title: Effect of prosthetic alignment changes on socket reaction moment impulse during walking in transtibial amputees.
abstract: The alignment of a lower limb prosthesis affects the way load is transferred to the residual limb through the socket, and this load is critically important for the comfort and function of the prosthesis. Both magnitude and duration of the moment are important factors that may affect the residual limb health. Moment impulse is a well-accepted measurement that incorporates both factors via moment-time integrals. The aim of this study was to investigate the effect of alignment changes on the socket reaction moment impulse in transtibial prostheses. Ten amputees with transtibial prostheses participated in this study. The socket reaction moment impulse was measured at a self-selected walking speed using a Smart Pyramid in 25 alignment conditions, including a nominal alignment (clinically aligned by a prosthetist), as well as angle malalignments of 2°, 4° and 6° (abduction, adduction, extension and flexion) and translation malalignments of 5 mm, 10 mm and 15 mm (lateral, medial, anterior and posterior). The socket reaction moment impulse of the nominal alignment was compared for each condition. The relationship between the alignment and the socket reaction moment impulse was clearly observed in the coronal angle, coronal translation and sagittal translation alignment changes. However, this relationship was not evident in the sagittal angle alignment changes. The results of this study suggested that the socket reaction moment impulse could potentially serve as a valuable parameter to assist the alignment tuning process for transtibial prostheses. Further study is needed to investigate the influence of the socket reaction moment impulse on the residual limb health.
authors.affiliation: Orthocare Innovations, Mountlake Terrace, WA 98043-2180, USA. Electronic address: tkobayashi@orthocareinnovations.com.
authors.forename: Toshiki
authors.initials: T
authors.lastname: Kobayashi
authors.affiliation: Orthocare Innovations, Mountlake Terrace, WA 98043-2180, USA.
authors.forename: Michael S
authors.initials: MS
authors.lastname: Orendurff
authors.affiliation: Department of Engineering and Computer Science, Seattle Pacific University, WA, USA.
authors.forename: Adam K
authors.initials: AK
authors.lastname: Arabian
authors.affiliation: Orthocare Innovations, Mountlake Terrace, WA 98043-2180, USA.
authors.forename: Teri G
authors.initials: TG
authors.lastname: Rosenbaum-Chou
authors.affiliation: Orthocare Innovations, Mountlake Terrace, WA 98043-2180, USA.
authors.forename: David A
authors.initials: DA
authors.lastname: Boone
mesh_terms: D000328:Adult; D000368:Aged; D000674:Amputees; D001186:Artificial Limbs; D001696:Biomechanical Phenomena; D005121:Extremities; D005260:Female; D005684:Gait; D006801:Humans; D008297:Male; D008875:Middle Aged; D010003:Osteoarthritis / Q000503:physiopathology; D011474:Prosthesis Design; D016059:Range of Motion, Articular; D013977:Tibia / Q000601:surgery; D016138:Walking
keywords: Amputation; Direct measurement; Gait; Knee adduction moment impulse; Osteoarthritis