Assessing the DSR Ankle

Synchro Motion, LLC developed a novel MPC ankle. Because of its unique actuation scheme, the prosthesis can behave as: (1) a lockable conformal damper, (2) a variable set-point spring, and (3) an actively repositionable joint.

The investigators therefore refer to the device as the damping, stiffness, and repositioning (DSR) ankle. The DSR ankle is small, lightweight, quiet, and runs for multiple days on a single charge. No other commercially available prosthesis combines this set of features. It will be shown in preliminary work that the features of the DSR ankle can increase toe clearance in swing, reduce the time-to-foot-flat after heel strike, and improve weight bearing symmetry when standing on slopes for K3 Individuals with Lower Limb Amputation (ILLAs). These biomechanical functions have all been linked to improved safety and stability, which leads the investigators to hypothesize that the DSR ankle may provide benefits to K2 ILLAs as well.

The main purpose of this research is to determine the ways in which the DSR ankle may be adapted to provide benefits specifically to ILLAs who use their prosthesis at the K2 level. For purposes of the Phase I work, the development and assessment will be performed exclusively with K2 ILLAs in order to provide an opportunity to implement any necessary refinements to the DSR ankle to ensure optimal K2 performance. The remainder of the research is to quantify the effectiveness of the DSR ankle as compared to a predicate non-MPC ankle in improving performance for K2 ILLAs.

Inclusion criteria

• Adults aged 18-89 years
• Patients who have a unilateral transtibial amputation who are able to use a prosthesis and who currently use a passive, non-MPC prosthesis
• K2 level ambulators

Exclusion criteria

• Pregnant women
• Children (<18 years old)
• Prisoners or institutionalized individuals
• Individuals who have the inability to give informed consent
• Participants unable to walk for 2 minutes without an assistive device
• Participants with complicating health conditions that interfere with the study
• Inability to read and understand the English language. As this is a pilot study with a small sample size, it is prohibitive to translate Study documents to other languages as recruitment will be from a sample of convenience.