HSBH3014 Lecture Notes - Lecture 7: Sony Max, Disneymania, Whole Body Vibration
22 Aug 2018
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Introduction: in the usa, 500,000 workers suffer over-exertion injuries per year, 60% involve lifting, 20% involve pushing & pulling. 49: body stressing causes a lot of injuries - particularly carrying & lifting 49% Page 6: aim to reduce the occurrence of back injury, muscle & joint = 87% Dynamics of lifting: most compressive forces and shear forces (depending on the angle the body is at, compression if standing/sitting up, shear forces if leaning back or forward (shear forces depend on angle the spine is at) 20kg weight in hand: compression force is 4x body weight, shear is ~90% body weight. Peak moment is around 50-60% - largest moment on body. This one is recommended because can withstand shear loads (spine is angled) Pressure is a lot less in knees bent & back straight. B upright stance with 10kg in each hand. Back straight will increase stress the most (worst) Increased but not by much compared to no weight.
