Development and validation of a physical activity monitor for use on a wheelchair

Abstract

Study design: Keeping physically active is important for people who mobilize using a wheelchair. However, current tools to measure physical activity in the wheelchair are either not validated or limited in their application. The purpose of this study was to develop and validate a monitoring system to measure wheelchair movement. Methods: The system developed consisted of a tri-axial accelerometer placed on the wheel of a wheelchair and an analysis algorithm to interpret the acceleration signals. The two accelerometer outputs in the plane of the wheel were used to calculate the angle of the wheel. From this, outcome measures of wheel revolutions, absolute angle and duration of movement were derived and the direction of movement (forwards or backwards) could be distinguished. Concurrent validity was assessed in comparison with video analysis in 14 people with spinal cord injury using their wheelchair on an indoor track and outdoor wheelchair skills course. Validity was assessed using intraclass correlation coefficients (ICC(2,1)) and Bland-Altman plots.Results: The monitoring system demonstrated excellent validity for wheel revolutions, absolute angle and duration of movement (ICC(2,1)40.999, 0.999, 0.981, respectively) in both manual and powered wheelchairs, when the wheelchair was propelled forwards and backwards, and for movements of various durations. Conclusion: This study has found this monitoring system to be an accurate and objective tool for measuring detailed information on wheelchair movement and manoeuvring regardless of the propulsion technique, direction and speed.

Preliminary study for the assessment of physical activity using a triaxial accelerometer with a gyro sensor on the upper limbs of subjects with paraplegia driving a wheelchair on a treadmill

“…4,8 A series of reports based on studies of activity evaluation devices in wheelchair-using persons after SCI has been published in recent years. [9][10][11][12][13][14][15] Coulter et al 9 and Sonenblum et al 10,11 conducted several studies using multiaxial or triaxial accelerometers mounted on the wheels of wheelchairs. However, if the work involves mainly tasks using active muscles in the upper limbs, conducting an evaluation of physical activity using devices reflecting the movements of the upper limbs would be both legitimate and rational.…”

Development and evaluation of a gyroscope-based wheel rotation monitor for manual wheelchair users

“…Research has shown that wheel rotation monitors can be used to assess mobility characteristics, activity levels, and wheelchair use of MWUs in laboratory, community and nursing home settings. [1][2][3][4] However, there are only a limited number of monitoring tools available for manual wheelchair users (MWUs). [2][3][4][5][6] This is especially striking as the general population can choose from a wide array of activity monitors to track their activities in the community in terms of steps, intensity of PA, duration of PA, and energy expenditure.…”

“…[1][2][3][4] However, there are only a limited number of monitoring tools available for manual wheelchair users (MWUs). [2][3][4][5][6] This is especially striking as the general population can choose from a wide array of activity monitors to track their activities in the community in terms of steps, intensity of PA, duration of PA, and energy expenditure. [7][8][9][10][11] The availability of activity monitors for MWUs can help researchers and clinicians in the fields of rehabilitation science, kinesiology, and health and physical activity to study mobility characteristics and evaluate mobility related interventions in this population.…”

“…12,13 The existing measurement tools for MWUs have varying sensitivity and accuracy in estimating speeds and distances traveled by wheelchair users. These tools either use a pendulum and reed switch-based method 2 or accelerometer-based method 3,4,6 to sense wheel pendulum and reed switch-based device on a double drum that simulates wheelchair use. The percentage errors for the device when estimating the speeds varying from 0.8 to 1.8 m/s were found to be 1 and 5%, respectively.…”

“…The percentage errors for the device when estimating the speeds varying from 0.8 to 1.8 m/s were found to be 1 and 5%, respectively. Coulter et al 4 investigated a wheelmounted tri-axial accelerometer and found the device was highly accurate in estimating wheel revolutions, absolute angle and duration of movement (ICC (2,1) > 0.999, 0.999, 0.981, respectively) when 14 wheelchair users were asked to propel their wheelchairs forward and backward along a course. Sonenblum et al 3 evaluated a wheel-mounted tri-axial accelerometer in detecting wheelchair movements and estimating distances traveled.…”