2-facility requires lifting heavy boxes from a pallet. The following posture is observed where the torso flexion is 30 (i.e., assume a= 30) in lifting a box. Assume this is a symmetrical lift where both arms are in identical postures. CUTTING PLANE HORIZONTAL FCOMP FMUSC X -b -h F SHEAR mgBw Dimension Back muscle moment arm at L5/S1 Mass of the torso and the head Mass of both arms and both hands Horizontal distance from L5/S1 to the mass center of the upper body (including torso, head, arms, hands) Horizontal distance from L5/S1 to the mass center of the box Value 5 cm 30 kg 15 kg 23 cm 55 cm a) (6 pts) Suppose the mass of all items inside the box is 17 kg, and the mass of an empty box is 1kg. Calculate the back-muscle force required to hold the full box in this posture. b) (5 pts) Calculate the disc compression force at L5/S1 in the situation described above. c) (2 pts) Based on your result from b), answer the following question: Is the L5/S1 disc compression force higher or lower than the NIOSH action limit or maximum permissible limit? Justify your answer with the related numbers for both limits. d) (2 pts) When the box is placed in its final position, the worker is standing upright holding the full box, will the disc compression force at L5/S1 most likely increase, decrease, or stay the same when compared to initial lift posture? Briefly explain the reason (no computation needed). 1 e) (2 pts) To reduce the injury potentials, list two recommendations that you have for lifting boxes.