Magnetic bands and bracelets for pain relief in OA
Date First Published:
December 1, 2006
Last Updated:
March 22, 2007
Report by:
Kathryn Moore & Michael Callaghan, Senior Physiotherapist and Research Physiotherapist (Manchester Royal Infirmary)
Search checked by:
Kathryn Moore, Manchester Royal Infirmary
Three-Part Question:
In [adults with OA] will [magnetic bands or bracelets] improve [symptoms and increase function]
Clinical Scenario:
A 60 year old female patient has treatment for widespread generalised OA. Her friend peruses the shopping channel and wants to buy a magnetic bracelet as a gift. Your patient wonders if this is a waste of money or may help her pain. You investigate further.
Search Strategy:
MEDLINE 1966-09/06, CINHAL 1982-090/06, AMED 1985-09/06, SPORTDiscus 1830-09/06, EMBASE 1996-09/06, via the OVID interface. In addition the Cochrane database and PEDro database were also searched.
Search Details:
(magnetic therapy.mp OR magnets) AND (osteoarthritis OR OA OR arthritis OR arthropathy OR arthrosis) LIMIT to human AND English language.
Outcome:
1 systematic review had a paragraph on magnets. 3 RCTs were also found that fulfilled the three part question.
Relevant Paper(s):
| Study Title | Patient Group | Study type (level of evidence) | Outcomes | Key results | Study Weaknesses |
|---|---|---|---|---|---|
| Effects of static magnets on chronic knee pain and physical function: a double blind study Hinman, M.R., Ford, J., Heyl, H. 2002 USA | n=43 Chroninc pain in 1 or both knee joints due to degenerative changes. Magnetic pad around knee |
Double-blind randomised controlled clinical trial | WOMAC | Improvement in pain and physical function in subjects wearing magnets over placebo. | Only 2 weeks long. n=43 Used uni-polar magnets (? does this have and effect over bi-polar) Blinding threatened. |
| 15m Walk | Slight improvement in gait speed but not statistically significant. | ||||
| Double-blind placebo-controlled trail of static magnets for the treatment of osteoarthritis of the knee: results of a pilot study Wolsko, P.M., Eisenberg, D.M., Simon, L.S., Davis R.B., Walleczek, J., Mayo-tSmith, M., Kaptchuk, T. 2004 USA | n = 29 Idiopathic or post traumatic OA Magnets in knee sleeve Group A = High strength magnets (active) Group B = Placebo magnets (placebo) |
Randomised double blind placebo controlled pilot study | WOMAC | Increase wrap wearing time > median time/day in active and placebo group = improvement in all WOMAC subscales @ 6/52 than wearing < median time /day. | Pilot: n = 29 Decreased placebo effect due to small sample size. |
| Change in 50m walk time | Superior results at 4 hours but not significant. No difference at 1 or 6 weeks | ||||
| VAS | Superior results at 4 hours but not significant. No difference at 1 or 6 weeks | ||||
| Global Ax of change | Superior results at 4 hours but not significant. No difference at 1 or 6 weeks | ||||
| Randomised controlled trail of magnetic bracelets for relieving pain in osteoarthritis of the hip and knee. Harlow, T., Greaves, C., White, A., Brown, L., Hart A., Ernst, E. 2004 UK | n = 194 OA hip or knee Bracelets worn on ventral wrist Group A = Standard magnets Group B = Weak magnetst Group C = Non-magnetic steel washers |
Randomised placebo controlled trial | WOMAC A | @ 12/52 standard magnet group = greater pain reduction, than placebo but not different from weak magnet group. | Blinding threatened Manufacturing error = wide variability in strength of placebo, some = same strength as standard. Can not be certain whether data shows specific effect of magnets, a placebo effect or both. Sample patients = predominately white with severe OA (WOMAC greater than or equal to 8) |
| WOMAC B | No difference between groups. | ||||
| WOMAC C | @ 12/52 standard magnet group = improvement in functioning, than placebo but not different from weak magnet group. | ||||
| VAS | Significant mean difference between standard magnets and placebo. | ||||
| Perceived monetary value of the bracelet | Participants estimate of thetmonetary worth did not differ significantly. | ||||
| Complementary or alternative therapies for osteoarthritis Ernst, E. 2005 UK | x1 Cochrane Review x3 RCT +1 other |
Review | Pain | Improved on motion in those who had magnet therapy over placebo | x1 Cochrane and x2 studies looked at pulsed magnetic fields not static magnets |
| Cochrane review | no definitive evidence of magnet efficacy | ||||
| Beneficial effects | x1 study | ||||
| Non beneficial | x2 studies |
Author Commentary:
- Differing results due to different type and strength of magnets used and length of treatment time.
- Small sample sizes.
- Difficulty maintaining blinding.
- Studies that showed no effect on pain generally used weaker magnets (19-50mtesla)
- Small sample sizes.
- Difficulty maintaining blinding.
- Studies that showed no effect on pain generally used weaker magnets (19-50mtesla)
Bottom Line:
There is some contradictory evidence that magnetic bracelets maybe beneficial in relieving symptoms of OA Knee/Hip
References:
- Hinman, M.R., Ford, J., Heyl, H.. Effects of static magnets on chronic knee pain and physical function: a double blind study
- Wolsko, P.M., Eisenberg, D.M., Simon, L.S., Davis R.B., Walleczek, J., Mayo-tSmith, M., Kaptchuk, T.. Double-blind placebo-controlled trail of static magnets for the treatment of osteoarthritis of the knee: results of a pilot study
- Harlow, T., Greaves, C., White, A., Brown, L., Hart A., Ernst, E.. Randomised controlled trail of magnetic bracelets for relieving pain in osteoarthritis of the hip and knee.
- Ernst, E.. Complementary or alternative therapies for osteoarthritis