Part 1: Determine the force in the Bicep muscle; refer to Figure 1 at right and

Question

Part 1: Determine the force in the Bicep muscle; refer to Figure 1 at right and assumptions below Biceps Radius W Assumptions d1 - bicep insertion point is 0.63" from the pivot point (elbow joint) d2 - length of forearm to center of gravity of W is 15". W= 10 lbs Humerus F1 Forearm A. Solve for F1 when the forearm is parallel to the ground. (angle = 0) as shown in Figure 1 d1 d2 B. Assume you are doing a bicep curl where your upper arm remains fixed and the elbow joint is rotated from 80 degrees to - 60 degrees as shown in Figure 2 Figure 1 -forces in bicep when holding weight Use MatLab to solve for F1 as the elbow is rotated through the range of motion described in 10 degree increments. For purposes of problem simplification, assume that d1 remains constant through this rotation and F1 and F2 remain vertical only forces. Flex forearm to 80 degrees from horizontal eps Plot Force (F1) as a function of degrees of rotation. The graph and appropriate labels should be included in your script file RadiusW Humerus Using this simplified model, where is the force the greatest? Formulas Moment (M) = F * d Extend forearm to- 60 degrees from horizontal For equilibrium M = 0 in each direction Figure 2-forces in bicep when doing bicep curl

Explanation / Answer

2) In this case, we solved the problem without writing the equations of equilibrium.

For reference, these equations are:

summation (Fx) = - T1*cos60 + T2*cos30 = 0 ====> T1 = 1.732*T2

summation (Fy) = T1*sin60 + T2*sin30 - mg = 0

  1.732*T2*0.866 + T2*0.866 - 100*9.81 = 0 =====> T2 = 414.64 N

Then T1 = 414.64*1.732 = 718.16 N

Related Questions

Navigate

• Browse (All)
• Browse P
• Subjects

---