Clinical assessment, gait analysis and reliability of measurement with the G walk inertial sensor in subjects with ankle fracture 6 months after surgery.

Background: Ankle fractures can cause significant functional impairment in the short and long term. In recent years, gait analysis using inertial sensors has gained special relevance as a reliable measurement system.Objectives: In patients with bimalleolar ankle fracture, to identify the differences between the operated and healthy ankle in the spatial-temporal gait parameters and plantar pressures; likewise, to study their relationship with clinical parameters and functional scales. Finally, to assess the reliability of a single inertial sensor, placed on the lumbar spine, in our study population.Design: Cross-sectional study.Methods: Twenty-two subjects with bimalleolar ankle fractures were included in the study. An analysis of the spatial-temporal gait parameters and plantar pressures was carried out using an inertial system (G-WALK) and a pressure platform (P-WALK). Sociodemographic and clinical information was previously collected. Differences between the operated and healthy ankle were studied for each variable and their correlation with clinical measures and functional scales; then, a multiple linear regression analysis was performed with the variables that showed a significant correlation. Finally, the intra-session test-retest reliability of the G Walk was calculated using the intraclass correlation coefficient (ICC2,1) and the standard error of measurement (SEM).Results: Statistically significant differences were found for all spatial-temporal gait parameters and dynamic plantar pressures, except for double support (-1%; p=.267). Differences were also found for clinical measures, except for ADD strength (0.6%; p=.491). Effect sizes for gait variables ranged from 0.25 to 1.02 and for clinical variables ranged from 0.15 to 2.30. The highest degree of correlation of clinical measures and functional scales was obtained with speed, cadence, stride time, and propulsion. Intra-session test-retest reliability was high to excellent (0.840.98). Speed, stride length, and propulsion obtained the lowest SEM scores.Conclusions: In our study population, the analysis of spatial-temporal gait parameters and dynamic plantar pressures show an evident asymmetry between both limbs; likewise, they correlate moderately with ankle range of motion, hip abductor strength, and the AOFAS scale. The G-WALK inertial sensor can be considered a reliable gait measurement system in this population.