title: Understanding dynamic stability from pelvis accelerometer data and the relationship to balance and mobility in transtibial amputees.
abstract: This study investigated whether pelvis acceleration-derived parameters can differentiate between dynamic stability states for transtibial amputees during level (LG) and uneven ground (UG) walking. Correlations between these parameters and clinical balance and mobility measures were also investigated. A convenience sample of eleven individuals with unilateral transtibial amputation walked on LG and simulated UG while pelvis acceleration data were collected at 100Hz. Descriptive statistics, Fast Fourier Transform, ratio of even to odd harmonics, and maximum Lyapunov exponent measures were derived from acceleration data. Of the 26 pelvis acceleration measures, seven had a significant difference (p≤0.05) between LG and UG walking conditions. Seven distinct, stability-relevant measures appeared in at least one of the six regression models that correlated accelerometer-derived measures to Berg Balance Scale (BBS), Community Balance and Mobility Scale (CBMS), and Prosthesis Evaluation Questionnaire (PEQ) scores, explaining up to 100% of the variability in these measures. Of these seven measures, medial-lateral acceleration range was the most frequent model variable, appearing in four models. Anterior-posterior acceleration standard deviation and stride time appeared in three models. Pelvis acceleration-derived parameters were able to differentiate between LG and UG walking for transtibial amputees. UG walking provided the most relevant data for balance and mobility assessment. These results could translate to point of patient contact assessments using a wearable system such as a smartbelt or accelerometer-equipped smartphone.
authors: Department of Systems Design Engineering, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, Canada N2L 3G1. Electronic address: j2irwin@uwaterloo.ca.
authors: Jennifer
authors: J
authors: Howcroft
authors: Ottawa Hospital Research Institute, Centre for Rehabilitation, Research and Development, 505 Smyth Road, Ottawa, Ontario, Canada K1H 8M2; University of Ottawa, Faculty of Medicine, 451 Smyth Road, Ottawa, Ontario, Canada K1H 8M5. Electronic address: elemaire@ottawahospital.on.ca.
authors: Edward D
authors: ED
authors: Lemaire
authors: Department of Systems Design Engineering, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, Canada N2L 3G1. Electronic address: jkofman@uwaterloo.ca.
authors: Jonathan
authors: J
authors: Kofman
authors: Ottawa Hospital Research Institute, Centre for Rehabilitation, Research and Development, 505 Smyth Road, Ottawa, Ontario, Canada K1H 8M2. Electronic address: kendellcynthia@gmail.com.
authors: Cynthia
authors: C
authors: Kendell
mesh_terms: D000054:Acceleration; D061725:Accelerometry; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000674:Amputees / Q000534:rehabilitation*; D001186:Artificial Limbs; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010388:Pelvis / Q000503:physiopathology*; D004856:Postural Balance / Q000502:physiology*; D013977:Tibia / Q000601:surgery*; D016138:Walking / Q000502:physiology*
keywords: Acceleration; Dynamic stability; Gait; Transtibial amputee; Wearable sensor