Validity of the activPAL and ActiGraph for measuring sitting time and steps in hospitalised orthopaedic patients with altered weight bearing
Asher Kirk1,2, Lara Kimmel1,2, Kate Behm1, Casey Peiris3, Christina Ekegren1,2 1Alfred Health, Melbourne, Victoria, Australia2Monash University, Melbourne, Victoria, Australia3Latrobe University, Melbourne, Victoria, Australia
Abstract
Purpose: To determine the criterion validity of the activPAL and ActiGraph for measuring steps and sitting/sedentary time, compared to observation, in people hospitalised following orthopaedic lower limb injury who were weight bearing (WB) (i.e. walking) or non-weight bearing (NWB) (i.e. hopping).
Materials and methods: Participants wore an activPAL and ActiGraph on the hip/thigh/unaffected (UA)/affected ankle (AA) while completing bouts of walking and sitting. Lins Concordance Correlation Coefficient, Bland-Altman methods and ratio of agreement were used to compare device-measured to observed (videoed) step count, sitting/sedentary time.
Results: In 42 participants, the ActiGraph demonstrated excellent concordance with the observed step count when worn on the ankle (LCC 0.91-0.92) compared to the hip (LCC 0.56) in participants that were WB. The ActiGraph AA achieved the highest concordance (LCC 0.71) with observed steps in participants NWB. The activPAL had poor concordance with observed steps, particularly at slow gait speeds, in participants that were WB (LCC 0.38-0.46), however was less influenced by gait speed and had good concordance in NWB participants (LCC 0.52-0.69). The activPAL (LCC 0.79-0.88) and ActiGraph UA (LCC 0.94) showed excellent concordance with observed sitting and sedentary time, respectively.
Conclusions: The ActiGraph worn at the ankle provided the most valid measure of steps in people who are WB and NWB following orthopaedic injury, while the activPAL was best for measuring sitting time.
Biography
Asher Kirk is a senior orthopaedic trauma physiotherapist from the Alfred Hospital, Melbourne and a PhD candidate at Monash University. Having vast experience in Australia and United Kingdom, Asher has a special interest in major orthopaedic and spinal trauma. Asher’s PhD is investigating activity levels during and after hospitalisation in people with orthopaedic trauma, and hopes this research will continue to improving the outcomes in people following orthopaedic trauma.