A subject in a biomechanics study is performing a knee extension task. At the instant shown when
Question:
A subject in a biomechanics study is performing a knee extension task. At the instant shown when the knee flexion angle is q = 30 o the angular velocity of the hank w = 6 rad/s, and the angular acceleration ? = 150 rad/s 2 . If the shank mass is 5 kg, the distance to the center of mass is 25 cm and the moment of inertia of the lower leg about the center of mass is 0.25 kgm 2 , determine.
a) The knee joint moment.
b) The tension in the patellar tendon if a = 4 cm and ? = 25 o .
c) Calculate the kinetic energy, work and power to go from q = 90 o to 30 o of flexion in a time period of 0.4 sec if the average angular velocity is 3 rad/s and the average knee joint moment was 75 Nm.
Vector Mechanics for Engineers Statics and Dynamics
ISBN: 978-0073212227
8th Edition
Authors: Ferdinand Beer, E. Russell Johnston, Jr., Elliot Eisenberg, William Clausen, David Mazurek, Phillip Cornwell