The purpose of this study is to analyze the biomechanical variables affecting the knee joint during cutting and running and to identify the activation patterns of active and passive forces by muscles. Twenty male participants performed running and cutting at a speed of 4.5±0.2 m/s. During running, they sprinted forward after the right foot contact on the force plate, whereas in the cutting, they shifted to the left within a range of 35° to 55° from the forward direction. Kinematic and kinetic variables were calculated, such as maximum knee joint angle, angular velocity, ground reaction force (GRF), moment, work, and shear force. The maximum forces of the knee flexor and extensor muscle groups were extracted through musculoskeletal modeling. During the passive phase of the cutting, the knee joint showed significantly greater abduction angles compared to running ( p<.05). GRF during the cutting were higher in the medial and vertical directions ( p<.05). Negative work and shear forces were greater during cutting than running ( p<.05). In the active phase, the joint moments for flexion, adduction, and internal rotation were significantly greater during cutting ( p<.05). Active muscle forces were higher in the biceps femoris long head, gracilis, semimembranosus, semitendinosus during cutting ( p<.05). The biceps femoris long head and gracilis showed greater active forces in the cutting, while the biceps femoris short head was more active during running ( p<.05). The cutting required certain knee flexors and hamstrings to exert greater forces to reduce knee joint loading during rotation, resulting in distinct differences in biomechanical variables and muscle recruitment patterns compared to running.