The group of knee flexors muscles insert on the tibia at an angle of 17 and insert 0.06 m from the axis of rotation at the knee.

The group of knee flexors muscles insert on the tibia at an angle of 17° and insert 0.06 m from the axis of rotation at the knee. How much force must the knee flexors exert to produce an angular acceleration at the knee of 5 rad/s2 , given that the lower leg and foot together have a mass of 6.3 kg and radius of gyration of 0.21 m?