Activity monitor accuracy in persons using canes

Abstract

Abstract-TheStepWatch activity monitor has not been validated on multiple indoor and outdoor surfaces in a population using ambulation aids. The aims of this technical report are to report on strategies to configure the StepWatch activity monitor on subjects using a cane and to report the accuracy of both leg-mounted and cane-mounted StepWatch devices on people ambulating over different surfaces while using a cane. Sixteen subjects aged 67 to 85 yr (mean 75.6) who regularly use a cane for ambulation participated. StepWatch calibration was performed by adjusting sensitivity and cadence. Following calibration optimization, accuracy was tested on both the legmounted and cane-mounted devices on different surfaces, including linoleum, sidewalk, grass, ramp, and stairs. The legmounted device had an accuracy of 93.4% across all surfaces, while the cane-mounted device had an aggregate accuracy of 84.7% across all surfaces. Accuracy of the StepWatch on the stairs was significantly less accurate (p < 0.001) when comparing surfaces using repeated measures analysis of variance. When monitoring community mobility, placement of a StepWatch on a person and his/her ambulation aid can accurately document both activity and device use.

Implementation of Wearable Sensing Technology for Movement: Pushing Forward into the Routine Physical Rehabilitation Care Field

“…As many individuals who seek physical rehabilitation walk at slower speeds, this poses a major barrier for accurate, objective monitoring. In contrast to the consumer-grade devices, commercially-available, research-grade sensors such as the Step Activity Monitor (Modus Inc., Edmonds, WA, USA) have demonstrated strong reliability and accuracy across varied levels of abilities, including differing medical diagnosis, variable gait speeds, and use of assistive devices [ 41 , 49 , 50 , 51 , 52 , 53 , 54 ] with limited data across differing environmental conditions [ 40 , 54 , 55 , 56 ]. Though this research grade device is accurate and reliable in individuals with physical impairments, the device may lack key features that would be essential for widespread clinical adoption (see Section 4 below).…”

Effect of body weight support on predicted locomotive physical activity

“…To clarify the effects of BWS with assistive devices on locomotive physical activities, subjects with or without assistive devices should walk at the same speed. Other reports also examined the accuracy of pedometers and accelerometers in older adults, including cane users; however, these reports did not focus solely on the effects of BWS with assistive devices 14 , 15 , 16 ) .…”

“…Recently, locomotive physical activities have been objectively assessed using triaxial accelerometers 5 , 6 , 7 , 8 , 9 , 10 ) . Triaxial accelerometers have shown reliability and validity in evaluating locomotive physical activities in adults 11 , 12 , 13 ) ; however, several studies have reported inconsistent results 14 , 15 , 16 , 17 , 18 , 19 ) . Furthermore, only a few studies have examined the effects of BWS with assistive devices on predicted locomotive physical activities using a triaxial accelerometer 19 ) .…”

Comparison of Self-Reported vs Objective Measures of Long-Term Community Ambulation in Lower Limb Prosthesis Users

“…The StepWatch 3 Activity Monitor is a medical device and validated in a lower limb amputee populations 11 and populations that include slow and/or abnormal walkers. 3 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 It measures not only daily steps but also peak performance index, walking distance, cadence, and cadence variability, as well as giving a functional-level assessment based on a proprietary algorithm that attempts to combine all of the metrics into one number to approximate the K-level (given as an number from 1 to 4). The functional-level algorithm was previously demonstrated to have good ( R 2 =0.78) 40 to excellent ( r =0.96) 2 agreement with clinically determined K-levels in cohorts of transtibial amputees.…”