The following data estimated:
|
Segment
|
Length(cm)
|
Weight(N)
|
Center of mass from proximal joint(cm)
|
|
Upper arm
|
35
|
25
|
15
|
|
Forearm
|
25
|
15
|
10
|
|
Hand
|
20
|
5
|
10
|
Question 1. Given the upper extremity posture below, calculate the resultant forces and moments at the wrist, elbow and shoulder for pulling 200N with the forearms supinated, use a 2-D static analysis. Assume the force is exerted at the center of mass of the hand, perpendicular to the hand.
Question 2. Assume that biceps exerts force at an angel of 150° with respect to the forearm and the insertion for biceps is 5 cm from the elbow. Calculate Fm the biceps muscle force, and R, the joint reaction force at the elbow for the situation depicted in problem#1. Use a 2D static analysis.
Question 3. Using a 2D dynamic analysis of the above situation( at the instant in the time shown), calculate Fm, the biceps muscle force. Assume that the moment of inertia of the forearm, hand and load system about the elbow is 3 kg-m2 and that the instantaneous angular acceleration of this system is 10 rad/sec2.