title: Investigation of the biomechanical effect of variable stiffness shoe on external knee adduction moment in various dynamic exercises.
abstract: BACKGROUND
  The growing ageing population and high prevalence of knee osteoarthritis (OA) in athletes across nations have created a strong demand for improved non-invasive therapeutic alternatives for knee OA. The aim of this study is to investigate the effect of the variable stiffness shoe (VSS), a new non-invasive therapeutic approach, on external knee adduction moment (EKAM) in various dynamic exercises. EKAM is believed to have positive correlation with the progression and development of knee OA.
  
  
  METHODS
  Thirty young participants (16 male and 14 female; age 22.6 ± 1.9 years) from National University of Singapore were enrolled in this study. The tested activities were walking, running, drop-landing, and lateral hopping. All the dynamic exercises were recorded simultaneously by the 8-camera VICON Motion Systems (Oxford Metric, UK) with a sampling rate of 100 Hz.
  
  
  RESULTS
  The results showed that the EKAM was reduced in all the dynamic exercises with the use of VSS. The VSS produced significant reductions in the peak EKAM during walking (4.97%, p = 0.039), running (11.15%, p = 0.011), drop-landing (11.18%, p = 0.038) and lateral hopping (17.34%, p = 0.023) as compared to the control shoe.
  
  
  CONCLUSIONS
  The reduction of EKAM with the use of VSS in various dynamic exercises demonstrates its potential in delaying the onset and the progression of knee OA in early stage of knee OA patients.
authors.affiliation: Department of Bioengineering, Faculty of Engineering, National University of Singapore, Block E3A #07-15, 7 Engineering Drive 1, Singapore 117574, Singapore. bielt@nus.edu.sg.
authors.forename: Jee Chin
authors.initials: JC
authors.lastname: Teoh
authors.forename: Jin Huat
authors.initials: JH
authors.lastname: Low
authors.forename: Ying Bena
authors.initials: YB
authors.lastname: Lim
authors.forename: Victor Phyau-Wui
authors.initials: VP
authors.lastname: Shim
authors.forename: Jaeyoung
authors.initials: J
authors.lastname: Park
authors.forename: Seung-Bum
authors.initials: SB
authors.lastname: Park
authors.forename: Sang Jun
authors.initials: SJ
authors.lastname: Park
authors.forename: Taeyong
authors.initials: T
authors.lastname: Lee
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