The gait of an individual with a transtibial amputation can be influenced by the suspension system employed in their prosthesis. Suspension is a fundamental element for ensuring the stability and comfort of the prosthesis, as well as providing optimal control for those with lower-limb amputations. Gait analysis is a highly effective tool for comparing different prosthetic suspension systems. This study compares two common suspension systems for transtibial prostheses: Pin-lock and Vacuum, analyzing the biomechanical gait of a patient with a unilateral transtibial amputation. The evaluation was conducted in a gait analysis laboratory, where kinematic, kinetic, and muscle activation parameters were assessed using electromyography sensors on both lower extremities. Kinematic results reveal asymmetric gait, with the prosthetic limb showing negative pelvic displacement and increased spinal motion. Both systems deviate from normal patterns, particularly in knee and hip movement. Pin-lock shows higher muscle activation overall, except in the right ischium where Vacuum is higher; calf and tibia activation on the intact limb is also greater with Pin-lock, possibly reflecting differences in stability or gait dynamics. These results underscore the critical importance of closely examining the performance of transtibial prosthetic suspension systems and considering their potential effects on gait.