title: Immediate Effects of a Brace on Gait Biomechanics for Predominant Lateral Knee Osteoarthritis and Valgus Malalignment After Anterior Cruciate Ligament Reconstruction.
abstract: BACKGROUND
  Lateral knee osteoarthritis is notably common after anterior cruciate ligament reconstruction (ACLR). While valgus bracing has been investigated as an intervention for medial knee osteoarthritis (OA), little is known about the effectiveness of varus bracing for lateral knee OA after ACLR.
  
  
  OBJECTIVE
  To determine the immediate effects of a varus unloader knee brace on gait biomechanics in people with lateral knee OA and valgus malalignment after ACLR.
  
  
  METHODS
  Controlled laboratory study.
  
  
  METHODS
  Nineteen participants who had undergone primary ACLR 5 to 20 years previously and had symptomatic and radiographic lateral knee OA as well as valgus malalignment were included. Three-dimensional gait analyses were conducted during walking under 3 test conditions: (1) no brace, (2) unadjusted brace (sagittal plane support with neutral frontal plane adjustment), and (3) adjusted brace (sagittal plane support with varus adjustment). Knee, pelvis, hip, and ankle kinematics and moments data were statistically analyzed using repeated-measures analysis of variance (α = 0.05).
  
  
  RESULTS
  Compared with walking with no brace, the adjusted brace significantly increased peak knee flexion angle (mean difference [95% CI]: 3.2° [1.3° to 5.0°]) and adduction angle (1.7° [0.8° to 2.6°]) and reduced peak internal rotation angle (-3.0° [-4.0° to -2.0°]). Significant increases in peak knee flexion moment (0.14 N·m/kg [0.06 to 0.20 N·m/kg]), adduction moment (0.10 N·m/kg [0.07 to 0.14 N·m/kg]), and external rotation moment (0.01 N·m/kg [0.00 to 0.02 N·m/kg]) were observed with the adjusted brace. The adjusted brace also reduced peak hip adduction angle (-1.29° [-2.12 to -0.47]) and increased peak hip adduction (0.17 N·m/kg [0.04 to 0.31 N·m/kg]) and external rotation moments (0.09 N·m/kg [0.03 to 0.14 N·m/kg]). There were no significant differences between the adjusted and unadjusted brace conditions, except for knee internal rotation angle, where the adjusted brace produced significantly greater reductions relative to the unadjusted brace (-1.46° [-1.98 to -0.95]).
  
  
  CONCLUSIONS
  Irrespective of frontal plane adjustment, the varus unloader brace produced immediate modulations in sagittal, frontal, and transverse plane joint angles and moments in younger individuals with lateral knee OA and valgus malalignment after ACLR.
  
  
  CONCLUSIONS
  The varus unloader brace may have the potential to mitigate abnormal knee joint mechanics associated with the development and progression of lateral knee OA after ACLR.
authors: Department of Mechanical Engineering, The University of Melbourne, Parkville, Victoria, Australia Department of Physiotherapy, The University of Melbourne, Parkville, Victoria, Australia.
authors: Harvi F
authors: HF
authors: Hart
authors: School of Health and Rehabilitation Sciences, The University of Queensland, Brisbane, Queensland, Australia.
authors: Natalie J
authors: NJ
authors: Collins
authors: Department of Mechanical Engineering, The University of Melbourne, Parkville, Victoria, Australia.
authors: David C
authors: DC
authors: Ackland
authors: Department of Physiotherapy, The University of Melbourne, Parkville, Victoria, Australia Physiotherapy Department, St Vincent's Hospital, Melbourne, Victoria, Australia.
authors: Sallie M
authors: SM
authors: Cowan
authors: Department of Physical Therapy, The University of British Columbia, British Columbia, Canada.
authors: Michael A
authors: MA
authors: Hunt
authors: Department of Mechanical Engineering, The University of Melbourne, Parkville, Victoria, Australia School of Health and Rehabilitation Sciences, The University of Queensland, Brisbane, Queensland, Australia School of Allied Health, La Trobe University, Bundoora, Victoria, Australia k.crossley@latrobe.edu.au.
authors: Kay M
authors: KM
authors: Crossley
mesh_terms: D000328:Adult; D059549:Anterior Cruciate Ligament Reconstruction / Q000009:adverse effects*; D001696:Biomechanical Phenomena / Q000502:physiology; D017760:Bone Malalignment / Q000503:physiopathology / Q000628:therapy*; D001915:Braces; D016022:Case-Control Studies; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology; D008297:Male; D020370:Osteoarthritis, Knee / Q000503:physiopathology / Q000628:therapy*
keywords: gait analysis; hip; joint angles; knee; knee brace; moments; pelvis