Updated
The laser therapy at our Clarksville practice uses the Summus Horizon Class IV Medical Laser. We use it as part of a plan for sore, stiff muscles and joints, alongside the other care we provide.
What the Horizon laser is for
The Horizon delivers light at four wavelengths that warms the tissue it's aimed at. Summus lists its uses as temporary relief of:
- minor muscle and joint pain
- muscle and joint stiffness
- minor arthritis pain
- muscle spasms
Summus also lists a temporary increase in local circulation and muscle relaxation. Those are the uses we put the Horizon to. The manufacturer's notice says the FDA hasn't cleared or approved its devices for any other clinical uses.
Where we use laser therapy
After we've examined you, we may add the laser to your plan for pain and stiffness in the:
- low back
- neck
- shoulder and rotator cuff area
- knee
- foot and plantar fascia
We also use it on muscles and joints strained by sports and overuse.
The laser is one part of a broader plan, used alongside the other care we provide.
We don't use the laser to treat diabetic neuropathy, trigeminal neuralgia, wounds, ulcers or burns, or for cosmetic skin treatment. If you have diabetes and also a muscle or joint complaint we treat, the laser may still be part of care for that pain once we've examined you. It isn't a treatment for the neuropathy itself.
What a laser session is like
Protective eyewear is required during treatment with a Class IV laser, because the beam can harm the eyes. The laser is delivered through a handpiece aimed at the area being treated, and nothing cuts or punctures the skin. What you're likely to notice is warmth, since warming the tissue is what the laser is designed to do.
Summus builds the Horizon with settings for skin tone, custom protocols saved for each patient, and a record of each patient's treatment history.
Is it the same as cold laser or red light therapy?
They're related, but they aren't the same thing. All of them aim light at the body, and the main difference is power.
- Cold laser. A 2026 review in Lasers in Medical Science describes low-level laser, the kind usually called cold laser, as under 0.5 watts.
- High-intensity laser. The same review puts high-intensity laser above 0.5 watts, usually at longer infrared wavelengths.
- The Horizon. Summus lists up to 28 watts of continuous power at 650, 810, 915 and 980 nanometers. That puts it in the FDA's highest laser class, Class IV.
- Red light therapy. This usually means LED panels, pads or beds, and LEDs aren't lasers. The Horizon's 650 nanometer beam is visible red light, and the other three are near-infrared.
If it's an LED or red light treatment you're after, give us a call and we'll tell you what we offer.
What the research on high-intensity laser shows
Reviews of high-intensity laser have reported less pain in several of the areas where we use it:
- Low back. A 2023 meta-analysis found lower pain after treatment with high-intensity laser than in the comparison groups in adults with low back pain.
- Neck. A 2023 review of 8 randomized trials found high-intensity laser may improve neck pain and some neck movements compared with placebo, on moderate-quality evidence. The authors suggest it as an add-on to other care.
- Knee. In a 2023 review of nine studies in people with knee osteoarthritis, all nine reported less knee pain with high-intensity laser. The authors called it promising, especially combined with exercise.
- Shoulder. A 2024 review of six trials with 284 people with shoulder impingement found high-intensity laser did better than conventional therapy for pain and arm function, both right after treatment and three months later.
- High-intensity against low-level laser. A 2026 analysis of 22 randomized trials with 1,353 people found high-intensity laser reduced pain a little more than low-level laser in some comparisons, especially alongside exercise.
For the heel, a 2026 meta-analysis of 13 randomized trials with 784 people with plantar fasciitis, pooling low-level and high-intensity laser, found laser may reduce heel tenderness, though not overall heel pain. The authors recommend it as an add-on to other treatment.
Reviews of laser therapy pool trials of many devices and settings, and a 2024 overview rated the methods of most of those reviews low or critically low. So the research describes high-intensity laser as a kind of treatment, not the Horizon specifically or how you personally will respond. It's also why we use the laser alongside other care rather than on its own.
Safety, and the other options
The main risk with a Class IV laser is to the eyes and skin from the beam, which is why eye protection and correct operation matter. Tell us right away if the warmth ever feels uncomfortable. If an area has reduced feeling, we take that into account at your exam, because you may not feel heat there.
Laser isn't the only option for muscle and joint pain. For low back pain, NICE, England's national guideline body, recommends staying active and exercise, with hands-on care as part of an exercise-based plan. Your medical doctor or a physical therapist can help too. We'll go over the options that fit your problem at your exam, and our neck, shoulder and knee pages cover them for each area. A licensed massage therapist also works out of our office.
Cost
The new-patient chiropractic offer has its own terms. Laser has its own fee, and the office can confirm it before you agree to it.
Book a visit
If your back, neck, shoulder, knee or heel is sore or stiff, a first visit is where we'd work out whether laser belongs in your plan. If we aren't able to help you or reduce your pain levels, we'll make sure to recommend another experienced provider. Contact us to book.
Follow the evidence
Research, with context.
Selected published sources behind what we've written, each with what it found and what it can't tell us. We give you both halves because no paper can diagnose you or predict how your own care will go.
High-intensity laser therapy in low back pain management: a systematic review with meta-analysis
Randomized trials in adults with low back pain, published before January 2023, comparing high-intensity laser with control treatments.
What it foundPain after treatment was lower with high-intensity laser than in the control groups, and two disability scores were lower too.
What it can't tell usThe disability results rested on three trials, the pain results varied a fair amount between trials, and the abstract doesn't weigh the differences against the change patients consider meaningful.
Publication details & citation
Abdildin et al. High-intensity laser therapy in low back pain management: a systematic review with meta-analysis. Lasers in Medical Science. 2023. DOI: 10.1007/s10103-023-03827-w.
Read the publication recordThe effectiveness of high-intensity laser therapy in individuals with neck pain: a systematic review and meta-analysis
8 randomized trials of high-intensity laser in people with neck pain.
What it foundCompared with placebo, high-intensity laser may improve pain and some neck movements, on moderate-quality evidence. The authors suggest it as an add-on treatment.
What it can't tell usLow-quality evidence found no clear benefit for everyday function, and there was little information on quality of life.
Publication details & citation
Xie et al. The effectiveness of high-intensity laser therapy in individuals with neck pain: a systematic review and meta-analysis. Physiotherapy. 2023. DOI: 10.1016/j.physio.2023.07.003.
Read the publication recordHigh-intensity laser therapy on pain relief in symptomatic knee osteoarthritis: A systematic review and meta-analysis
9 studies of high-intensity laser for knee osteoarthritis pain, compared with sham laser, other lasers, conventional physiotherapy or exercise.
What it foundAll nine studies reported less knee pain with high-intensity laser. The authors called it promising, especially combined with exercise.
What it can't tell usThe comparison against a sham laser rested on two studies with 136 people over a short course of treatment.
Publication details & citation
Cai et al. High-intensity laser therapy on pain relief in symptomatic knee osteoarthritis: A systematic review and meta-analysis. Journal of Back and Musculoskeletal Rehabilitation. 2023. DOI: 10.3233/BMR-220228.
Read the publication recordEffects of high-intensity laser therapy on subacromial impingement syndrome: a systematic review and meta-analysis
6 trials, five of them randomized, with 284 people with shoulder impingement, comparing high-intensity laser with conventional therapy.
What it foundHigh-intensity laser did better than conventional therapy for pain and for shoulder and arm function, right after treatment and three months later.
What it can't tell usIt made no difference to shoulder flexion or outward rotation, and six trials is a small base.
Publication details & citation
Hao et al. Effects of high-intensity laser therapy on subacromial impingement syndrome: a systematic review and meta-analysis. Lasers in Medical Science. 2024. DOI: 10.1007/s10103-024-04190-0.
Read the publication recordEffect of Local Laser Therapy on Plantar Fasciitis: A Meta-Analysis
13 randomized trials, 784 participants with plantar fasciitis, comparing laser therapy with placebo or other physical treatments.
What it foundLaser therapy may reduce heel tenderness. It showed no significant difference in overall pain, function or the thickness of the plantar fascia.
What it can't tell usThe trials mixed low-level and high-intensity lasers, and the pain and function results were highly inconsistent between trials. The authors say laser should be considered an add-on, not a primary treatment; the result doesn't describe any one device.
Publication details & citation
Ortiz-Romero et al. Effect of Local Laser Therapy on Plantar Fasciitis: A Meta-Analysis. Journal of Clinical Medicine. 2026. DOI: 10.3390/jcm15031307.
Read the publication recordComparison of the effectiveness of high-intensity laser therapy versus low-level laser therapy in musculoskeletal disorders: a systematic review and network meta-analysis
22 randomized trials with 1,353 people with muscle and joint disorders, comparing high-intensity laser with low-level laser, placebo laser or other treatments.
What it foundHigh-intensity laser reduced pain a little more than low-level laser in some comparisons, especially alongside exercise or other physical therapy.
What it can't tell usThe differences were generally modest and often smaller than the change considered clinically important, and the certainty of the evidence was mostly very low. The authors advise caution and placing laser within a broader rehabilitation plan.
Publication details & citation
de la Barra Ortiz et al. Comparison of the effectiveness of high-intensity laser therapy versus low-level laser therapy in musculoskeletal disorders: a systematic review and network meta-analysis. Lasers in Medical Science. 2026. DOI: 10.1007/s10103-026-04812-9.
Read the publication recordQuality appraisal of systematic reviews on high-intensity laser therapy for musculoskeletal pain management: an umbrella review
20 systematic reviews of high-intensity laser for muscle and joint pain, including the knee, shoulder, neck, low back and plantar fascia.
What it foundThe reviews reported pain relief across several conditions, with the largest effects in reviews of spinal disorders, frozen shoulder and neck pain.
What it can't tell usIt rated the reviews' own methods generally low to critically low in quality, with weak handling of publication bias and funding disclosure, so the pooled results are less certain than they look.
Publication details & citation
de la Barra Ortiz et al. Quality appraisal of systematic reviews on high-intensity laser therapy for musculoskeletal pain management: an umbrella review. Lasers in Medical Science. 2024. DOI: 10.1007/s10103-024-04241-6.
Read the publication record
Our editorial policy explains how to read these sources and what our clinical-review labels mean.