Although the degree of knee flexion mobility after knee replacement is not as high as normal, the greater the angle, the better, to meet the needs of daily activities. The maximum angle of flexion after knee replacement requires functional exercises in addition to factors related to surgical technique and other factors. A CPM machine can be used to help with exercises during hospitalization, but there is no CPM after discharge, so I will teach the patient’s family how to help the patient practice knee flexion before discharge. The specific method is as follows: take the right knee for example, the patient lies flat with the affected limb near the right side of the bed, the patient’s family stands on the right side of the bed, first grasp the patient’s right ankle with the right hand, place the left hand on the inner and rear side of the thigh above the knee, flex the knee about 30 degrees and gradually flex the hip, flex the hip to about 90 degrees, let the patient’s knee outside against the family’s stomach, the family’s left hand holds the thigh, the right hand on the ankle joint slowly Press. At the beginning of the pressure, the speed can be faster before 90 degrees of knee flexion, and slower when the knee flexion exceeds 90 degrees, until the patient cannot tolerate it. In this way the patient can obtain good mobility in knee flexion (Figs. 2,3). Figure 1 Teaching the patient’s family to help the patient practice knee flexion, this patient is on postoperative day 5 Figure 2 Patient A, knee flexion at the 2-month postoperative review Figure 3 Patient B, knee flexion at the 1-month postoperative review