In a recent paper from our group, we demonstrated that Front and Back squats performed on a Smith machine do not seem to elicit differences in muscle or joint forces. In this study we used a comprehensive musculoskletal model to determine muscle forces. This model was sensitive to increments in load, showing larger engagement of Gluteus medius and minimus when participants were lifting 80% of their 1-RM. It seems that, even though upper body position was different between Front and Back squats, individual choices related to the position of the pelvis (i.e. pelvic tilt) affect the engagement of hip and knee muscles.