McGorry Raymond W, Dempsey Patrick G, O'Brien Niall V
Liberty Mutual Research Institute for Safety, 71 Frankland Road, Hopkinton, MA, USA.
Ergonomics. 2004 Dec;47(15):1640-56. doi: 10.1080/00140130412331303894.
The purpose of the study was to investigate factors related to force and postural exposure during a simulated meat cutting task. The hypothesis was that workstation, tool and task variables would affect the dependent kinetic variables of gripping force, cutting moment and the dependent kinematic variables of elbow elevation and wrist angular displacement in the flexion/extension and radial/ulnar deviation planes. To evaluate this hypothesis a 3 x 3 x 2 x 2 x 2 (surface orientation by surface height by blade angle by cut complexity by work pace) within-subject factorial design was conducted with 12 participants. The results indicated that the variables can act and interact to modify the kinematics and kinetics of a cutting task. Participants used greater grip force and cutting moment when working at a pace based on productivity. The interactions of the work surface height and orientation indicated that the use of an adjustable workstation could minimize wrist deviation from neutral and improve shoulder posture during cutting operations. Angling the knife blade also interacted with workstation variables to improve wrist and upper extremity posture, but this benefit must be weighed against the potential for small increases in force exposure.
本研究的目的是调查在模拟切肉任务中与力和姿势暴露相关的因素。假设是工作平台、工具和任务变量会影响握力、切割力矩等相关动力学变量，以及肘部抬高和手腕在屈伸和桡尺偏斜平面内的角位移等相关运动学变量。为了评估这一假设，对12名参与者进行了3×3×2×2×2（表面方向×表面高度×刀片角度×切割复杂度×工作节奏）的受试者内析因设计。结果表明，这些变量可以单独起作用并相互作用，从而改变切割任务的运动学和动力学。参与者在基于生产率的节奏下工作时，会使用更大的握力和切割力矩。工作表面高度和方向的相互作用表明，使用可调节的工作平台可以在切割操作过程中使手腕偏离中立位置的程度最小化，并改善肩部姿势。将刀片倾斜也与工作平台变量相互作用，以改善手腕和上肢姿势，但这种益处必须与力暴露略有增加的可能性相权衡。
