title: Lumbar intervertebral disk degeneration in elite competitive swimmers: a case control study.
abstract: BACKGROUND
  The majority of orthopaedic problems experienced by competitive swimmers are related to pain in the shoulder, low back, and knee. Three of 39 national swim team members were hampered in their performance due to lumbar disk herniation at an international competition in 2001. There has been no previous research into lumbar disk degeneration in elite competitive swimmers.
  
  
  OBJECTIVE
  Excessive competitive swimming activities accelerate lumbar disk degeneration.
  
  
  METHODS
  Case control study; Level of evidence, 3.
  
  
  METHODS
  Fifty-six elite swimmers (high-load group, 35 men and 21 women; mean age, 19.6 years) and a control group of 38 university recreational level swimmers (low-load group, 24 men and 14 women; mean age, 21.1 years) were evaluated for lumbar disk degeneration using magnetic resonance imaging. We compared the prevalence of disk degeneration and the disk level between the 2 groups and further investigated the relationship among their symptoms, swimming styles, and disk degeneration.
  
  
  RESULTS
  Thirty-eight (68%) elite swimmers and 11 (29%) controls had degenerated disks at various disk levels, and the prevalence was significantly greater in the elite swimmers (P = .0002). Comparison between the 2 groups of the prevalence of disk degeneration at each level revealed that the disk level of L5-S1 was significantly more frequently degenerated in the high-load group (P = .026). There was no significant relationship observed among the variables of low back pain symptoms, swimming strokes, and disk degeneration.
  
  
  CONCLUSIONS
  Excessive competitive swimming activities might exaggerate lumbar intervertebral disk degeneration, especially in the L5-S1 intervertebral segment.
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8575, Japan. seikei@md.tsukuba.ac.jp
authors.forename: Koji
authors.initials: K
authors.lastname: Kaneoka
authors.forename: Ken
authors.initials: K
authors.lastname: Shimizu
authors.forename: Mika
authors.initials: M
authors.lastname: Hangai
authors.forename: Toru
authors.initials: T
authors.lastname: Okuwaki
authors.forename: Naotaka
authors.initials: N
authors.lastname: Mamizuka
authors.forename: Masataka
authors.initials: M
authors.lastname: Sakane
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Ochiai
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007403:Intervertebral Disc / Q000473:pathology*; D007564:Japan; D008161:Lumbosacral Region / Q000473:pathology*; D008297:Male; D013122:Spinal Diseases / Q000175:diagnosis / Q000209:etiology; D013177:Sports; D013550:Swimming