title: Relationships between the center of pressure and the movements of the ankle and knee joints during the stance phase in patients with severe medial knee osteoarthritis.
abstract: BACKGROUND
  The knee joint movement during the stance phase is affected by altered ankle movement and the center of pressure (COP). However the relationships between changes in the center of pressure (COP) and the altered kinematics and kinetics of the ankle and knee joints in patients with osteoarthritis (OA) of the knee are not well understood. The purpose of this study was to determine the relationships between changes in the COP and the altered kinematic and kinetic variables in ankle and knee joints during the stance phase in patients with medial knee OA.
  
  
  METHODS
  Fourteen patients with knee OA (21 knees) and healthy subjects were assessed by gait analysis using an eight-camera motion analysis system to record forward and lateral shifts in the COP and the angle and net internal moments of the knee and ankle joint. Spearman rank-correlation coefficients were used to determine the relationship between these results.
  
  
  RESULTS
  In knees with medial OA, lateral shifts in the COP were correlated with knee flexion angle. Lateral shifts in the COP were correlated with the second peak of the knee extensor moment and correlated with the knee abductor moment.
  
  
  CONCLUSIONS
  In patients with medial knee OA, lateral shifts in the COP were negatively correlated with the kinematic and kinetic variables in the sagittal plane of the knee joints. Controlling such lateral shifts in the COP may thus be an effective intervention for mechanical loads on the knee during the stance phase in patients with knee OA.
authors.affiliation: Department of Physical Therapy, Faculty of Health Sciences, Tsukuba International University, Ibaraki, Japan. Electronic address: t-fukaya@tius.ac.jp.
authors.forename: Takashi
authors.initials: T
authors.lastname: Fukaya
authors.affiliation: Center for Medical Sciences, Ibaraki Prefectural University of Health Sciences, Ibaraki, Japan.
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Mutsuzaki
authors.affiliation: Department of Radiological Sciences, Ibaraki Prefectural University of Health Sciences, Ibaraki, Japan.
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Okubo
authors.affiliation: Department of Radiological Sciences, Ibaraki Prefectural University of Health Sciences, Ibaraki, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Mori
authors.affiliation: Center for Medical Sciences, Ibaraki Prefectural University of Health Sciences, Ibaraki, Japan.
authors.forename: Yasuyoshi
authors.initials: Y
authors.lastname: Wadano
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000843:Ankle Joint / Q000000981:diagnostic imaging* / Q000503:physiopathology; D001696:Biomechanical Phenomena; D005260:Female; D005684:Gait / Q000502:physiology*; D056305:Genu Varum / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging* / Q000503:physiopathology; D008297:Male; D009068:Movement / Q000502:physiology; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging* / Q000503:physiopathology; D011312:Pressure; D016059:Range of Motion, Articular; D013647:Task Performance and Analysis
keywords: Ankle; Center of pressure; Correlation; Knee; Moment