Red Light Therapy for Plantar Fasciitis: Scientific Evidence

Researchers in 2021 ran a randomized controlled trial to compare low-level laser therapy (LLLT) and extracorporeal shock wave therapy (ESWT) for calcaneal spurs in 62 patients, including 14 men and 48 women averaging 47.6 years old. Of these, 31 received a 904 nm laser at 3000 Hz and 8 J per square centimeter to the heel and plantar fascia for 5 minutes, 3 times a week over 21 days, and the other 31 received ESWT, with both groups also completing stretching exercises and cold pack treatment. Researchers found that both treatments significantly reduced pain and improved function, though ESWT showed a slightly greater improvement in function scores, suggesting LLLT may work about as well as ESWT for calcaneal spurs.

While objective measures showed no difference between treatments, a 2020 trial found more participants rated high-intensity laser therapy (HILT) as effective than low-level laser therapy (LLLT) for plantar fasciitis. Conducted in Lithuania, the trial included about 102 participants, roughly 51 per group, who received 8 laser sessions over 3 weeks, with HILT delivered at 1064 nm and up to 120 J per square centimeter and LLLT at 785 nm and 4 J per square centimeter, both to the plantar fascia and heel, with outcomes assessed at baseline, 3 weeks, and 4 weeks. Pain, pressure pain threshold, and fascia thickness improved similarly in both groups, but significantly more participants rated HILT as over 50% effective than LLLT (73% versus 51%), suggesting HILT may be perceived as more effective even though objective results were comparable.

A total of 40 patients with spondyloarthritis and heel pain lasting at least 6 months took part in a 2020 randomized controlled trial comparing low-level laser therapy (LLLT) and extracorporeal shock wave therapy (ESWT) for plantar fasciitis. LLLT involved 14 sessions of an 830 nm Ga-Al-As infrared laser delivered to the plantar fascia at 50 mW, a fluence of 8 J per square centimeter, and a pulse frequency of 10 Hz, and ESWT involved just 3 sessions, with both treatments completed over 21 days and foot function, pain, quality of life, and plantar fascia thickness on MRI assessed before treatment and 1 month afterward. Both groups reported statistically significant improvement in foot function and pain after treatment, suggesting that LLLT may help relieve plantar fasciitis pain in patients with spondyloarthritis at the dose and schedule studied.

Across three separate measures, pain, foot function, and fascia thickness, a 2019 randomized trial found that low-level laser therapy (LLLT) worked about as well as extracorporeal shock wave therapy (ESWT) for plantar fasciitis. The trial enrolled 34 patients, 5 men and 29 women ranging from 18 to 65 years old, randomly assigned to LLLT at 685 nm and 30 mW with a fluence of 1 to 2 J per square centimeter for 2-minute sessions, given over 12 total treatments across 28 days, or to ESWT, with assessments before treatment, after treatment, and 1 month later. Both treatments produced significant improvement on all three measures compared with baseline, and neither treatment outperformed the other over time, suggesting LLLT may offer a comparable alternative to ESWT for plantar fasciitis.

A four-arm randomized, controlled trial in 2019 tested whether light-based photobiomodulation therapy (PBMT) could improve on extracorporeal shock wave therapy (ESWT) for plantar fasciitis, and found that only the sham group failed to significantly improve. 120 patients were split evenly into four groups of 30, ESWT, PBMT, combined ESWT and PBMT, and sham, with PBMT delivered at 670 to 950 nm and 2.8 J per square centimeter for 60 seconds a session, and results tracked at baseline, 3 weeks, and 12 weeks, though 12 of the 120 patients declined the 12 week follow-up, leaving 108 evaluated at that point. The combination group improved the most, ahead of ESWT alone and then PBMT alone, suggesting that combining light therapy with ESWT may offer the greatest benefit for plantar fasciitis.

A systematic review and meta-analysis published in 2019 evaluated whether low-level laser therapy (LLLT) could relieve pain from plantar fasciitis. The researchers pooled 6 randomized controlled trials found through database searches completed by March 2018, comparing LLLT against control treatment, with the included studies using laser wavelengths of 780 to 830 nm and energy doses ranging from 1 to 8.4 J, applied to areas around the heel and plantar fascia. The meta-analysis found that LLLT was associated with a significant reduction in heel pain on the visual analog scale right after treatment, with the improvement lasting up to 3 months, though no significant difference appeared on the Foot Function Index pain subscale.

Pain improved significantly in patients with plantar fasciitis treated with either low-level laser therapy (LLLT) or high-intensity laser therapy (HILT) in a 2018 randomized controlled trial, with 70 of the 75 originally enrolled completing treatment. Each 35-patient group was similar in age and sex, with the LLLT group including 8 men and 27 women averaging 48.65 years old and the HILT group including 7 men and 28 women averaging 48.73 years old, and both received 9 sessions over 3 weeks, three times a week, with LLLT delivered at 904 nm and 240 mW to the plantar fascia and HILT delivered at 1064 nm in two phases to the same area. The study reported that both groups improved significantly in pain, heel tenderness, and foot and ankle scores, with VAS pain scores falling from 8.87 to 2.75 in the HILT group compared with 8.35 to 5.56 in the LLLT group, suggesting HILT may be more effective than LLLT for plantar fasciitis.

In a 2018 randomized controlled trial of 66 patients with plantar fasciitis, 24 patients treated with low-level laser therapy (LLLT) reported lower pain scores than 25 patients treated with extracorporeal shock wave therapy (ESWT), with both groups also receiving usual care. Those in the LLLT group had an 830 to 850 nm laser applied to the plantar fascia at 70 mW, with fluence reaching up to 5.6 J per square centimeter across 10 sessions of 5 to 7 minutes over 21 days, and a third group of 17 patients stuck to usual care alone, with everyone also following a home exercise program and using orthotic support. Pain eased across all three groups by 3 months, but the improvement was greater with LLLT than with either ESWT or usual care alone, suggesting that combining LLLT with usual care may bring extra short-term relief for plantar fasciitis.

Patients treated with low-level laser therapy (LLLT) for plantar fasciitis in a 2018 randomized controlled trial showed a 13% improvement in foot function, well ahead of the 4% improvement among those who received usual care alone. The trial enrolled 49 adults averaging 46 years old, most of them women, putting 27 through 10 LLLT sessions over 3 weeks using an 850 nm gallium aluminum arsenide laser delivered to the plantar fascia at 100 mW, and assigning the other 22 to usual care alone, with both groups also following a home exercise program and using orthotic support. By 3 months, VAS pain scores had fallen from 6.13 to 1.72 in the LLLT group, a steeper drop than the decrease from 5.49 to 3.67 seen with usual care alone, suggesting that adding LLLT may bring extra pain relief beyond usual care by itself.

Comparing low-level laser therapy (LLLT), ultrasound therapy, and extracorporeal shock wave therapy (ESWT), a 2017 randomized controlled trial evaluated treatments for chronic plantar fasciitis using MRI. 60 patients were split into LLLT (17), ultrasound (17), and ESWT (20) groups, with LLLT delivered at 830 nm and 50 mW to the heel and plantar fascia for 15 sessions over 3 weeks, and outcomes tracked with MRI and clinical scores before and 1 month after treatment. All three treatments significantly reduced pain and fascial thickness, with no side effects reported, though ESWT outperformed ultrasound on function while LLLT didn't differ significantly from either, suggesting LLLT may work about as well as the other two options for plantar fasciitis.

Adults averaging 56.7 years old, most of them women, took part in a 2015 placebo-controlled randomized trial of low-level laser therapy (LLLT) for chronic plantar fasciitis. Conducted at multiple centers from 2011 to 2013, the trial enrolled 69 people with unilateral chronic plantar fasciitis, and the LLLT group received a 635 nm laser at 17 mW to the top of the foot and the heel, in 10 minute sessions, twice a week for 3 weeks, for 6 sessions total, and the other group received an identical placebo, with pain assessed before treatment and at weeks 1, 2, 3, 6, and 8. By the end of the trial, the LLLT group had a significantly larger drop in pain than the placebo group, 29.6 points versus 5.4 points, suggesting that LLLT may ease chronic plantar fasciitis pain, even though the two groups ended up with similar foot function scores.

30 patients with chronic plantar fasciitis saw their pain scores drop from 67.8 to 6.9 out of 100 over 12 months in a 2014 observational study of low-level laser therapy (LLLT). All 30 patients received LLLT at 635 nm and 17 mW to the dorsal foot and the myofascial and plantar aspects of the heel, in 10-minute sessions, twice a week for 3 weeks, for 6 sessions total, with follow-up at 2 weeks, 6 months, and 12 months after treatment. The study reported that mean Foot Function Index scores improved from 106.2 at baseline to 32.3 at 12 months, and the authors concluded that LLLT may be a promising treatment for chronic plantar fasciitis.

35 out of 44 feet treated with infrared rays showed lower pain scores at 6 months in a 2012 clinical trial of plantar fasciitis. Researchers added infrared ray therapy at 780 to 1400 nm to standard NSAID and Achilles tendon stretching care in 70 patients, and tracked pain with a visual analog scale at the start of treatment and again after 180 days. The infrared group's VAS scores dropped from 8.70 to 3.38, a larger improvement than the drop from 8.41 to 5.28 reported in the group receiving conservative care alone, suggesting infrared therapy may add benefit over conservative treatment by itself. The study also reported the therapy was safe and easy to use, with no patients experiencing worsened symptoms.

A randomized, double-blind, placebo-controlled trial published in 2010 evaluated the effect of low-level laser therapy (LLLT) on plantar fasciitis. A total of 30 adults, averaging 41 years old and including 6 women and 9 men in each group, enrolled, with 25 completing the study, and the plantar fascia was treated with a 904 nm laser at 80 to 160 mW per square centimeter for about 2.6 minutes per session, 18 times a week, over 42 days. The pain scores dropped significantly more after LLLT than after placebo treatment, suggesting the therapy may help reduce pain from plantar fasciitis, though ultrasound measurements showed no significant difference in fascia thickness between the two groups after treatment. All participants tolerated the treatment well, with no side effects or adverse reactions such as increased pain or skin irritation.

Across three separate outcome measures, a 2026 randomized, double-blind, sham-controlled trial found that high-intensity laser therapy (HILT) added no clinical benefit over sham treatment for plantar fasciitis. Conducted in Thailand, the trial enrolled 34 patients with plantar fasciitis, randomly assigned to receive either active HILT or an identical sham treatment using a 1064 nm laser at 12 W for about 4.17 minutes per session, delivering 120 J per square centimeter over a 25 square centimeter area, in 9 sessions over 3 weeks, with both groups also doing plantar fascia and Achilles tendon stretching exercises throughout. Both groups showed significant improvement in pain, plantar fascia thickness, and foot and ankle function compared with baseline, but found no significant difference between the HILT and sham groups on any of these measures, suggesting HILT may not add extra benefit beyond sham treatment combined with stretching for plantar fasciitis.

A 1998 randomized, double-blinded, placebo-controlled trial set out to test both the safety and the effectiveness of low-intensity laser therapy for plantar fasciitis. Over 4 weeks, 32 otherwise healthy adults with plantar fasciitis lasting more than a month received 3 sessions a week of either active or dummy infrared laser irradiation lasting 33 seconds each, delivered at 830 nm and 30 mW, while researchers tracked morning pain, pain on toe walking, tenderness, and orthotic use before treatment, partway through, right after, and again a month later. None of those measures differed significantly between the active and placebo groups at any point, suggesting the therapy may not add real benefit for plantar fasciitis at this dose and schedule. It did, however, prove well tolerated, with only minimal side effects reported.