Article

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<.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 x 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.
CI - Copyright (c) 2012 American Congress of Rehabilitation Medicine. Published by
Elsevier Inc. All rights reserved.

Langue : ANGLAIS