There are different questions that our study wants to address: Is gait symmetry indeed a valid measure of prosthetic performance (e.i. is it the most energy efficient way to walk)? How does the gait pattern change when the prosthesis user walks on different surfaces, becomes tired or tries to compensate for a less-than-optimal prosthesis fit? How can gait symmetry be objectively assessed without using an expensive motion analysis laboratory? We hope that our findings will provide practically useful information that can help improve prosthetic fittings in the field.