In a simplified version of the musculature action in leg raises, the abdominal m
ID: 2209574 • Letter: I
Question
In a simplified version of the musculature action in leg raises, the abdominal muscles pull on the femur (thigh bone) to raise the leg by pivoting it about one end, as shown in the figure below . When you are lying horizontally, these muscles make an angle of approximately 5.00 degrees with the femur, and if you raise your legs, the muscles remain approximately horizontal, so the angle theta increases. We shall assume for simplicity that these muscles attach to the femur in only one place, 10.0 cm from the hip joint (although, in reality, the situation is more complicated). For a certain 80.0 kg person having a leg 90.0 cm long, the mass of the leg is 14.5 kg and its center of mass is 50.0 cm from his hip joint as measured along the leg. If the person raises his leg to 59.0 degrees above the horizontal, the angle between the abdominal muscles and his femur would also be about 59.0 degrees. With his leg raised to 59.0 degrees, find the tension in the abdominal muscle on each leg.Explanation / Answer
yes