title: Quadriceps muscle strength, radiographic knee osteoarthritis and knee pain: the ROAD study.
abstract: BACKGROUND
  The objective of this study was to clarify the association of quadriceps muscle strength with knee pain using a large-scale, population-based cohort of the Research on Osteoarthritis/osteoporosis Against Disability (ROAD) study.
  
  
  METHODS
  From the 2566 subjects at the third visit of the ROAD study, the present study analyzed 2152 subjects who completed radiographic examinations and measurements of muscle strength and mass (690 men and 1462 women; mean age, 71.6 ± 12.2 years). Knee pain was assessed by an experienced orthopedist. Knee osteoarthritis (OA) was defined according to Kellgren-Lawrence (KL) grade. Quadriceps muscle strength and muscle mass at the lower limbs were measured by the Quadriceps Training Machine (QTM-05F, Alcare Co., Ltd. Tokyo, Japan) and the Body Composition Analyzer MC-190 (Tanita Corp., Tokyo, Japan), respectively.
  
  
  RESULTS
  Quadriceps muscle strength and weight bearing index (WBI: quadriceps muscle strength by weight) were significantly associated with knee pain after adjustment for age and body mass index, whereas grip strength and muscle mass at the lower limbs were not. The significant association of quadriceps muscle strength with knee pain was independent of radiographic knee OA.
  
  
  CONCLUSIONS
  The present cross-sectional study showed an independent association of quadriceps muscle strength with knee pain.
authors.affiliation: Department of Clinical Motor System Medicine, 22nd Century Medical & Research Center, Faculty of Medicine, the University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo, 113-8655, Japan. murakis-ort@h.u-tokyo.ac.jp.
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Muraki
authors.affiliation: National Rehabilitation Center for Persons with Disabilities, Saitama, Japan. akune-tky@umin.ac.jp.
authors.forename: Toru
authors.initials: T
authors.lastname: Akune
authors.affiliation: Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama, Japan. masa_bomgoo7@yahoo.co.jp.
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Teraguchi
authors.affiliation: Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama, Japan. rkagochan19821230@yahoo.co.jp.
authors.forename: Ryohei
authors.initials: R
authors.lastname: Kagotani
authors.affiliation: Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama, Japan. asawaka79@yahoo.co.jp.
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Asai
authors.affiliation: Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama, Japan. myoshida@wakayama-med.ac.jp.
authors.forename: Munehito
authors.initials: M
authors.lastname: Yoshida
authors.affiliation: Department of Orthopaedic Surgery, Tokyo Geriatric Medical Center, Tokyo, Japan. humiaki_tokimura@tmghig.jp.
authors.forename: Fumiaki
authors.initials: F
authors.lastname: Tokimura
authors.affiliation: Department of Orthopaedic Surgery, Faculty of Medicine, the University of Tokyo, Tokyo, Japan. tanakas-ort@h.u-tokyo.ac.jp.
authors.forename: Sakae
authors.initials: S
authors.lastname: Tanaka
authors.affiliation: Department of Medical Research and Management for Musculoskeletal Pain, 22nd Century Medical & Research Center, Faculty of Medicine, the University of Tokyo, Tokyo, Japan. okah-tky@umin.ac.jp.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Oka
authors.affiliation: Department of Orthopaedic Surgery, Japan Community Health care Organization Tokyo Shinjuku Medical Center, Tokyo, Japan. kawaguchi-ort@h.u-tokyo.ac.jp.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kawaguchi
authors.affiliation: National Rehabilitation Center for Persons with Disabilities, Saitama, Japan. kozo-nakamura-62@jcom.home.ne.jp.
authors.forename: Kozo
authors.initials: K
authors.lastname: Nakamura
authors.affiliation: Department of Joint Disease Research, 22nd Century Medical & Research Center, Faculty of Medicine, the University of Tokyo, Tokyo, Japan. yoshimuran-ort@h.u-tokyo.ac.jp.
authors.forename: Noriko
authors.initials: N
authors.lastname: Yoshimura
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D018771:Arthralgia / Q000453:epidemiology / Q000503:physiopathology*; D044466:Asian People; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000503:physiopathology*; D011446:Prospective Studies; D052097:Quadriceps Muscle / Q000502:physiology*; D011859:Radiography