The lumbar portion of the human spine supports the entire weight of the upper torso and the force load imposed on it. We consider here the disk (shaded red) between the lowest vertebra of the lumbar region (L5) and the uppermost vertebra of the sacrum re- gion. (a) For the case L = 0, determine the com- pressive force C and the shear force S supported by this disk in terms of the body weight W. The weight W, of the upper torso (above the disk in question) is 68% of the total body weight W and acts at G1. The vertical force F which the rectus muscles of the back exert on the upper torso acts as shown in the figure. (b) Repeat for the case when the person holds a weight of magmitude L = W/3 as shown. State any assumptions. 25 mm W La LA L5 G2 Sacrum 300 mm 50 mm

The lumbar portion of the human spine supports the entire weight of the upper torso and the force load imposed on it. We consider here the disk (shaded red) between the lowest vertebra of the lumbar region (L5) and the uppermost vertebra of the sacrum re- gion. (a) For the case L = 0, determine the com- pressive force C and the shear force S supported by this disk in terms of the body weight W. The weight W, of the upper torso (above the disk in question) is 68% of the total body weight W and acts at G1. The vertical force F which the rectus muscles of the back exert on the upper torso acts as shown in the figure. (b) Repeat for the case when the person holds a weight of magmitude L = W/3 as shown. State any assumptions. 25 mm W La LA L5 G2 Sacrum 300 mm 50 mm

International Edition---engineering Mechanics: Statics, 4th Edition

4th Edition

ISBN:9781305501607

Author:Andrew Pytel And Jaan Kiusalaas

Publisher:Andrew Pytel And Jaan Kiusalaas

Chapter4: Coplanar Equilibrium Analysis

Section: Chapter Questions

Problem 4.97P: The figure shows a wire cutter. Determine the cutting force on the wire at A when the 75-N forces...

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