title: Ultrasonographic assessment of medial femoral cartilage deformation acutely following walking and running.
abstract: To determine the magnitude of medial femoral cartilage deformation using ultrasonography (US) following walking and running in healthy individuals.
  
  
  
  Twenty-five healthy participants with no history of osteoarthritis or knee injury volunteered for this study. Medial femoral cartilage thickness was assessed using US before and after three separate 30-min loading conditions: (1) walking at a self-selected speed, (2) running at a self-selected speed, and (3) sitting on a treatment table (i.e., control). Cartilage deformation was calculated as the percent change score from pre to post loading in each loading condition. The magnitude of cartilage deformation was compared between the three loading conditions.
  
  
  
  There was no difference in baseline cartilage thickness between the three sessions (F1,24= 0.18, P = 0.68). Cartilage deformation was different between the loading conditions (F1,24= 47.54, P < 0.001). The walking (%Δ = -6.7, t24= 6.90, P < 0.001, d = -1.92) and running (%Δ = -8.9, t24= 8.14, P < 0.001, d = -1.85) conditions resulted in greater cartilage deformation when compared to the control condition (%Δ = +3.4). There was no difference in cartilage deformation between the running and walking conditions (t24= 1.10, P = 0.28, d = 0.33). US measured medial femoral cartilage thickness demonstrated reliability and precision within a single session (ICC2,k= 0.966, SEM = 0.07 mm) and between additional sessions separated by seven (ICC2,k= 0.964, SEM = 0.08 mm) and 16 days (ICC2,k= 0.919, SEM = 0.11 mm).
  
  
  
  US demonstrated to be a reliable and sensitive imaging modality at quantifying medial femoral cartilage deformation in healthy individuals. Both walking and running conditions created greater cartilage deformation when compared to the control conditions, but no difference was observed between the walking and running conditions.
authors.affiliation: Department of Exercise and Sports Science, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States; Human Movement Science Curriculum, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States. Electronic address: Harkey@unc.edu.
authors.forename: M S
authors.initials: MS
authors.lastname: Harkey
authors.affiliation: Department of Exercise and Sports Science, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States. Electronic address: troyb@email.unc.edu.
authors.forename: J T
authors.initials: JT
authors.lastname: Blackburn
authors.affiliation: Department of Exercise and Sports Science, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States; Human Movement Science Curriculum, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States. Electronic address: davishc@live.unc.edu.
authors.forename: H
authors.initials: H
authors.lastname: Davis
authors.affiliation: Department of Exercise and Sports Science, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States. Electronic address: sierraar@live.unc.edu.
authors.forename: L
authors.initials: L
authors.lastname: Sierra-Arévalo
authors.affiliation: Department of Radiology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States. Electronic address: Daniel_nissman@med.unc.edu.
authors.forename: D
authors.initials: D
authors.lastname: Nissman
authors.affiliation: Department of Exercise and Sports Science, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States. Electronic address: brian@unc.edu.
authors.forename: B
authors.initials: B
authors.lastname: Pietrosimone
mesh_terms: D002358:Cartilage, Articular / Q000000981:diagnostic imaging* / Q000473:pathology / Q000502:physiology; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging* / Q000502:physiology; D008297:Male; D009929:Organ Size; D012420:Running / Q000502:physiology*; D014463:Ultrasonography; D016138:Walking / Q000502:physiology*; D016474:Weight-Bearing / Q000502:physiology*; D055815:Young Adult
keywords: Cartilage thickness; Knee; Loading; Ultrasound