title: Biomechanics of running with rocker shoes.
abstract: OBJECTIVE
  Load reduction is an important consideration in conservative management of tendon overuse injuries such as Achilles tendinopathy. Previous research has shown that the use of rocker shoes can reduce the positive ankle power and plantar flexion moment which might help in unloading the Achilles tendon. Despite this promising implication of rocker shoes, the effects on hip and knee biomechanics remain unclear. Moreover, the effect of wearing rocker shoes on different running strike types is unexplored. The aim of this study was to investigate biomechanics of the ankle, knee and hip joints and the role of strike type on these outcomes.
  
  
  METHODS
  Randomized cross-over study.
  
  
  METHODS
  In this study, 16 female endurance runners underwent three-dimensional gait analysis wearing rocker shoes and standard shoes. We examined work, moments, and angles of the ankle, knee and hip during the stance phase of running.
  
  
  RESULTS
  In comparison with standard shoes, running with rocker shoes significantly (p<0.001) reduced the positive (16%), and negative (32%) work at the ankle joint. Plantar flexion moment peak and impulse were also reduced by 11% and 12%, respectively. Reduction in these variables was almost two times larger for midfoot strikers than for rearfoot strikers. At the knee joint running with rocker shoes significantly increased the positive work (14%), extension moment peak (6%), and extension moment impulse (12%).
  
  
  CONCLUSIONS
  These findings indicate that although running with rocker shoes might lower mechanical load on the Achilles tendon, it could increase the risk of overuse injuries of the knee joint.
authors.affiliation: Department of Rehabilitation Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands; Department of Physiotherapy, School of Rehabilitation Sciences, Shiraz University of Medical Sciences, Shiraz, Iran. Electronic address: sobhan132@gmail.com.
authors.forename: Sobhan
authors.initials: S
authors.lastname: Sobhani
authors.affiliation: Department of Epidemiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
authors.forename: Edwin R
authors.initials: ER
authors.lastname: van den Heuvel
authors.affiliation: Department of Rehabilitation Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands; Center for Sports Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: Rienk
authors.initials: R
authors.lastname: Dekker
authors.affiliation: Department of Rehabilitation Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: Klaas
authors.initials: K
authors.lastname: Postema
authors.affiliation: Center for Sports Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: Bas
authors.initials: B
authors.lastname: Kluitenberg
authors.affiliation: Center for Sports Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: Steef W
authors.initials: SW
authors.lastname: Bredeweg
authors.affiliation: Department of Rehabilitation Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: Juha M
authors.initials: JM
authors.lastname: Hijmans
mesh_terms: D000125:Achilles Tendon / Q000502:physiology*; D000328:Adult; D000843:Ankle Joint / Q000502:physiology*; D001696:Biomechanical Phenomena; D018592:Cross-Over Studies; D012090:Cumulative Trauma Disorders / Q000517:prevention & control; D005260:Female; D005528:Foot / Q000502:physiology; D006621:Hip Joint / Q000502:physiology*; D006801:Humans; D007719:Knee Joint / Q000502:physiology*; D011897:Random Allocation; D012420:Running / Q000502:physiology*; D012775:Shoes; D055815:Young Adult
keywords: Footwear; Gait analysis; Rocker bottom; Rocker sole; Running