To maximize the benefits of the newly developed powered prosthetic legs, amputees must rely on tuning experts (TE) from manufacturers to tune these devices based on their specific physical conditions. Because TEs are hard to train, it is difficult to access the TEs and the cost of customization is high. If the knowledge used by the TEs could be extracted, it is possible to reduce the tuning cost by automating the tuning procedure or developing efficient TE training programs. In this paper, we preliminarily identified kinematic features that are sensitive to the control parameter change of the powered prosthetic leg. Using data collected from three transtibial amputee subjects with four levels of push-off power, we tested whether a change of push-off power could generate a significant difference on 13 preselected kinematic features during level ground walking at self-selected walking speed. Six features across three joints on the prosthesis side were demonstrated to be sensitive to the change of push-off power.