title: Power at hip, knee and ankle joints are compromised in women with mild and moderate knee osteoarthritis.
abstract: BACKGROUND
  Analyses of the biomechanical characteristics of gait of women with mild and moderate knee osteoarthritis may identify parameters that could be targeted by physical therapy interventions. Therefore, the purpose of the present study was to compare the joint power profiles during gait between a group of elderly women with mild and moderate levels of knee osteoarthritis and a group of age-matched asymptomatic women.
  
  
  METHODS
  Thirty-nine women diagnosed with osteoarthritis at the medial compartment of the knee and 39 healthy women with no diagnosis of knee osteoarthritis participated in the study. Joint power profiles of the hip, knee and ankle joints in the sagittal plane during gait were performed using video and force data obtained using Qualisys ProReflex System synchronized with two force plates. Principal component analysis was applied to extract features from the joint power waveforms characterizing their main modes of temporal variation. The extracted features were compared between groups.
  
  
  RESULTS
  Women with knee osteoarthritis absorbed and generated less energy at the hip and ankle joints, and absorbed less energy at the knee when compared to the asymptomatic group.
  
  
  CONCLUSIONS
  The observed power pattern in women with knee osteoarthritis may be related to their reduced gait speed, a suboptimal strategy possibly used to reduce reaction forces at the knee. Clinical studies should investigate whether interventions designed to improve muscular resources, as a means to control the flow of forces at the knee, would optimize power patterns and gait performance in women with knee osteoarthritis.
authors.affiliation: Department of Physical Therapy, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil. renanresende@hotmail.com
authors.forename: Renan Alves
authors.initials: RA
authors.lastname: Resende
authors.forename: Sérgio Teixeira
authors.initials: ST
authors.lastname: Fonseca
authors.forename: Paula Lanna
authors.initials: PL
authors.lastname: Silva
authors.forename: Claudio Marcos Bedran
authors.initials: CM
authors.lastname: Magalhães
authors.forename: Renata Noce
authors.initials: RN
authors.lastname: Kirkwood
mesh_terms: D000368:Aged; D000843:Ankle Joint / Q000503:physiopathology*; D001696:Biomechanical Phenomena; D003430:Cross-Sectional Studies; D005260:Female; D005684:Gait / Q000502:physiology*; D006621:Hip Joint / Q000503:physiopathology*; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology*; D008875:Middle Aged; D015999:Multivariate Analysis; D053580:Muscle Strength / Q000502:physiology*; D020370:Osteoarthritis, Knee / Q000503:physiopathology*; D025341:Principal Component Analysis