title: Impaired varus-valgus proprioception and neuromuscular stabilization in medial knee osteoarthritis.
abstract: Impaired proprioception and poor muscular stabilization in the frontal plane may lead to knee instability during functional activities, a common complaint in persons with knee osteoarthritis (KOA). Understanding these frontal plane neuromechanical properties in KOA will help elucidate the factors contributing to knee instability and aid in the development of targeted intervention strategies. The objectives of the study were to compare knee varus-valgus proprioception, isometric muscle strength, and active muscular contribution to stability between persons with medial KOA and healthy controls. We evaluated knee frontal plane neuromechanical parameters in 14 participants with medial KOA and 14 age- and gender-matched controls, using a joint driving device (JDD) with a customized motor and a 6-axis force sensor. Analysis of covariance with BMI as a covariate was used to test the differences in varus-valgus neuromechanical parameters between these two groups. The KOA group had impaired varus proprioception acuity (1.08±0.59° vs. 0.69±0.49°, p<0.05), decreased normalized varus muscle strength (1.31±0.75% vs. 1.79±0.84% body weight, p<0.05), a trend toward decreased valgus strength (1.29±0.67% vs. 1.88±0.99%, p=0.054), and impaired ability to actively stabilize the knee in the frontal plane during external perturbation (4.67±2.86 vs. 8.26±5.95 Nm/degree, p<0.05). The knee frontal plane sensorimotor control system is compromised in persons with medial KOA. Our findings suggest varus-valgus control deficits in both the afferent input (proprioceptive acuity) and muscular effectors (muscle strength and capacity to stabilize the joint).
authors: Department of Physical Therapy and Human Movement Sciences, Northwestern University, United States. Electronic address: hsini@northwestern.edu.
authors: Alison H
authors: AH
authors: Chang
authors: Department of Biomedical Engineering, Northwestern University, United States. Electronic address: song-lee@northwestern.edu.
authors: Song Joo
authors: SJ
authors: Lee
authors: Sensory Motor Performance Program, Rehabilitation Institute of Chicago, United States. Electronic address: hengzhao@gmail.com.
authors: Heng
authors: H
authors: Zhao
authors: Sensory Motor Performance Program, Rehabilitation Institute of Chicago, United States. Electronic address: y-ren@northwestern.edu.
authors: Yupeng
authors: Y
authors: Ren
authors: Department of Biomedical Engineering, Northwestern University, United States; Sensory Motor Performance Program, Rehabilitation Institute of Chicago, United States; Department of Orthopaedic Surgery, Northwestern University, United States; Department of Physical Medicine and Rehabilitation, Northwestern University, United States. Electronic address: l-zhang@northwestern.edu.
authors: Li-Qun
authors: LQ
authors: Zhang
mesh_terms: D000328:Adult; D000368:Aged; D001696:Biomechanical Phenomena; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000503:physiopathology; D007719:Knee Joint / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength / Q000502:physiology; D020370:Osteoarthritis, Knee / Q000503:physiopathology*; D011434:Proprioception / Q000502:physiology*; D016059:Range of Motion, Articular / Q000502:physiology
keywords: Instability; Knee osteoarthritis; Proprioception; Varus–valgus motion