Early post-operative walking bouts are associated with improved gait speed and symmetry at 90 days

Introduction: There is a paucity of literature on optimal patterns of daily walking following joint arthroplasty, which are now evaluated with consumer technologies like smartphones, and can enhance our understanding of post-operative mobility. When smartphone-recorded, daily walking patterns are captured, qualities of gait-recovery such as gait speed or symmetry can be analyzed in real-world environments.

Research question: Are the daily distribution of walking bouts in the early post-operative period associated with 90-day gait quality measures following hip and knee arthroplasty?

Methods: Gait data was collected passively using a smartphone-based care management platform in patients undergoing hip and knee arthroplasty. As recorded via subjects' free-living smartphone-collected gait bouts, data were investigated as a function of the walking session length and were used to create a ratio to the total time logging bouts, representing the fraction of walking performed during a single session per day (aggregation score). Quantile regression was performed to evaluate the association between early walking session lengths or aggregation score at 30 days post-operatively and the gait-sampled speed and asymmetry of walking at 90 days.

Results: In total, 2255 patients provided evaluable data. The walking session length at 30 days was positively associated with 90-day mean gait speed across procedure types where quantile regression coefficients ranged from 0.11 to 0.17. In contrast, aggregation score was negatively associated with gait speed at 90 days, with coefficients ranging from -0.18 to -0.12.

Significance: The duration and frequency of walking bouts was associated with recovery of gait speed and symmetry following lower limb arthroplasty. The findings may help clinicians design walking protocols that are associated with improved gait metrics at 3 months.