title: Energy expenditure during cane-assisted gait in patients with knee osteoarthritis.
abstract: OBJECTIVE
  To compare the energy expenditure in patients with unilateral knee osteoarthritis while walking with canes of different lengths.
  
  
  METHODS
  A quasi-experimental study (single-group) was carried out on thirty patients with unilateral knee osteoarthritis. An adjustable aluminum cane was used, and three different cane lengths were determined for each subject: C1--length from the floor to the greater trochanter; C2--length from the floor to the distal wrist crease; and C3--length obtained by the formula: height x 0.45 + 0.87 m. Resting and walking heart rates were measured with a Polar hear rate meter. Walking speed was calculated by the time required for the patient to walk 10 m. Gait energy cost was estimated using the physiological cost index, and results were compared.
  
  
  RESULTS
  The sample consisted of 25 women and five men (average age of 68 years). Statistically significant differences in physiological cost index measurements were observed between unassisted walking and assisted walking with a cane of any length (p<0.001), as well as between walking with a C2-length cane and unassisted walking, and walking with a C1-length cane and walking with a C3-length cane (p=0.001; p = 0.037; p=0.001; respectively).
  
  
  CONCLUSIONS
  These data demonstrate that small alterations in the length of canes used for weight-bearing ambulation in patients with unilateral knee osteoarthritis increase the energy expenditure measured by the physiological cost index during walking. Further studies are needed for a more precise quantification of the increase in energy expenditure during cane-assisted gait and an assessment of the effectiveness of cane use in relieving pain and improving function in patients with knee osteoarthritis.
authors.affiliation: Rheumatology Discipline, Universidade Federal de São Paulo, São Paulo, SP, Brasil.
authors.forename: Anamaria
authors.initials: A
authors.lastname: Jones
authors.forename: Ana Claudia Monteiro
authors.initials: AC
authors.lastname: Alves
authors.forename: Leda Magalhães
authors.initials: LM
authors.lastname: de Oliveira
authors.forename: Marcelo
authors.initials: M
authors.lastname: Saad
authors.forename: Jamil
authors.initials: J
authors.lastname: Natour
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002183:Canes; D004734:Energy Metabolism / Q000502:physiology*; D005260:Female; D005684:Gait / Q000502:physiology*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000503:physiopathology*; D016138:Walking / Q000502:physiology*; D016474:Weight-Bearing