title: Piriformis syndrome in knee osteoarthritis patients after wearing rocker bottom shoes.
abstract: BACKGROUND
  Rocker bottom shoes (RBS) are popular among patients with different foot, leg, or back problems in Korea. Patients with knee osteoarthritis concurrent weakness in the quadriceps femoris muscle, who wear these shoes, are often assumed to develop piriformis syndrome (PS). This study was performed to improve the understanding about the effect of wearing such shoes on duration of the syndrome in knee osteoarthritis.
  
  
  METHODS
  We randomly assigned 150 patients with PS, who had used RBS daily for at least 6 months, to 2 groups, the S (stopped wearing) and K (kept wearing) groups. Both the groups were subdivided into the O and N groups, comprising patients with and without knee osteoarthritis, respectively. The effects of the treatment, including piriformis muscle injections and a home exercise program, were compared between the 2 groups by using a flexion-adduction-internal rotation (FAIR) test, a numeric rating scale (NRS), and the revised Oswestry disability index (ODI) during the 12-week follow-up.
  
  
  RESULTS
  The positive FAIR test ratios, mean NRS scores, and revised ODIs were higher in the KO group than the SN group from 4?12 weeks after treatment.
  
  
  CONCLUSIONS
  RBS may extend duration of the PS in osteoarthritis patients.
authors.affiliation: Department of Anesthesia and Pain Medicine, School of Medicine, Pusan National University, Yangsan, Korea.
authors.forename: Gyeong Jo
authors.initials: GJ
authors.lastname: Byeon
authors.forename: Kyung Hoon
authors.initials: KH
authors.lastname: Kim