发生的事件的时间序列。本研究调查了十名男性在以不同速度进行矢状面对称的最大躯干伸展运动（举重运动）时，十块躯干肌肉和腹内压的时间序列活动。这些用力包括等长用力和等速用力，等速用力分别相当于受试者最大伸展速度的25%、50%、75%和100%。记录了每个躯干内部负荷组件的几个事件时间，并进行了假设检验，以确定在各种运动条件下，这些事件时间中哪些在统计学上彼此不同。这些信息被用于构建各种运动条件下躯干内部负荷活动的网络。已经确定了在所有条件下发生的时间序列事件，以及那些随速度变化的事件。这些信息将有助于构建动态的躯干内部模型，并将有助于评估工作场所中腰椎的动态负荷。
