Caesar Foot Take-Home Validation Testing

Inclusion Criteria: * Have transtibial limb absence of one or both limbs * Express interest in running, but do not currently have a running blade (as determined by self-report) * Are at least 18 years of age * Are at least six months post amputation * Are classified as K3 or K4 ambulator status as determined by a certified prosthetist * Have an AMP score of at least 37 * Are capable of running safely as determined by a certified prosthetist's clinical judgement * Have a well-fitting socket as determined by a certified prosthetist * Have adequate clearance between distal end of the residual limb and ground for the Caesar foot * Meets the foot size and weight class of one of the available Caesar prototypes Exclusion Criteria: * Present or sustained injuries to residual limb or contralateral leg affecting functional ability * Non-English speaking participants will be excluded from this study due to limited access to interpreter services. These services would be needed for several visits, including training to learn how to use the device safely, along with requested verbal feedback from the participant to evaluate the design and usability of the system. * Using a prosthetic foot that an individual is unfamiliar with for higher activity tasks may increase the risk of falling. Therefore, pregnant women should not participate in the study and will be screened by self-disclosure. Individuals can be excluded at the discretion of the investigator for other unforeseen disqualifying criteria (such as specific cognitive issues, etc.).