title: Stance time variability during stair stepping before and after total knee arthroplasty: A pilot study.
abstract: The main objectives of this pilot study were to: (1) investigate stance time variability (STV) during stair stepping in older adults with osteoarthritis (OA) before and after total knee arthroplasty (TKA), and compare to an age- and sex-matched group of healthy controls with native knees and (2) evaluate the relationship between quadriceps strength and STV during stair stepping before and after TKA. A prospective, observational, pilot study was carried out on 13 individuals (15% male, mean age 62.71±6.84years) before and after TKA using an instrumented stairway, patient-reported outcomes, timed stair stepping test, and quadriceps strength measures. At 6-months post-operatively, STV during stair descent was significantly greater in the TKA-GROUP compared to the CONTROL-GROUP, but was not significantly different at 12-months compared to controls. There were no significant differences in STV for stair ascent between the pre- and post-operative visits, or compared to controls. There was a trend toward significance for the relationship between quadriceps strength and STV during stair ascent (P=0.059) and descent (P=0.073). Variability during stair stepping may provide an important, short-term rehabilitation target for individuals following TKA and may represent another parameter to predict declines in functional mobility.
authors.affiliation: Department of Bioengineering, University of Utah, Salt Lake City, UT, USA; Department of Physical Therapy, University of Utah, Salt Lake City, UT, USA. Electronic address: j.smith@utah.edu.
authors.forename: Jessica W
authors.initials: JW
authors.lastname: Smith
authors.affiliation: Department of Physical Therapy, University of Utah, Salt Lake City, UT, USA; Department of Exercise and Sport Science, University of Utah, Salt Lake City, UT, USA.
authors.forename: Robin L
authors.initials: RL
authors.lastname: Marcus
authors.affiliation: Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, USA.
authors.forename: Brian L
authors.initials: BL
authors.lastname: Tracy
authors.affiliation: Department of Physical Therapy, University of Utah, Salt Lake City, UT, USA; Department of Orthopedics, University of Utah, Salt Lake City, UT, USA.
authors.forename: K Bo
authors.initials: KB
authors.lastname: Foreman
authors.affiliation: Department of Physical Therapy, University of Utah, Salt Lake City, UT, USA; Department of Orthopedics, University of Utah, Salt Lake City, UT, USA.
authors.forename: Jesse C
authors.initials: JC
authors.lastname: Christensen
authors.affiliation: Department of Bioengineering, University of Utah, Salt Lake City, UT, USA; Department of Physical Therapy, University of Utah, Salt Lake City, UT, USA; Department of Orthopedics, University of Utah, Salt Lake City, UT, USA; Department of Exercise and Sport Science, University of Utah, Salt Lake City, UT, USA.
authors.forename: Paul C
authors.initials: PC
authors.lastname: LaStayo
mesh_terms: D000328:Adult; D000368:Aged; D019645:Arthroplasty, Replacement, Knee; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D051346:Mobility Limitation; D053580:Muscle Strength / Q000502:physiology*; D020370:Osteoarthritis, Knee / Q000503:physiopathology* / Q000601:surgery*; D010865:Pilot Projects; D011183:Postoperative Complications / Q000503:physiopathology; D011446:Prospective Studies; D052097:Quadriceps Muscle / Q000503:physiopathology; D016059:Range of Motion, Articular / Q000502:physiology; D013997:Time Factors
keywords: Motor processes; Rehabilitation; Sensory perception