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

Ru Lan Hsieh, Min Tzu Lo, Wei Cheng Liao, Wen Chung Lee

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13 Citations (Scopus)


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). Design: A double-blind, randomized, placebo-controlled study. Setting: Rehabilitation clinic. Participants: 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. Interventions: 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). Main Outcome Measures: 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

Original languageEnglish
Pages (from-to)757-764
Number of pages8
JournalArchives of Physical Medicine and Rehabilitation
Issue number5
Publication statusPublished - May 2012



  • Osteoarthritis, knee
  • Pain
  • Physical activity
  • Radiation
  • Rehabilitation
  • Stability

ASJC Scopus subject areas

  • Rehabilitation
  • Physical Therapy, Sports Therapy and Rehabilitation

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