title: Non-invasive assessment of muscle stiffness in patients with Duchenne muscular dystrophy.
abstract: BACKGROUND
  Assessment of muscle mechanical properties may provide clinically valuable information for follow-up of patients with Duchenne muscular dystrophy (DMD) through the course of their disease. In this study we aimed to assess the effect of DMD on stiffness of relaxed muscles using elastography (supersonic shear imaging).
  
  
  METHODS
  Fourteen DMD patients and 13 control subjects were studied. Six muscles were measured at 2 muscle lengths (shortened and stretched): gastrocnemius medialis (GM); tibialis anterior (TA); vastus lateralis (VL); biceps brachii (BB); triceps brachii (TB); and abductor digiti minimi (ADM).
  
  
  RESULTS
  Stiffness was significantly higher in DMD patients compared with controls for all the muscles (main effect for population, P < 0.033 in all cases), except for ADM. The effect size was small (d = 0.33 for ADM at both muscle lengths) to large (d = 0.86 for BB/stretched).
  
  
  CONCLUSIONS
  Supersonic shear imaging is a sensitive non-invasive technique to assess the increase in muscle stiffness associated with DMD.
authors.affiliation: Laboratory "Motricité, Interactions, Performance" (EA 4334), University of Nantes, UFR STAPS, 25 bis boulevard Guy Mollet, BP 72206, 44322 Nantes cedex 3, France.
authors.forename: Lilian
authors.initials: L
authors.lastname: Lacourpaille
authors.forename: François
authors.initials: F
authors.lastname: Hug
authors.forename: Arnaud
authors.initials: A
authors.lastname: Guével
authors.forename: Yann
authors.initials: Y
authors.lastname: Péréon
authors.forename: Armelle
authors.initials: A
authors.lastname: Magot
authors.forename: Jean-Yves
authors.initials: JY
authors.lastname: Hogrel
authors.forename: Antoine
authors.initials: A
authors.lastname: Nordez
mesh_terms: D000293:Adolescent; D000704:Analysis of Variance; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D054459:Elasticity Imaging Techniques; D005260:Female; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology*; D008297:Male; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging / Q000503:physiopathology*; D020388:Muscular Dystrophy, Duchenne / Q000000981:diagnostic imaging / Q000473:pathology*; D014463:Ultrasonography; D055815:Young Adult
keywords: elastography; evaluation; myopathy; shear elastic modulus; supersonic shear imaging