title: A novel in vivo impact device for evaluation of sudden limb loading response.
abstract: The lower limbs are subjected to large impact forces on a daily basis during gait, and ambulators rely on various mechanisms to protect the musculoskeletal system from these potentially damaging shocks. However, it is difficult to assess the efficacy of anatomical mechanisms and potential clinical interventions on impact forces because of limitations of the testing environment. The current paper describes a new in vivo measurement device (sudden loading evaluation device, or SLED) designed to address shortcomings of previous loading protocols. To establish the repeatability and validity of this testing device, reliability and human participant data were collected while the stiffnesses of simulated and prosthetic limbs were systematically varied. The peak impact forces delivered by the SLED ranged from 706±3 N to 2157±32 N during reliability testing and from 784±30 N to 938±18 N with the human participant. The relatively low standard deviations indicate good reliability within the impacts delivered by the SLED, while the magnitude of the loads experienced by the human participant (98-117% BW) were comparable to ground reaction forces during level walking. Thus, the SLED may be valuable as a research tool for investigations of lower-limb impact loading events.
authors.affiliation: Northwestern University Prosthetics-Orthotics Center Department of Physical Medicine and Rehabilitation, Feinberg School of Medicine, Northwestern University, 680 North Lake Shore Drive, Suite 1100, Chicago, IL 60611, USA; Department of Biomedical Engineering, McCormick School of Engineering and Applied Science, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208, USA; Jesse Brown VA Medical Center, Department of Veterans Affairs, 820 South Damen Avenue, Chicago, IL 60612, USA. Electronic address: e-boutwell@u.northwestern.edu.
authors.forename: Erin
authors.initials: E
authors.lastname: Boutwell
authors.affiliation: Northwestern University Prosthetics-Orthotics Center Department of Physical Medicine and Rehabilitation, Feinberg School of Medicine, Northwestern University, 680 North Lake Shore Drive, Suite 1100, Chicago, IL 60611, USA; Jesse Brown VA Medical Center, Department of Veterans Affairs, 820 South Damen Avenue, Chicago, IL 60612, USA. Electronic address: rstine@northwestern.edu.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Stine
authors.affiliation: Northwestern University Prosthetics-Orthotics Center Department of Physical Medicine and Rehabilitation, Feinberg School of Medicine, Northwestern University, 680 North Lake Shore Drive, Suite 1100, Chicago, IL 60611, USA; Department of Biomedical Engineering, McCormick School of Engineering and Applied Science, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208, USA; Jesse Brown VA Medical Center, Department of Veterans Affairs, 820 South Damen Avenue, Chicago, IL 60612, USA. Electronic address: sgard@northwestern.edu.
authors.forename: Steven
authors.initials: S
authors.lastname: Gard
mesh_terms: D000368:Aged; D000672:Amputation Stumps / Q000503:physiopathology; D001186:Artificial Limbs; D001696:Biomechanical Phenomena; D004548:Elasticity; D055615:Electrical Equipment and Supplies; D004867:Equipment Design; D006801:Humans; D007866:Leg / Q000502:physiology*; D008297:Male; D015203:Reproducibility of Results; D014741:Video Recording; D016138:Walking / Q000502:physiology
keywords: Impact loading; Lower limb; Mechanical testing; Reaction forces; Shock transmission