Objective To investigate the effect of trunk control on the biomechanical characteristics of lower-extremity movements during Asian squats (AS) and Western squats (WS) in young adults to provide empirical support for the application and promotion of deep squat training. Methods Twenty-four healthy young male collegiate students performed AS and WS with and without bar control, and their lower-extremity kinematic and kinetic characteristics were collected using an infrared light-point motion capture system and a three-dimensional (3D) dynamometer. The 3D angles of the lower extremities were obtained using Cortex-642.6.2 software, based on the calculation of Euler angles, and the 3D moments were obtained by applying the inverse dynamics method. The effects of trunk control and deep squatting posture on the lower-extremity kinematic characteristics were examined using a two-factor analysis of variance with a 2 × 2 repeated design. Results There was no significant interaction between trunk control and the deep squatting posture for either kinematic or kinetic parameters (P > 0.05). The WS group had a large knee flexion angle, peak patellofemoral contact force, and ratio of peak hip and knee extension moments, and small ankle dorsiflexion and hip flexion angles (P<0.05). The deep squat with a bar had a large ankle dorsiflexion angle, peak patellofemoral contact force, and hip flexion angle as well as a small knee flexion angle and ratio of peak hip and knee extension moments (P<0.05). Conclusions WS is helpful for training hip extension muscle groups, whereas AS is helpful for training knee extension muscle strength. The peak patellofemoral joint contact force of the WS is significantly greater than that of the AS; therefore, it is recommended that patients with patellofemoral joint pain use the AS. A squat with a bar can compensate for the body’s balance; thus, people with limited ankle dorsiflexion range of motion or anterior tibial muscle weakness may consider trunk control training, such as a deep squat with a bar. This may help improve lower-extremity stability during squats.