title: Comparisons of ultrasound-estimated intramuscular fat with fitness and health indicators.
abstract: We examined ultrasound-estimated intramuscular fat of 4 muscles: rectus femoris (RF), biceps femoris (BF), tibialis anterior (TA), and medial gastrocnemius (MG), and compared the results with other health measures.
  
  
  
  Forty-two participants were tested. Muscle echo intensity was quantified into percent intramuscular fat using previously published equations.
  
  
  
  Strong correlations were found in percent intramuscular fat in the 4 muscles (r ≥ 0.8). Weak to moderate correlations were found between intramuscular fat and body mass index (r ≥ 0.2), waist/hip ratio (r ≥ 0.2), muscle thickness (r = -0.5 in RF, r = -0.4 in TA, r = -0.7 in MG), and muscle strength (leg extension: r = 0.4; leg flexion: r = -0.5). A relationship between intramuscular fat in RF and MG and physical activity was also observed (P < 0.05).
  
  
  
  Ultrasound-estimated intramuscular fat was associated with other health measures and may provide physiological insight into the health consequences of obesity. Muscle Nerve 54: 743-749, 2016.
authors.affiliation: Department of Kinesiology, University of Georgia, Athens, Georgia, USA. younghuiju@gmail.com.
authors.forename: Hui-Ju
authors.identifier: 0000-0001-6115-4650
authors.initials: HJ
authors.lastname: Young
authors.affiliation: Department of Kinesiology, University of Georgia, Athens, Georgia, USA.
authors.forename: William M
authors.initials: WM
authors.lastname: Southern
authors.affiliation: Department of Kinesiology, University of Georgia, Athens, Georgia, USA.
authors.forename: Kevin K
authors.initials: KK
authors.lastname: Mccully
mesh_terms: D000273:Adipose Tissue / Q000000981:diagnostic imaging* / Q000502:physiology*; D000328:Adult; D000368:Aged; D005260:Female; D006304:Health Status; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging* / Q000502:physiology*; D010809:Physical Fitness / Q000502:physiology*; D014463:Ultrasonography / Q000379:methods / Q000592:standards*; D055815:Young Adult
keywords: body composition; health and fitness; muscle composition; muscle health; ultrasound echo intensity; ultrasound-estimated intramuscular fat