title: Youth baseball players with elbow and shoulder pain have both low back and knee pain: a cross-sectional study.
abstract: OBJECTIVE
  Serious arm injuries in youth baseball players have been increasing. Though a breakage in the kinetic chain could affect arm injuries, an association between arm injuries and insufficient support of the trunk and lower extremities is not well understood. The purpose of this study was to investigate the association of low back and knee pain with elbow and/or shoulder complaints among youth baseball players.
  
  
  METHODS
  A self-administered questionnaire and document informed consent were mailed to youth athletes belonging to the Miyagi Amateur Sports Association. Multiple logistic regression analysis was used to examine the association of low back and knee pain with elbow and/or shoulder pain at the time of the questionnaire. Variables considered in the models were as follows: sex, age, BMI, years of athletic experience, position, team level, the amount of practice, participating day in team practice and game per week, frequency of participation in games, and practice intensity.
  
  
  RESULTS
  The final study population was comprised 1582 youth baseball players (aged 6-15 years old, male 95.6 %) who had responded to the questionnaire. A total of 24.8 % (n = 381) had elbow and/or shoulder pain, whereas 8.5 % (n = 130) had low back pain and 13.1 % (n = 201) had knee pain. The prevalence of elbow and/or shoulder pain with concomitant low back and knee pain was 61.2 % (n = 82) and 51.9 % (n = 108) (p < 0.001), respectively. The presence of low back and knee pain was significantly associated with the prevalence of elbow and/or shoulder pain among youth baseball players [adjusted odds ratio (ORs): 4.31, 95 % confidence interval (95 % CI): 2.86-6.51, p < 0.001, and ORs: 2.92, 95 % CI: 2.09-4.09, p < 0.001, respectively]. For other variables, older age (10- and 11-year old: ORs: 1.73, 95 % CI 1.10-2.73, p = 0.018; 12-15 year old: ORs: 1.62, 95 % CI: 1.18-2.58, p = 0.006), pitcher (ORs: 1.46, 95 % CI: 1.10-1.94, p = 0.009), catcher (ORs: 1.69, 95 % CI: 1.24-2.31, p = 0.001,), and practice intensity (ORs: 1.58, 95 % CI: 1.22-2.06, p = 0.001) were significantly associated with elbow and/or shoulder pain.
  
  
  CONCLUSIONS
  Both low back and knee pain were significantly associated with elbow and/or shoulder pain in youth baseball players. Clinicians should check the complaints of the trunk and lower extremities as well as those of the elbow and shoulder for preventing severe injuries in youth baseball players. Level of Evidence III.
authors: Department of Orthopedic Surgery, Tohoku University School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai, 980-8574, Japan.
authors: Takuya
authors: T
authors: Sekiguchi
authors: Department of Orthopedic Surgery, Tohoku University School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai, 980-8574, Japan. hagi@med.tohoku.ac.jp.|Department of Medicine and Science in Sports and Exercise, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, 980-8575, Japan. hagi@med.tohoku.ac.jp.
authors: Yoshihiro
authors: Y
authors: Hagiwara
authors: Department of Medicine and Science in Sports and Exercise, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, 980-8575, Japan.|Division of Biomedical Engineering for Health and Welfare, Tohoku University Graduate School of Biomedical Engineering, 2-1 Seiryo-machi, Aoba-ku, Sendai, 980-8575, Japan.
authors: Haruki
authors: H
authors: Momma
authors: Department of Nursing, Faculty of Health Sciences, Tohoku Fukushi University, 1-8-1 Kunimi, Aoba-ku, Sendai, 981-8522, Japan.|Division of Oral Diagnosis, Tohoku University Graduate School of Dentistry, 4-1 Seiryo-machi, Aoba-ku, Sendai, 980-8575, Japan.
authors: Masahiro
authors: M
authors: Tsuchiya
authors: Department of Medicine and Science in Sports and Exercise, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, 980-8575, Japan.|Department of Rehabilitation, Tohoku Fukushi University, 1-8-1 Kunimi, Aoba-ku, Sendai, 981-8522, Japan.
authors: Kaoru
authors: K
authors: Kuroki
authors: Department of Orthopedic Surgery, Tohoku University School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai, 980-8574, Japan.
authors: Kenji
authors: K
authors: Kanazawa
authors: Department of Orthopedic Surgery, Tohoku University School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai, 980-8574, Japan.
authors: Yutaka
authors: Y
authors: Yabe
authors: Department of Orthopedic Surgery, Tohoku University School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai, 980-8574, Japan.
authors: Masashi
authors: M
authors: Koide
authors: Department of Orthopedic Surgery, Tohoku University School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai, 980-8574, Japan.
authors: Nobuyuki
authors: N
authors: Itaya
authors: Department of Orthopedic Surgery, Tohoku University School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai, 980-8574, Japan.
authors: Eiji
authors: E
authors: Itoi
authors: Department of Medicine and Science in Sports and Exercise, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, 980-8575, Japan.|Division of Biomedical Engineering for Health and Welfare, Tohoku University Graduate School of Biomedical Engineering, 2-1 Seiryo-machi, Aoba-ku, Sendai, 980-8575, Japan.
authors: Ryoichi
authors: R
authors: Nagatomi
mesh_terms: D000293:Adolescent; D001134:Arm Injuries / Q000150:complications / Q000453:epidemiology; D056352:Athletes; D001265:Athletic Injuries / Q000150:complications / Q000453:epidemiology; D001484:Baseball / Q000293:injuries*; D002648:Child; D003430:Cross-Sectional Studies; D006801:Humans; D007564:Japan / Q000453:epidemiology; D007718:Knee Injuries / Q000150:complications / Q000453:epidemiology*; D017116:Low Back Pain / Q000150:complications / Q000453:epidemiology*; D008297:Male; D012307:Risk Factors; D012782:Shoulder; D020069:Shoulder Pain / Q000150:complications / Q000453:epidemiology*; D013177:Sports; D000092464:Elbow Injuries
keywords: Elbow pain; Epidemiological study; Lower extremity; Shoulder pain; Trunk; Youth baseball