Consider a person serving a platter of hot food to their family who is gathered around a table. When holding theplatter, the person can choose how to hold the platter in front of them and would like compare the differences between position 1 and position 2 as shown below. In position 1, the shoulder is at 0 degrees while the elbow is at 90 degrees and in position 2, the arm is flexed as shown. a.) Consider the elbow joint and draw free body diagrams for each of the positions shown, including gravitational forces (consider the weight of the combined forearm and hand), elbow flexor forces, and the joint contact force. b.) Use the information provided below to solve for the magnitude of the elbow flexor force (in Newtons) for positions 1 and 2, the magnitude of the joint contact force (in Newtons), and the angle that the joint contact force makes with respect to the horizontal axis. • The platter of food weighs 7 lbs; the person weighs 175 lbs, and the person is 5’8” tall. • θ = 130 degrees and the insertion point of the elbow flexor is 3.5 cm away from the elbow joint. • Based on anthropometric data, the combined weight of the forearm and hand make up 2.2% of the total body weight. • Additional anthropometric data is provided in Figure 2 to help you determine the moment arms of the forearm + hand (consider them one segment) and the platter. Assume that the platter is held in the middle of the hand.
Consider a person serving a platter of hot food to their family who is gathered around a table. When holding theplatter, the person can choose how to hold the platter in front of them and would like compare the differences between position 1 and position 2 as shown below. In position 1, the shoulder is at 0 degrees while the elbow is at 90 degrees and in position 2, the arm is flexed as shown.
a.) Consider the elbow joint and draw free body diagrams for each of the positions shown, including gravitational forces (consider the weight of the combined forearm and hand), elbow flexor forces, and the joint contact force.
b.) Use the information provided below to solve for the magnitude of the elbow flexor force (in Newtons) for positions 1 and 2, the magnitude of the joint contact force (in Newtons), and the angle that the joint contact force makes with respect to the horizontal axis.
• The platter of food weighs 7 lbs; the person weighs 175 lbs, and the person is 5’8” tall.
• θ = 130 degrees and the insertion point of the elbow flexor is 3.5 cm away from the elbow joint.
• Based on anthropometric data, the combined weight of the forearm and hand make up 2.2% of the total body weight.
• Additional anthropometric data is provided in Figure 2 to help you determine the moment arms of the forearm + hand (consider them one segment) and the platter. Assume that the platter is held in the middle of the hand.
force analysis of elbow flexors. In anatomical mechanics, the forearm and elbow joint are often considered as a lever system whose fulcrum is located at the elbow joint. In contrast with mechanical leverage, the anatomical lever system usually has more than one unknown input force for the desired output performance. These forces are internal or muscle forces. There are three elbow flexors, involved in elbow flexion motion: (1) the brachioradialis, (2) the brachialis, and (3) the biceps. A number of elbow total replacements are available at present; however, the literature on biomechanical analysis of elbow motion, particularly the kinetic study, is scant.
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