title: The impact of faulty posture on rotator cuff tears with and without symptoms.
abstract: OBJECTIVE
  We hypothesized that the prevalence of rotator cuff tears would be higher among individuals with poor posture, regardless of the presence of symptoms.
  
  
  METHODS
  The study initially comprised 525 residents of a mountain village who participated in an annual health check. Participants completed a background questionnaire, and physical examinations were performed to evaluate shoulder function. Ultrasonographic examinations were also performed to identify rotator cuff tears, and participants were grouped according to the presence or absence of tears. Posture was classified by 2 observers into 4 types according to the classification of Kendall, as follows: ideal alignment, kyphotic-lordotic posture, flat-back posture, and sway-back posture. Univariate analyses were performed to compare differences in background characteristics between groups, then multivariate analysis was performed to identify those factors associated with rotator cuff tears.
  
  
  RESULTS
  Final analysis was performed for 379 participants (135 men, 244 women; mean age, 62.0 years; range, 31-94 years) showing the same posture classification from both observers. Of these, 93 (24.5%) showed rotator cuff tear in one shoulder and 45 (11.9%) showed tears in both. Prevalence of rotator cuff tears was 2.9% with ideal alignment, 65.8% with kyphotic-lordotic posture, 54.3% with flat-back posture, and 48.9% with sway-back posture. Logistic regression analysis identified increased age, abnormal posture, and past pain as factors associated with rotator cuff tears.
  
  
  CONCLUSIONS
  Postural abnormality represented an independent predictor of both symptomatic and asymptomatic rotator cuff tears. These results may help define preventive measures for rotator cuff tears and in design ing rehabilitation therapies for shoulder disease.
authors.affiliation: Department of Orthopaedic Surgery, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan. Electronic address: a.yamamoto@gunma-u.ac.jp.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Yamamoto
authors.affiliation: Department of Orthopaedic Surgery, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Takagishi
authors.affiliation: Department of Physical Therapy, Takasaki University of Health and Welfare, Takasaki, Gunma, Japan.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Kobayashi
authors.affiliation: Department of Orthopaedic Surgery, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Shitara
authors.affiliation: Department of Orthopaedic Surgery, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Ichinose
authors.affiliation: Department of Orthopaedic Surgery, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan.
authors.forename: Eiji
authors.initials: E
authors.lastname: Takasawa
authors.affiliation: Department of Orthopaedic Surgery, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Shimoyama
authors.affiliation: Department of Orthopaedic Surgery, National Hospital Organization, Takasaki General Medical Center, Takasaki, Gunma, Japan.
authors.forename: Toshihisa
authors.initials: T
authors.lastname: Osawa
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011187:Posture; D016059:Range of Motion, Articular; D017006:Rotator Cuff / Q000503:physiopathology*; D000070636:Rotator Cuff Injuries; D012785:Shoulder Joint / Q000503:physiopathology; D013708:Tendon Injuries / Q000175:diagnosis / Q000503:physiopathology*
keywords: Rotator cuff tear; asymptomatic rotator cuff tear; epidemiology; etiology; faulty posture; population-based study