Comparison of Prosthetic Feet for People With Syme's Amputation (XF Symes Study)

Functional Assessment of High-profile Crossover Feet in People With Syme's Amputation

The purpose of this study is to compare the functional differences between two types of foot prostheses for people with ankle disarticulation (Syme's) amputations. The two feet being tested are low- and high-profile feet, with the difference being the latter has an extended keel and attaches to the posterior of the prosthetic socket, rather than the distal end. The hypothesis is that the high-profile foot (i.e., the crossover foot) will lead to functional and biomechanical improvements compared to low-profile feet.

Syme's prostheses are typically limited to low-profile prosthetic feet due to clearance restrictions below the prosthetic socket. As a result, the functional benefits provided by the long residual limb are mitigated by prosthetic design limitations. Recently, high-profile, posteriorly-attaching crossover feet have been modified for use with people who have Syme's amputation. Crossover feet theoretically improve motion and energy storage-and-return compared to traditional foot options for the Syme's level. Crossover feet also have the potential to broaden the range of high-impact activities that can be performed with a single prosthesis. However, to date there is no empirical evidence that compares functional differences when walking with high-profile crossover feet compared to low-profile feet for people with Syme's amputation. This mixed-method pilot research will use a randomized, controlled within-participants design. Investigators will assess gait biomechanics, self-reported health outcomes, and qualitative interviews to compare relative advantages and disadvantages of traditional low-profile Syme's feet and high-profile crossover feet. This proposed work will create a foundation for future research that examines the potential benefits of crossover feet in people with Syme's amputation. In addition, results from this research will be used clinically to inform prosthetic options for people with limited clearance for distally-attached prosthetic feet.

Inclusion Criteria:

• 18 years of age or older
• Have a unilateral Syme's amputation that occurred >1 year prior
• Owns a crossover foot modified for Syme's use
• Able to walk in the community without assistance
• Able to read and write in English

Exclusion Criteria:

• Have other amputations
• Have a health condition that would limit completion of the study protocol (e.g., skin breakdown, heart disease)