Objective:To explore the effects of mechanical factors on the morphology of the growth plate and proximal femur development, in order to provide a mechanical basis for the mechanism of Cam lesions in femoral acetabular impingement (FAI).Methods:Using CT scan data of hip joint from adolescents, we constructed three-dimensional finite element models of normal and extended proximal femoral epiphyseal growth plates. Dynamic mechanics and position data from daily activities (walk, stand on one and two feet, go upstairs and downstairs, sit and stand up, squat and stand up) and basketball layup drills were collected from five healthy volunteers using the Vicon system. The mean values of femoral head mechanical loads and positions at peak values, movement onset, and termination were selected for finite element analysis to observe the distribution of equivalent stress, normal stress, and shear stress on the two growth plate models under different activity modes.Results:Successful construction of three-dimensional finite element models for normal and extended proximal femoral epiphyseal growth plates was achieved. Mechanical load values and spatial positions of the femoral head during daily activities and layup movements were obtained. In daily activities, peak equivalent stress values for normal and extended growth plates ranged from 1.6 to 11.0 MPa; compressive stress ranged from 1.7 to 12.0 MPa; tensile stress ranged from 0.5 to 10.0 MPa; and shear force ranged from 0.4 to 7.1 MPa. The compressive stress during walking, standing on one or both feet, going up and down stairs, sitting and standing, and squatting was concentrated in the central and lateral areas; tensile stress was concentrated in the central and medial areas; shear force was concentrated in the medial area and the anterior and posterior edges of the growth plate. During a layup, the compressive stress in the center, outer upper side, and medial edge of the growth plate of the normal model was notably concentrated, with peaks fluctuating between 5.5-19.0 MPa, 5.7-11.0 MPa, and 5.4-7.3 MPa respectively; tensile stress and shear force were concentrated at the inner and outer edges as well as in the central area, with peaks fluctuating between 3.0-24.0 MPa and 3.0-26.0 MPa respectively, these values were significantly different from those observed during daily activities. For the elongated growth plate, compressive stress was concentrated at the central and lateral edges with peaks fluctuating between 17.0-41.0 MPa and 17.0-38.0 MPa respectively; simulated shear stress and tensile stress showed significant concentration at peaks fluctuating between 4.9-34.0 MPa, also significantly different from those observed during daily activities.Conclusion:The difference in mechanical distribution between daily activities, basketball layup training, as well as between normal and extended growth plates may be the mechanical initiating factor in the development of extended growth plates and the formation of Cam lesions, it may be the mechanical initiating factor for the development of extended growth plates and the collision of Cam lesions in FAI.