title: Muscle volume compared to cross-sectional area is more appropriate for evaluating muscle strength in young and elderly individuals.
abstract: OBJECTIVE
  the present study examined which of muscle volume (MV) and cross-sectional area (CSA) is appropriate for evaluating the relation with elbow flexor muscle strength in young and elderly individuals.
  
  
  METHODS
  the subjects were 52 young (20-34 year; 30 men and 22 women) and 51 elderly individuals (60-77 year, 19 men and 32 women). The MV and maximal anatomical CSA (ACSA) of elbow flexors were determined by magnetic resonance imaging. The torque developed during maximal voluntary contraction of isometric elbow joint flexion was converted to force by dividing it by the forearm length of each subject.
  
  
  RESULTS
  torque was significantly correlated with MV in young and elderly individuals (r = 0.564-0.926). Similarly, force was also significantly correlated with ACSA in each of them (r = 0.637-0.906). However, the y-intercepts of the regression lines for the ACSA-force relationship in young men and women were significantly higher than zero. There was no age effect on torque per MV, whereas force per ACSA was significantly higher in young adults than in elderly individuals.
  
  
  CONCLUSIONS
  for elbow flexors, MV compared to ACSA is appropriate for evaluating the size-strength relationship and the existence of age-related difference in muscle strength per size.
authors: Japan Society for the Promotion of Science, Japan. carp_crespo_0522@ruri.waseda.jp
authors: Ryota
authors: R
authors: Akagi
authors: Yohei
authors: Y
authors: Takai
authors: Megumi
authors: M
authors: Ohta
authors: Hiroaki
authors: H
authors: Kanehisa
authors: Yasuo
authors: Y
authors: Kawakami
authors: Tetsuo
authors: T
authors: Fukunaga
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D004551:Elbow Joint / Q000502:physiology; D005260:Female; D015577:Geriatric Assessment / Q000379:methods*; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength / Q000502:physiology*; D018482:Muscle, Skeletal / Q000033:anatomy & histology* / Q000502:physiology*; D019415:Torque; D055815:Young Adult