title: Trunk muscles strength as a risk factor for nonspecific low back pain: a pilot study.
abstract: OBJECTIVE
  To investigate the effects of asymptomatic back muscle weakness and spinal deformity on low back pain (LBP).
  
  
  METHODS
  Sixty healthy subjects without LBP participated in this study. Radiography and an isokinetic/isometric dynamometer were used to respectively measure spinal scoliosis/lordosis and the strength of the trunk flexors/extensors. After 2 years, 48 subjects visited the hospital again and LBP episodes, its severity and the Korean version of the Oswestry Disability Index were assessed. Differences between the group with LBP and the group without LBP were evaluated and the association with LBP incidence and severity was determined.
  
  
  RESULTS
  Sex, age, and trunk strength were significantly different in both group. Sex and age were significantly positive associated with LBP incidence. The isometric trunk flexor and extensor strength, maximum isokinetic trunk flexor and extensor strength were significantly and negatively associated with the LBP severity. The maximum isokinetic trunk extensor and maximum isometric trunk extensor strength was significantly negative associated with the LBP incidence.
  
  
  CONCLUSIONS
  LBP incidence is associated with isometric and isokinetic trunk extensor weakness, whereas LBP severity is associated with age, sex, isokinetic trunk extensor and flexor weakness, isometric trunk extensor and flexor weakness.
authors.affiliation: Department of Rehabilitation Medicine, Chungnam National University School of Medicine, Daejeon, Korea.
authors.forename: Kang Hee
authors.initials: KH
authors.lastname: Cho
authors.affiliation: Department of Rehabilitation Medicine, Chungnam National University School of Medicine, Daejeon, Korea.
authors.forename: Jae Won
authors.initials: JW
authors.lastname: Beom
authors.affiliation: Department of Rehabilitation Medicine, Yuseong Wellness Rehabilitation Hospital, Daejeon, Korea.
authors.forename: Tae Sung
authors.initials: TS
authors.lastname: Lee
authors.affiliation: Department of Rehabilitation Medicine, Chungnam National University School of Medicine, Daejeon, Korea.
authors.forename: Jun Ho
authors.initials: JH
authors.lastname: Lim
authors.affiliation: Department of Rehabilitation Medicine, Chungnam National University School of Medicine, Daejeon, Korea.
authors.forename: Tae Heon
authors.initials: TH
authors.lastname: Lee
authors.affiliation: Department of Rehabilitation Medicine, Chungnam National University School of Medicine, Daejeon, Korea.
authors.forename: Ji Hyun
authors.initials: JH
authors.lastname: Yuk
keywords: Age; Low back pain; Muscle strength dynamometer; Muscle weakness; Sex