Research Methods and Progress of Patellofemoral Joint Kinematics: A Review

Figure 11

Patellofemoral arm and moment of force during flexion or extension. Patellofemoral arm of force is defined as the distance from the resultant force of the quadriceps to FHA. Patellofemoral moment of force is defined as the product of the arm of force and the resultant force of quadriceps. F: resultant force of quadriceps, FHA: patellar finite helical axis, L: arm of resultant force of quadriceps, and M: moment of resultant force of quadriceps (F × L).