title: Work and power of the knee flexor and extensor muscles in patients with osteoarthritis and after total knee arthroplasty.
abstract: BACKGROUND
  The inflammatory manifestations of knee osteoarthritis (OA) lead to muscle inhibition and hypotrophy, resulting in a reduction in total muscle work and muscle power. Total knee arthroplasty (TKA) is the most adequate surgery for the treatment of advanced OA. However, its effects on muscle functional behavior have not been well understood.
  
  
  OBJECTIVE
  To compare the total work and power of the knee flexor and extensor muscles in patients with OA (20) and in patients post-TKA (12) at two angular velocities (60º/sec and 240º/sec).
  
  
  METHODS
  An isokinetic Biodex dynamometer was used to assess muscle power and total work during isokinetic contractions. Two-way ANOVA for repeated measures was used to compare total muscle work and muscle power between the groups (SPSS software, version 13.0; significance level, P < 0.05).
  
  
  RESULTS
  There was no difference between the OA and TKA groups for the total work of both knee extensors and flexors at the two angular velocities (P > 0.05). In addition, no difference was observed in the muscle power of the knee extensors and flexors (P > 0.05).
  
  
  CONCLUSIONS
  Total work and power were similar in the OA and TKA groups, suggesting that TKA did not improve functional capacity, which was similar in both groups.
authors.affiliation: Pontifícia Universidade Católica do Rio Grande do Sul.
authors.forename: Denise
authors.initials: D
authors.lastname: Bastiani
authors.forename: Cintia Helena
authors.initials: CH
authors.lastname: Ritzel
authors.forename: Silvia Manfrin
authors.initials: SM
authors.lastname: Bortoluzzi
authors.forename: Marco Aurelio
authors.initials: MA
authors.lastname: Vaz
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength; D018482:Muscle, Skeletal / Q000503:physiopathology*; D020370:Osteoarthritis, Knee / Q000503:physiopathology*