Red Light Therapy for Lower Back Pain: Scientific Evidence

3 groups of 20 people with chronic non-specific low back pain, aged 30 to 60, took part in a 2022 randomized controlled trial testing photobiomodulation (PBM) combined with deep water running. The 60 participants included 47 women and 13 men, with one group receiving active PBM plus pool exercise, one receiving placebo PBM plus the same exercise, and one receiving PBM only with no exercise, using 660 and 850 nm light applied to 4 points on the lower back for 4 weeks. The combined active PBM and exercise group was associated with improvements in pain, disability, and walking test scores, along with changes in cortisol and creatine kinase.

Drug therapy alone and laser therapy combined with drug therapy were compared for acute low back pain in a 2021 randomized, placebo-controlled study of 65 patients. Group 1, with 20 patients, received only non-steroidal anti-inflammatory drugs (NSAIDs), while group 2, with 15 patients, received low-level laser therapy (LLLT) at 810 nm with a fluence of 3 to 6 J per cm2 and a maximum output of 100 mW, with pain scores tracked at baseline and weeks 1 through 4. Researchers found that combining laser therapy with drug therapy was associated with greater relief of pain and disability than drug therapy alone, though they described the supporting evidence as still inadequate.

Active photobiomodulation therapy (PBMT) and placebo PBMT were compared in 18 patients with chronic non-specific low back pain in a 2021 randomized, triple-blinded, placebo-controlled trial. A single session was applied using 640, 875, and 905 nm light across 9 sites on the low back for 3 minutes each, at doses of 3.0, 3.07, and 3.5 J per cm2, with serum prostaglandin E levels measured as the primary outcome. Researchers found that PBMT was associated with a reduction in this inflammatory marker compared with placebo, suggesting it may help modulate inflammation in this condition.

60 people with chronic non-specific low back pain were divided into 3 groups of 20 in a 2020 observational study comparing low-level laser therapy (LLLT), high-intensity laser therapy (HILT), and a control group receiving no laser therapy. Participants in the LLLT and HILT groups completed a 12-week program using lasers at 850 and 1064 nm with doses reported as 50 and 150 J per cm2, while researchers measured pain, disability, lumbar range of motion, and quality of life. Both the LLLT and HILT groups were reported to have significant reductions in pain and disability and improvements in lumbar mobility and quality of life, with no clear difference between the 2 treatments.

A prospective, single-center trial published in 2020 evaluated the effect of LED photobiomodulation therapy on non-specific chronic low back pain. The trial randomized 148 patients into 2 groups, with the intervention group receiving LED therapy to the lumbar area using 630 and 850 nm wavelengths at irradiances of 0.008 and 0.014 W per cm2 and doses of 5.7, 13.4, and 19.1 J per cm2, 3 times weekly for 2 weeks, while the sham group received placebo therapy on the same schedule. Researchers tracked pain, lumbar range of motion, chair rising time, fatigue, fear avoidance beliefs, and disability from baseline through 6 months, and reported that the LED intervention was effective, though specific outcome data were not provided.

3 treatment combinations were tested for chronic low back pain in a 2020 pilot randomized controlled trial, with 57 adults enrolled and 49 completing the study. The group receiving Mulligan sustained natural apophyseal glides (SNAGs) plus low-level laser therapy (LLLT) plus electrotherapy received the laser at 600 to 1000 nm and 27 J per cm2 for 10 minutes per session, 3 times weekly for 4 weeks, while comparison groups received SNAGs plus electrotherapy or electrotherapy alone. Researchers found that adding LLLT to SNAGs produced greater gains in pain, function, and range of motion than either comparison group.

40 adults aged 20 to 70 with low back pain took part in a randomized controlled trial published in 2020, comparing low-level laser therapy (LLLT) with a sham laser, both alongside naproxen. The true laser group received 12 sessions of an 808 nm infrared laser at 160 mW and 0.16 J per cm2 applied to the lumbar spine, paravertebral points, and pain-related acupuncture points, while the control group received 12 sessions with the same device turned off. At 3 months, researchers found that improvements in pain, functional status, and spinal range of motion that appeared in both groups at 1 month persisted only in the group receiving true laser, with spinal tenderness resolving in 89.47 percent of the laser group compared with 73.33 percent of the sham group.

36 patients with chronic nonspecific low back pain were enrolled, with 35 completing a 2020 randomized controlled trial after being randomly assigned to a pulsed Nd:YAG laser group of 18 or a sham group of 17. The active group received 1064 nm light at 6 to 12 W, with fluence ranging from 6 to 150 J/cm² and sessions lasting 30 to 75 seconds, delivered 3 times weekly to the lumbar region for 42 days. The study reported significant improvements in disability scores, pain scores, and lumbar range of motion in the Nd:YAG group, while the sham group showed no significant changes over the same period.

A relative pain reduction of 91.2 percent was reported in the pulsed laser group, the largest gain among 4 groups in a 2019 randomized controlled clinical trial on chronic non-specific low back pain in 100 women. The pulsed low-level laser therapy (LLLT) group, made up of 26 participants, received 904 nm light at an irradiance of 1 W per cm2 and a dose of 3 J per cm2 applied to the low back, while the other groups received pulsed ultrasound, continuous ultrasound, or no active treatment. All 3 active treatments were associated with reduced pain and improved functional disability compared with control, though the pulsed ultrasound group showed the largest gain in function at 83.3 percent.

A 2019 randomized trial compared the effects of laser photobiomodulation therapy (LPBMT) and ultrasound therapy on chronic non-specific low back pain in 45 patients aged 30 to 40. 3 groups of 15 each received either LPBMt combined with exercise, ultrasound therapy combined with exercise, or exercise alone, with both active treatments applied twice weekly over 8 weeks at 808 nm, 113.6 mW/cm², and 17.05 J/cm². The study reported significant improvements in pain, disability, and functional performance in both treatment groups, but only the LPBMt group was associated with significant improvement in lumbar range of motion, and LPBMt outperformed ultrasound therapy across every measure.

An observational study published in 2018 looked at whether photobiomodulation (PBM) added to physical therapy could help with depression symptoms in patients with low back pain. The study included 10 participants, with 5 outpatients receiving physical therapy over 5 weeks plus PBM to the back and thighs during the final 3 sessions, compared with 5 retrospectively matched controls who received physical therapy alone, using 850 and 660 nm light at an irradiance of 100 mW per cm2. They found that baseline scores were similar between groups except for higher functional status in the PBM group, and they described a preliminary antidepressant effect that may be associated with PBM in these patients.

330 patients with chronic non-specific low back pain were divided into three equal groups in a 2018 randomized controlled trial, comparing spinal manipulation plus low-level laser therapy (LLLT) and exercise, LLLT plus exercise alone, and a control group. Patients were treated for 4 weeks using an 830 nm laser at doses of 4 and 28 J per cm2, with outcomes measured at baseline, 4 weeks, 6 months, and 12 months. At the 12-month follow-up, researchers found that patients in the spinal manipulation plus LLLT plus exercise group showed significantly greater improvement in pain, range of motion, disability, depression, and quality of life compared with the other two groups.

A double-blinded trial published in 2017 compared two different low-level laser therapy (LLLT) regimens combined with hot pack treatment for chronic low back pain. The trial randomized 49 patients into 2 groups, with group 1, made up of 20 patients, receiving an 850 nm Gallium Aluminum Arsenide laser, and group 2, made up of 29 patients, receiving a combined plaque laser using 650 nm Helium Neon and 785 and 980 nm Gallium Aluminum Arsenide light, both groups completing 15 sessions. Both groups showed significant improvements in pain, global assessments, lumbar range of motion, and disability scores, with the combined plaque laser group showing greater gains in lateral flexion and disability, though pain reduction did not differ between the two laser types.

Short-term pain reduction was reported in a 2016 meta-analysis of low-level laser therapy (LLLT) for chronic non-specific low back pain. The review combined 15 randomized, sham-controlled trials with 1,039 participants, using wavelengths ranging from 680 to 1064 nm, with the benefit appearing mainly in trials delivering at least 3 joules per point and in people with shorter pain duration. It was concluded that LLLT was associated with greater odds of overall improvement compared with sham treatment, and they described the evidence as moderate quality, supporting a clinically important short-term benefit under those conditions.

In a 2016 randomized controlled trial, laser treatment, lidocaine injection, and radiofrequency neuromodulation were compared for chronic low back pain in 28 patients. The laser group received a single treatment using a continuous wave diode at 808 nm and 100 mW, delivered through an optical fiber to the second lumbar spinal nerve for 84 seconds. Researchers found that laser and lidocaine produced immediate pain reductions of at least 50 percent in all treated patients, while 10 of 11 radiofrequency patients reported similar relief, and at 1 month, laser patients showed the highest continued relief at 7 of 10 compared with 2 of 7 for lidocaine and 3 of 11 for radiofrequency.

A 2015 meta-analysis evaluated the effect of low-level laser therapy (LLLT) on nonspecific chronic low back pain. Researchers pooled 7 randomized controlled trials with 394 patients, using wavelengths of 810, 890, 904, 980, and 1060 nm, comparing LLLT against placebo treatment. Patients receiving LLLT were reported to have lower pain scores than those receiving placebo, although disability and spinal range of motion did not show a clear difference between groups.

Patients reported very or fairly satisfied outcomes after a 2015 clinical trial tested tri-length laser therapy combined with tecar therapy for low back pain in 66 adults, with or without leg pain. The combined treatment used 650, 810, 980, and 1064 nm wavelengths at 1 mW to 12 W, with a total energy of 500 J applied for 20 minutes per session, 3 times weekly for 10 sessions over 10 days, to the lumbar spine and lower back. Pain scores on the visual analog scale dropped from an average of 8.1 to 2.63, and disability scores on the Oswestry Disability Scale fell from 53 to 23.5, 8 weeks after treatment.

Both monochromatic infrared photo energy (MIPE) and low-level laser therapy (LLLT) produced equally significant improvements in chronic low back pain when paired with exercise according to a 2015 observational study with 76 enrolled patients, of whom 70 completed the program. The MIPE group of 35 received 850 and 890 nm light at 10 mW/cm² and 48 to 62.4 J/cm², while the LLLT group of 35 followed the same exercise schedule with active laser therapy, with both groups treated twice weekly over 6 weeks. Pain levels, daily function, and back movement improved significantly in each group, but the study found no statistical difference between MIPE and LLLT on any measure.

49 out of 50 patients with treatment-resistant discogenic back pain showed significant improvement after low-level laser therapy (LLLT) in a 2015 observational study with a mean 5-year follow-up. All participants had previously failed pain medication and at least 3 months of conventional physical therapy before receiving 810 nm light at 20 mW/cm² and 5.4 J per point to the lumbar spine, 3 times weekly over 12 weeks. Daily function scores dropped from a mean of 50% disability to 10% at 12 weeks, and the study reported these improvements were maintained at both 1-year and 5-year follow-up assessments.

Spine mobility improved substantially after 60 patients with chronic low back pain from lumbar disc herniation (slipped disc) received low-level laser therapy in a 2014 clinical trial. They received 820 nm laser light at 400 mW, with doses of 6 to 12 J/cm² applied to the lumbar spine, and were assessed before and after rehabilitation using a modified Laitinen questionnaire, a visual analog scale, Schober's test, and the fingertip-to-floor test. The evaluation indicated a slight reduction in pain intensity, frequency, and painkiller use, alongside gains in flexion and extension.

The Perth-based randomized controlled trial published in 2014 tested whether laser dose mattered for chronic non-specific low back pain in 144 adults treated with laser acupuncture (LA). Three groups, sham, low dose, and high dose, received an 840 nm diode laser at 100 mW/cm² and 20 mW, applying 0, 0.2, or 0.8 J per point for 10 to 40 seconds, once weekly over 56 days to acupuncture points on the lower back. All 3 groups showed significant reductions in pain and disability by 6 weeks, with no significant difference detected between doses, suggesting other factors may have driven the improvement.

Published in 2014, this randomized trial compared high-intensity laser therapy (HILT) plus exercise, placebo laser plus exercise, and HILT alone in 72 male patients with chronic low back pain, average age 32.81 years. Active treatment used 1064 nm light at 3000 W and 0.51 to 1.78 J/cm², delivered for 15 minutes, 12 times weekly over 28 days to the lower back and surrounding muscles. Lumbar range of motion increased and pain and disability scores fell in all 3 groups at 4 weeks, with some benefits remaining at 12 weeks, and HILT combined with exercise was reported as the most effective of the 3 approaches.

Exercise helps chronic low back pain, but a 2014 randomized controlled trial with 100 patients, average age of 60 years, found that pairing diode laser therapy with exercise produced a greater reduction in pain than exercise alone in patients with chronic low back pain. The 50 patients in the laser group received 980 nm light at 20 W and 37.5 J/cm² applied to the lower back for 60 seconds, 3 times weekly over 3 weeks, while the other 50 used a placebo laser during the same exercise program. The laser group averaged a 3.96-point drop in pain scores versus 2.23 points in the exercise-only group, a difference the study identified as statistically significant.

Published in 2012, this randomized controlled trial tested 3 energy doses of low-level laser therapy (LLLT) to determine whether they produced different outcomes in 66 patients with acute low back pain and radiculopathy. 3 groups of 22 each received 10 sessions of LLLT at 904 nm, 25 mW, and 3,000 Hz, 5 times weekly over 14 days, at energy doses of 0.1 J, 1 J, or 4 J per point. All 3 doses were associated with significant reductions in back and leg pain, but the study reported that the 4 J per point dose produced greater improvements in daily movement and lumbar mobility. No side effects were reported in any group.

8 out of 9 patients with sacroiliac joint pain showed significant pain improvement after low-level laser therapy (LLLT) in a 2011 observational study. The 9 participants, 4 men and 5 women with an average age of 50.4 years, received an 830 nm continuous wave diode laser at 1 W, applying 20-21 J/cm² for 30 seconds per point to bilateral tender points around the sacroiliac joint, 2 times weekly for 35 days. Researchers also found that 6 patients showed significantly increased trunk mobility, and the study described LLLT as potentially effective for sacroiliac pain.

30 patients with low back pain were randomly assigned to high-intensity laser therapy (HILT) or ultrasound therapy in a 2011 randomized controlled trial conducted at a university hospital in Italy. The HILT group received 1064 nm light at 0.76 J/cm² and 6 W, with a 10-minute session totaling 2600 J, delivered 5 times weekly for 21 days, compared with the same schedule of ultrasound sessions. The trial reported that the HILT group showed a greater decrease in pain on the visual analog scale and greater improvement in disability scores than the ultrasound group, with no baseline differences between groups before treatment.

A 2010 clinical trial looked at whether low-level laser therapy (LLLT) could relieve low back pain better than ultrasound or vacuum therapy with electrical stimulation in 94 patients. The 35 patients in the laser group received 10 sessions at 808 nm, 510 mW/cm², and 12 J/cm², 10 times weekly, while the remaining patients were split between ultrasound therapy and vacuum therapy with electrical stimulation. The study reported LLLT was associated with a significant reduction in pain intensity and reduced use of pain medication compared to the other two treatments.

According to a 2010 randomized, double-blind, placebo-controlled trial with 546 patients, low-level laser therapy (LLLT) used alongside pain medication produced better results than medication alone for acute low back pain with radiculopathy. The trial applied 904 nm light at 20 mW/cm² and 3 J/cm² to the affected spine area for 2.5 minutes, 5 times weekly over 15 sessions, and compared 3 groups receiving pain medication plus active LLLT, pain medication only, or pain medication plus a placebo device. Researchers found significant improvements in pain, back movement, daily function, and quality of life across all groups, with the largest gains in the LLLT group.

A randomized controlled trial in 2007 enrolled 61 patients with chronic low back pain lasting at least 12 weeks. The trial applied 810 nm light at 27 J/cm² to the paravertebral region for 20 minutes, twice weekly for 42 days, and compared low-level laser therapy (LLLT) alone, LLLT plus exercise, and placebo laser plus exercise. The study reported that LLLT combined with exercise may help reduce pain, improve lumbar motion, and lower disability scores more than exercise alone at 12 weeks.

Patients with subacute low back pain and radiculopathy were split into 2 groups of 30 for a 2006 single blind randomized controlled trial comparing low-level laser therapy (LLLT) combined with other treatments to medication alone. One group received LLLT at 904 nm and 2 J per point, totaling 12 J, delivered over 15 sessions across 21 days, together with TENS, exercise, and meloxicam, while the other group received only meloxicam. The study found the LLLT combination produced better outcomes for pain, disability, and quality of life than meloxicam alone.

Pain scores fell from 6.9 to 3 out of 10 in patients using an active infrared therapy (IRT) device, according to a 2006 randomized controlled trial in 40 patients with chronic low back pain lasting more than 6 years. The 21 patients in the active group and 18 in the placebo group wore similar waistband units over the lower back, with active devices delivering 800 to 1200 nm energy over 7 sessions weekly for 49 days, and pain was rated weekly using the numerical rating scale. The placebo group's scores fell only from 7.4 to 6 out of 10 over the same period, and researchers concluded the device may help reduce chronic low back pain, with no adverse effects reported in either group.

A 1990 observational study focused on a group of 82 patients with low back pain who were treated using infrared laser therapy (IRLT) from a semiconductor laser, applying wavelengths between 780 and 1400 nm to the lower back. Researchers used a pain questionnaire to evaluate pain intensity, pain frequency, analgesic use, and motor activity before and after treatment. It was concluded that IRLT had a favorable effect on pain in these patients.

A meta-analysis published in 2008 pooled 7 trials examining low-level laser therapy (LLLT) for non-specific low back pain, applying wavelengths between 632 and 904 nm and at 1060 nm to the lumbar spine in sessions ranging from 1 to 20 times weekly. Among the findings, 3 small studies covering 168 people found a small but statistically significant pain relief from LLLT compared with sham therapy. 1 study of 56 people found LLLT reduced disability more than sham in the short term. Other studies totaling 192 people found LLLT plus exercise or LLLT alone showed no clear advantage over exercise with or without sham. 2 trials covering 151 people separately found a lower relapse rate in the LLLT group at 6 months. While there were no side effects reported, the authors concluded the overall evidence was too mixed to draw firm conclusions.

Six randomized controlled trials with 318 total participants were pooled in a 2007 meta-analysis examining low-level laser therapy (LLLT) for non-specific low back pain, using wavelengths between 632 and 904 nm and at 1060 nm with doses ranging from 0.1 to 48.8 J. Researchers found some evidence of pain relief with LLLT compared with sham treatment at short-term and intermediate-term follow-up, though no difference was seen in pain-related disability and there was not enough evidence to judge effects on lumbar range of motion. Two of the trials reported a lower relapse rate in the LLLT group at 6 months, but the authors concluded the overall evidence was not sufficient to draw firm conclusions. No side effects were reported.

Researchers in 2003 studied the effect of low power laser therapy (LPLT) on chronic low back pain in a randomized controlled trial with 75 patients. The trial split participants into 3 groups of 25, comparing laser plus exercise, laser alone, and exercise alone, using 780 to 830 nm light at 1 J/cm² for 30 minutes, 5 times weekly over 28 days, applied to areas including the lower back, hamstrings, and gluteal region. Significant gains in pain and disability scores were reported across all 3 groups, with lateral flexion the only measure that did not improve.

63 adults aged 18 to 70 with non-radiating low back pain took part in a 1999 randomized, controlled trial testing low-intensity laser therapy. Treated subjects received irradiation at 1060 nm and 542 mW/cm², applying doses of 1 to 4 J/cm² to 8 points along the lumbosacral spine, 3 times weekly for 28 days, while the control group underwent the same procedure with an inactive laser. Improvements in pain perception and function were strongest around the midpoint and end of treatment, though the study found these gains tended to fade by the 1-month follow-up, with no difference in lumbar mobility between groups.

Researchers in 2024 conducted a randomized, double-blind, sham-controlled trial to see whether photobiomodulation therapy (PBMT) could boost the effects of mat Pilates for chronic non-specific low back pain. 38 adults were split into 2 groups, both completing an 8-week Pilates program, with one group also receiving active PBMT at 660 and 850 nm and a dose of 19.2 J per cm2 to the lumbar muscles for 10 minutes before and after each session, while the other received sham PBMT. Pain intensity, disability, and pain catastrophizing improved with Pilates alone. PBMT added nothing measurable, and postural balance remained unchanged in both groups.

At an outpatient physical therapy clinic in Brazil, researchers ran a 2021 randomized, placebo-controlled trial testing photobiomodulation therapy (PBMT) for chronic non-specific low back pain. 148 patients were split into 2 groups of 74, receiving either active PBMT or placebo, with 12 sessions over 4 weeks using 640, 875, and 905 nm wavelengths at a total energy of 220 J per treatment, and both groups also received an educational booklet. At 4 weeks, researchers found no clinically important difference between groups in pain intensity or disability, and reported no adverse events in either group.

PBMT was compared with sham treatment, exercise, ultrasound, and Tecar therapy for non-specific low back pain in a 2020 meta-analysis of 12 randomized controlled trials. The review included 1,046 participants and examined wavelengths ranging from 650 to 1064 nm, at an irradiance of 1,000 mW per cm2 and a dose of 0.42 J per cm2. Researchers found that PBMT did not produce a clinically important reduction in pain or disability compared with sham, and the comparisons with ultrasound and Tecar therapy were also reported as imprecise.

According to a 2019 placebo-controlled trial, all 68 participants with chronic nonspecific low back pain completed the same standard stabilization exercises regardless of group assignment. Patients were randomized into 4 groups receiving high intensity laser therapy (HILT) at 1064 nm and 60 J per cm2 for 10 minutes, low level laser therapy (LLLT) at 785 nm and 8 J per cm2 for 8 minutes, or matching sham treatments, with postural stability assessed before treatment, after 3 weeks, and at 1 and 3 month follow-ups. The trial reported some short-term improvement in postural sway, but found no statistically significant difference between active laser therapy and sham.

4 treatment groups, including high intensity laser therapy (HILT), low level laser therapy (LLLT), and placebo irradiation, were compared for lumbar disc degenerative changes in a 2018 randomized controlled trial. 68 participants took part, with lasers delivered at wavelengths of 1064, 785, and 670 nm and doses of 8 and 60 J per cm2, and outcomes tracked across short and long-term follow-ups. While progress was seen across all groups, researchers reported no statistically significant differences between real and placebo laser, suggesting these methods may not offer a clear benefit for this condition.

A randomized, double-blind, placebo-controlled trial published in 2010 evaluated the effect of laser acupuncture on chronic back pain in 111 male and female patients aged 30 to 77 with pain lasting more than 6 months. One group received active laser acupuncture at 680 and 785 nm with an irradiance of 1,000 to 5,000 mW/cm² and power of 50 to 150 mW for 15 minutes 10 times weekly, while the other received a placebo device, with the primary goal being a 50% reduction in pain scores at 3 months. Pain scores improved in both groups, but laser acupuncture was not associated with any advantage over the placebo device.

Chronic non-specific low back pain improved in both groups of a 2009 double blind randomized controlled trial testing laser acupuncture (LA) against a sham laser in 100 adults. The active group received an 830 nm infrared laser at 10 mW, delivering 0.2 J per point to acupuncture points over 5 to 10 sessions in a general practice setting, with the visual analog scale and the Oswestry Disability Index used to assess pain and disability at 6 weeks and 6 months. No significant difference emerged between the laser and sham groups, leading researchers to suggest the improvement may have come from factors other than the laser.

Researchers in 1990 studied the effect of low-energy laser therapy on chronic low back pain in a randomized double-blind trial with 20 patients. 10 patients received low-energy laser treatment at 780-830 nm with a dose of 0.1 J/cm², and 10 received a placebo laser, with both groups following the same active exercise program. Researchers measured pain, daily function scores, and physical tests including spine movement and muscle strength for 1 month, before and after treatment. The study reported significant improvements in both groups, but low-energy laser therapy combined with exercise showed no advantage over exercise alone.