Accelerometer-determined Step-count, Peak 1-minute Cadence, And Walking Intensity In Persons With And Without Acetabular Dysplasia.

Abstract

PURPOSE: Acetabular dysplasia (AD) is a condition of the hip joint that is characterized by shallow acetabular coverage of the femoral head resulting in pain, decreased function, and/or hip osteoarthritis (OA). The slowing of walking speed has been identified as a risk factor for activity limitations and the development of hip OA. The identification of innovative measures of patterns of walking behavior and intensity may provide insight into disease progression and joint health in persons with AD. We compared mean daily steps, peak 1-minute cadence, and mean time spent in varying walking behavior and intensities between persons with and without AD. METHODS: We enrolled 12 persons with AD (11 females) and 14 healthy controls (9 females), and all wore an accelerometer (ActiGraph GT3X+) around the waist (uninvolved limb for AD; non-dominant limb for controls) during waking hours over 7 days. Valid wear time (≥ 4 days of ≥480 min/day) was confirmed before data analyses. We used one-way ANCOVA controlling for wear time when examining group differences in 1) mean daily steps, 2) peak 1-minute cadence (steps/min), and 3) mean time spent in slow (60-79 steps/min), medium (80-99 steps/min), and moderate-to-vigorous physical activity (MVPA; ≥100 steps/min) walking intensities. RESULTS: The groups did not differ in age or sex distributions (p > 0.05), but did differ in BMI (controls = 26.3; AD group = 22.9; p = 0.018). Persons with AD took fewer mean daily steps (controls = 8,427.9 steps/day; AD group = 4,550.9 steps/day; η2 = .24; p = 0.012) and had lower peak 1-minute cadence (controls = 143.1 steps/min; AD group = 104.5 steps/min; η2 = .48; p < 0.001) than controls. Persons with AD spent less mean time in slow (controls = 12.1 min/day; AD group = 4.7 min/day; η2 = .35; p = 0.002), medium (controls = 10.6 min/day; AD group = 2.6 min/day; η2 = .41; p < 0.001), and MVPA (controls = 20.1 min/day; AD group = 2.5 min/day; η2 = .33;p = 0.003) walking intensity than controls. CONCLUSIONS: Persons with AD took fewer mean daily steps, had lower peak 1-minute walking cadence, and spent less mean time in all walking cadence categories when compared with healthy controls. Future studies should examine modifiable factors associated with walking behavior in persons with AD, as well as the longitudinal association between walking behavior and future hip joint health.