title: Three-dimensional knee kinematics in patients with a discoid lateral meniscus during gait.
abstract: BACKGROUND
  To date, the knee kinematics of a discoid lateral meniscus (DLM) has not been elucidated. The aim was to investigate the three-dimensional knee kinematics in knees with a DLM using gait analysis.
  
  
  METHODS
  Ten patients (mean: 14years) diagnosed with bilateral DLM and unilaterally symptomatic snapping as well as 10 healthy controls (mean: 23years) participated in the study. Each patient with a DLM had unilaterally snapping knee in full extension and deep flexion. The three-dimensional gait analysis was performed with the point cluster technique. All subjects were asked to walk on a level floor at the speed of their choice. In the sagittal plane, knee excursion was separately evaluated during the weight acceptance phase and the mid-stance phase. In the axial plane, knee excursion during the stance phase was assessed. Finally, knee excursion during the whole gait cycle was evaluated in the frontal plane. Statistical comparison was conducted between groups, and between both sides in the DLM group.
  
  
  RESULTS
  In the sagittal plane, knee excursions during the weight acceptance phase and the mid-stance phase were significantly smaller in the DLM group than in the control group; in addition, these were smaller on the symptomatic side than on the asymptomatic side in the DLM group. In the axial plane, knee excursion was also significantly smaller on the symptomatic side than on the asymptomatic side in the DLM group, whereas the frontal knee motion did not differ significantly.
  
  
  CONCLUSIONS
  Less knee motion in the sagittal plane may prevent snapping during extension and flexion in patients with a DLM.
  
  
  METHODS
  III.
authors.affiliation: Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo, Japan. Electronic address: kharatoh@yahoo.co.jp.
authors.forename: Kengo
authors.initials: K
authors.lastname: Harato
authors.affiliation: Department of Physical Therapy, International University of Health and Welfare, Mita Hospital, Tokyo, Japan.
authors.forename: Aiko
authors.initials: A
authors.lastname: Sakurai
authors.affiliation: Department of Physical Therapy, International University of Health and Welfare, Mita Hospital, Tokyo, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Kudo
authors.affiliation: Department of Clinical Biomechanics, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Takeo
authors.initials: T
authors.lastname: Nagura
authors.affiliation: Masumoto Sports Clinic, Tokyo, Japan.
authors.forename: Ko
authors.initials: K
authors.lastname: Masumoto
authors.affiliation: Faculty of Nursing and Medical Care, Keio University, Tokyo, Japan.
authors.forename: Toshiro
authors.initials: T
authors.lastname: Otani
authors.affiliation: Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Niki
mesh_terms: D000293:Adolescent; D000328:Adult; D001696:Biomechanical Phenomena; D002648:Child; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D021621:Imaging, Three-Dimensional; D007719:Knee Joint / Q000502:physiology / Q000503:physiopathology*; D008297:Male; D008592:Menisci, Tibial / Q000002:abnormalities / Q000503:physiopathology*; D016059:Range of Motion, Articular; D013647:Task Performance and Analysis; D055815:Young Adult
keywords: Discoid lateral meniscus; Gait analysis; Knee kinematics; Stiffening strategy