title: Short-term effects of 890-nanometer radiation on pain, physical activity, and postural stability in patients with knee osteoarthritis: a double-blind, randomized, placebo-controlled study.
abstract: OBJECTIVE
  To investigate the effects of short-term light therapy with 890-nm radiation on pain, physical activity, and postural stability in patients with knee osteoarthritis (OA).
  
  
  METHODS
  A double-blind, randomized, placebo-controlled study.
  
  
  METHODS
  Rehabilitation clinic.
  
  
  METHODS
  Women (n=62) and men (n=10) with a mean age of 61.2 years (range, 40-88y). All patients fulfilled the combined clinical and radiographic criteria for knee OA as established by the American College of Rheumatology, and all had obtained a Kellgren-Lawrence score of 2 or more.
  
  
  METHODS
  Participants received 6 sessions, lasting 40 minutes each, of active or placebo radiation treatment over the knee joints for 2 weeks (wavelength, 890nm; radiant power output, 6.24W; power density, 34.7mW/cm(2) for 40 minutes; total energy, 41.6J/cm(2) per knee per session).
  
  
  METHODS
  Participants were assessed weekly over 4 weeks using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) for pain, stiffness, and physical function. Physical activity (timed stair climbing, 10-m fast-speed walking, and chair-rising time) and postural stability (using the postural stability evaluation system) were also assessed. The pain score on WOMAC was the primary outcome variable. Data were analyzed by repeated-measures analysis of covariance.
  
  
  RESULTS
  Compared with baseline, no significant improvement was observed between groups for pain (P=.546), stiffness (P=.573), or physical function (P=.904). No significant improvement was noted for physical activity including the 10-m fast-speed walking time (P=.284), stair-climbing time (P=.202), stair-descending time (P=.468), chair-rising time (P=.499), or postural stability (P=.986) at the 4 follow-up assessments. Follow-up assessments were conducted after 1 week of treatment (thus, after 3 treatments); after 2 weeks of treatment (thus, after 6 treatments); and 1 and 2 weeks, respectively, after treatment was terminated. Although we found a significant time effect for the 10-m fast-speed walking time (P<.001) in the 2 groups, and a significant group effect in the improvement of stair-climbing time in the treatment group (P=.032), the group × time interaction effects were not significant.
  
  
  CONCLUSIONS
  Short-term 890-nm radiation therapy for patients with knee OA provided no beneficial effect in improving pain, physical activity, and postural stability.
authors.affiliation: Department of Physical Medicine and Rehabilitation, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan; Taipei Medical University, Taipei, Taiwan. M001052@ms.skh.org.tw
authors.forename: Ru-Lan
authors.initials: RL
authors.lastname: Hsieh
authors.forename: Min-Tzu
authors.initials: MT
authors.lastname: Lo
authors.forename: Wei-Cheng
authors.initials: WC
authors.lastname: Liao
authors.forename: Wen-Chung
authors.initials: WC
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018771:Arthralgia / Q000209:etiology / Q000532:radiotherapy*; D016009:Chi-Square Distribution; D004311:Double-Blind Method; D005080:Exercise Test; D005260:Female; D006801:Humans; D007259:Infrared Rays / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D020370:Osteoarthritis, Knee / Q000150:complications / Q000503:physiopathology / Q000532:radiotherapy*; D004856:Postural Balance