title: Quantitative Elastosonography of the Myotendinous Junction: Normal Behavior and Correlation With a Standard Measurement System During Functional Tests.
abstract: OBJECTIVE
  In recent years, an increasing need to use imaging to assess normal and adaptive muscle function, in addition to its anatomy and structure, has emerged. We evaluated the myotendinous junction's elastosonographic behavior in light of the most recent literature on its physiologic behavior. The elastosonographic studies were compared with the results obtained from a standard measurement system to ensure a correlation with maximal muscle contraction.
  
  
  METHODS
  Nineteen male professional soccer players were assessed during functional tests. The participants performed 5 repetitions at 60°/s to assess muscle strength and 3 repetitions at 30°/s to assess the maximum force peak of thigh muscles. The participants were monitored by a strength-power measurement system and an ultrasound machine equipped with multifrequency (18-6-MHz) linear array transducers.
  
  
  RESULTS
  The 19 soccer players were aged between 19 and 34 years (mean age, 28 years). For the right rectus femoris, the results of the elastosonographic studies showed a mean elasticity value ± SD of 30.75% ± 10.05% with the muscle relaxed and a value of 13.75% ± 8.44% during contraction (mean decrease, 17.00% ± 11.71%). Elasticity values were 36.48% ± 8.39% before contraction and 8.77% ± 6.55% during contraction of the left rectus femoris muscle (mean decrease, 27.71% ± 11.95%). For 30° eccentric contraction of the left leg, correlation with the standard measurement system showed Pearson r values of -0.53 and -0.51 when comparing force peak and mean work, respectively, with elasticity values.
  
  
  CONCLUSIONS
  Our study shows that strain elastosonographic quantification of muscle elasticity seems to match the expected physiologic and biomechanical behavior of the myotendinous junction.
authors.affiliation: Department of Radiology, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico Policlinico San Matteo, Pavia, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Minafra
authors.affiliation: Department of Radiology, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico Policlinico San Matteo, Pavia, Italy.
authors.forename: Chandra
authors.initials: C
authors.lastname: Bortolotto
authors.affiliation: Mapei Sport Research Center, Olgiate Olona, Italy.
authors.forename: Ermanno
authors.initials: E
authors.lastname: Rampinini
authors.affiliation: Department of Radiology, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico Policlinico San Matteo, Pavia, Italy.
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Calliada
authors.affiliation: Nigrisoli Hospital, Bologna, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Monetti
mesh_terms: D000328:Adult; D056352:Athletes; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005069:Evaluation Studies as Topic; D006801:Humans; D007719:Knee Joint / Q000033:anatomy & histology / Q000502:physiology*; D008297:Male; D009119:Muscle Contraction / Q000502:physiology*; D053580:Muscle Strength / Q000502:physiology*; D018482:Muscle, Skeletal / Q000033:anatomy & histology / Q000502:physiology*; D012916:Soccer; D055815:Young Adult
keywords: elasticity; elasticity imaging techniques; isokinetic test; muscles; musculoskeletal ultrasound; strain elastosonography