Functional outcomes and user preferences of individuals with transfemoral amputations using two types of knee joints in under-resourced settings

A systematic review on cross-cultural validations and psychometric solidity of the orthotics and prosthetics user survey

Research is essential to reflect patients' satisfaction with their devices in the field of Prosthetics and Orthotics, record their performance and health-related quality of life. This requires culturally adapted questionnaires for each country. Periodic assessment of validity and test fit are essential elements for the long-term utility and effectiveness of psychometric tests. This article reviews the psychometric properties of the Orthotics and Prosthetics Users Survey (OPUS). The purpose, in addition to its adaptation to the Spanish-speaking population, involves a review/update of content, statistical analyses, and validity studies, until a larger number of studies are conducted. Study design: a Systematic review. A systematic literature search was carried out in specialized search engines: Alcorze (University of Zaragoza), MEDLINE (PubMed), and EMBASE of original articles published since 2000. Eleven items belonging to the OPUS were obtained, according to the language of the country where they were validated, and promising psychometric properties were confirmed (reflecting reliability values between 0.62 and 0.95; Cronbach's α scores between 0.73 and 0.98) with sample sizes between 10 and 321. The study concluded by stating that the OPUS was validated in different languages, reporting good psychometric robustness so far. Further deployment, refinement, and validation of this survey by country is warranted in view of its promising use.

Gait Performance of Friction-Based Prosthetic Knee Joint Swing-Phase Controllers in Under-Resourced Settings

Gait quality can influence walking ability and mobility outcomes making it an important part of prosthetic rehabilitation. Prosthetic knee joint designs can influence gait quality, and limited data exists to guide component selection in under-resourced settings. This study compared spatiotemporal and kinematic gait parameters for two common types of friction-based swing-phase controlled prosthetic knee joints. Two-dimensional optical gait analysis was conducted as part of a cross-over study design involving 17 individuals with unilateral transfemoral amputations. Two prosthetic knee joints were compared. One utilized constant-friction (CF) and the other a variable cadence controller (VCC) for swing-phase control. Gait was analyzed at normal and fast walking speeds. Primary gait parameters included swing-phase time, step length, and knee flexion. Swing-phase time and peak knee flexion angles, as well as their related symmetry indices, were lower for the VCC compared to the CF (p < 0.01), by 11.1 to 94.1%. The VCC resulted in faster walking speeds by approximately 15% compared to the CF (p = 0.002). Friction-based swing-phase knee control mechanisms can facilitate an appropriate and cost-effective prosthetic knee joint solution in under-resourced settings. The findings suggest that friction-based mechanism can be designed to improve gait quality, and in turn overall walking performance.