If you’ve ever read how this blog came about, you’ll know that osteoarthritis is a subject dear to my heart and right knee.
I described in agonising detail life before and after months of 850nm near-infrared light on my knee every day. Every day. Not just once a week, or twice a week, but every day.
Even then I knew enough about the effect of red and near infrared light on mitochondria to have worked out that mitochondria are like batteries and need a very regular recharge.
Mitochondria work best if they get daily boosts of energy courtesy of the response of their clever proteins that are able to absorb near infrared light and transform it into metabolic energy.
Maybe twice daily is even better, but definitely daily.
So when I saw a new journal article* looking at the effect of photobiomodulation on an exercise program for women with knee osteoarthritis, I was pretty pleased. It is already known that exercise improves osteoarthritis, so this study was assessing whether photobiomodulation with near infrared light would enhance that improvement.
The researchers divided the subjects with arthritic knees into two groups for the eight week intervention:
- The active group receiving a twice weekly exercise program followed immediately by an 808nm laser device shone into both sides of the knee.
- The placebo group received a twice weekly exercise program followed immediately by a pretend laser treatment to the knee.
The study is terrific in that is a randomised control trial, with high quality methods of assessing changes in pain, stiffness, knee function and movement over the eight weeks.
The study is depressing in that the photobiomodulation was only twice-weekly and only for eight weeks. The intervention was not often enough and not long enough. Even before I got to the end, it was clear what the results would be.
This study showed improvements in symptoms because of the exercise program, but no extra level of improvement from the use of twice-weekly photobiomodulation. Well, that was hardly a surprise.
My experience of people with arthritic conditions is that red/near infrared lights:
- need to be used daily,
- need to be used for longer than eight weeks
In defence of the researchers, they had a rider in their conclusion:
‘In this study, the exercise program improved pain, function and muscle strength of all the participants. However photobiomodulation, in the parameters used, did not optimize the effects of the exercise program in women with knee osteoarthritis.’
…‘in the parameters used’ is definitely the key phrase in this summary!
I’ve got some ideas why the researchers only did a twice-weekly photobiomodulation regime. I’ll put these ideas together in a new post.
Meanwhile, if you have osteoarthritis, then don’t let this sad study put you off. Photobiomodulation definitely does help, but it needs to be daily!
*Vassão PG, Silva BA, de Souza MC, Parisi JR, de Camargo MR, Renno ACM. Level of pain, muscle strength and posture: effects of PBM on an exercise program in women with knee osteoarthritis – a randomized controlled trial. Lasers in Medical Science. 2020. doi:10.1007/s10103-020-02989-1