title: Effect of maturation on muscle quality of the lower limb muscles in adolescent boys.
abstract: BACKGROUND
  The purpose of this study was to clarify the effect of maturation on the muscle quality of the lower limb muscles around puberty.
  
  
  METHODS
  Subjects were 117 Japanese boys age 12 to 15 years. The maturity status was assessed by using a self-assessment of stage of pubic hair development based on the criteria of Tanner. On the basis of the criteria, subjects were divided into the prepubescent or pubescent group. Muscle thickness of knee extensors and plantar flexors were measured by a B-mode ultrasound. Muscle volume index (MV) was calculated from muscle thickness and limb length. Maximal voluntary isometric joint toques (TQ) of knee extension and ankle plantar flexion were measured using a myometer. Muscle quality was derived from dividing TQ by MV (TQ/MV).
  
  
  RESULTS
  In both muscles, TQ-MV relationships were also similar between the prepubescent and pubescent groups, and there was no significant difference in TQ/MV between the two groups when chronological age was statistically adjusted.
  
  
  CONCLUSIONS
  The current results indicate that, for adolescent boys, the muscle quality of the lower limb muscles is not significantly influenced by maturation.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Fukunaga
authors.affiliation: National Institute of Fitness and Sports in Kanoya, 1 Shiromizu, Kanoya, Kagoshima 8912393, Japan. y-takai@nifs-k.ac.jp.
authors.forename: Yohei
authors.initials: Y
authors.lastname: Takai
authors.forename: Takaya
authors.initials: T
authors.lastname: Yoshimoto
authors.forename: Eiji
authors.initials: E
authors.lastname: Fujita
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Yamamoto
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kanehisa
mesh_terms: D000293:Adolescent; D002648:Child; D006801:Humans; D007564:Japan; D016014:Linear Models; D035002:Lower Extremity / Q000502:physiology*; D008297:Male; D053580:Muscle Strength / Q000502:physiology*; D012741:Sexual Maturation / Q000502:physiology*