- Laser therapy effectively uses light to reduce pain, decrease inflammation, and stimulate your body’s natural healing.
- This therapy works by stimulating your cells to produce more energy, aiding in natural healing and recovery.
- Laser therapy offers pain relief, reduces swelling, and helps relax muscles affected by various injuries.
- Your physical therapist will choose the right laser type to target your specific condition effectively.
Table of Contents
- How It Works
- Physical Principles
- Photobiomodulation
- Therapeutic Effects
- Types of Therapeutic Laser
- Low Level Laser Therapy (LLLT)
- High Power Laser Therapy (HPLT)
- CO₂ Laser
- Main Indications in Physiotherapy
- Tendon Pathologies
- Joint Pathologies
- Muscle Pathologies
- Spinal Pathologies
- Other Indications
- How a Session is Conducted
- Preparation
- Treatment
- Typical Protocol
- Contraindications
- Absolute
- Relative
- Scientific Evidence
- Advantages and Limitations
- Advantages
- Limitations
- Frequently Asked Questions (FAQ)
- Does laser therapy hurt?
- How many sessions are needed?
- Is laser therapy safe?
- Can I have laser therapy if I have cancer?
- Is laser therapy alone sufficient?
- Related articles
Laser therapy
Laser therapy is an instrumental physical therapy that uses laser light (Light Amplification by Stimulated Emission of Radiation) for therapeutic purposes, exploiting the biological properties of the interaction between photons and body tissues. In physiotherapy and rehabilitation, laser therapy is used for the treatment of pain, inflammation, and to stimulate tissue repair in numerous musculoskeletal pathologies. It is one of the most widespread and studied instrumental therapies, with a growing body of evidence supporting its effectiveness in specific conditions.
How It Works
Physical Principles
Therapeutic laser emits a beam of light that is monochromatic (a single wavelength), coherent (waves in phase), and collimated (parallel), which penetrates tissues at varying depths depending on the wavelength and power.
Photobiomodulation
The therapeutic effect of laser is based on photobiomodulation: the absorption of photons by cellular chromophores (particularly cytochrome c oxidase in mitochondria) activates a cascade of biological events:
- Increased ATP production: more energy available for cellular processes
- Modulation of reactive oxygen species (ROS)
- Release of nitric oxide (NO): local vasodilation
- Activation of transcription factors: stimulation of cell proliferation and collagen synthesis
Therapeutic Effects
| Effect | Mechanism |
|---|---|
| Analgesic | Increase in pain threshold, modulation of nerve transmission, release of endorphins |
| Anti-inflammatory | Reduction of pro-inflammatory cytokines (IL-1, TNF-α), increase in anti-inflammatory ones |
| Biostimulating | Stimulation of cell proliferation, collagen synthesis, and neoangiogenesis |
| Anti-edematous | Improvement of lymphatic and venous drainage |
| Muscle Relaxant | Reduction of muscle tone in contractures |
Types of Therapeutic Laser
Low Level Laser Therapy (LLLT)
- Power: < 500 mW
- Wavelengths: 630-1000 nm (red and near-infrared)
- Predominantly superficial and biostimulating effect
- Also called “cold laser” because it does not produce perceptible heat
- Used for superficial lesions, trigger points, acupuncture points
High Power Laser Therapy (HPLT)
- Power: 1-25 W (up to 30-50 W in more recent models)
- Wavelengths: 800-1064 nm
- Deeper tissue penetration (up to 5-7 cm)
- Controlled thermal effect (photothermal) in addition to the photochemical one
- Used for deep pathologies: joints, tendons, muscles
- Examples: Nd:YAG laser, high-power diode laser
CO₂ Laser
- High power with a predominantly thermal effect
- Used for superficial treatments (keloids, adhesions, trigger points)
- Less common than diode and Nd:YAG lasers
Main Indications in Physiotherapy
Tendon Pathologies
- Chronic tendinopathies: Achilles, patellar, rotator cuff
- Epicondylitis and epitrochleitis
- Calcific tendinitis (in combination with shockwave therapy)
- Evidence: good for pain reduction and stimulation of tendon repair
Joint Pathologies
- Osteoarthritis: knee, hip, hand, spine
- Adhesive capsulitis of the shoulder
- Rheumatoid arthritis (as a complementary therapy)
Muscle Pathologies
- Muscle contractures
- Strains and tears (in the sub-acute and chronic phase)
- Myalgia and trigger points
Spinal Pathologies
- Low back pain (acute and chronic)
- Cervicalgia
- Radiculopathy (as a complement to rehabilitation)
Other Indications
- Plantar fasciitis
- Carpal tunnel syndrome
- Bursitis
- Scars and post-surgical adhesions
- Ulcers and slow-healing wounds
- Lymphedema (drainage stimulation)
How a Session is Conducted
Preparation
- The skin in the area to be treated must be clean and dry
- Jewelry and metal objects are removed from the area
- Patient and operator wear specific protective eyewear for the wavelength
Treatment
- The physical therapist places the probe (handpiece) on the area to be treated
- The probe is kept in contact with the skin or at a short distance
- The wavelength, power, energy dose (J/cm²), and mode (continuous or pulsed) are set
- The treatment duration varies from 5 to 20 minutes per area
- The patient generally feels a slight pleasant warmth (high-power laser) or no sensation (low-power laser)
Typical Protocol
- Number of sessions: 6-10 sessions (sometimes more)
- Frequency: 2-3 times a week
- Dose: variable based on the pathology, depth, and type of laser (4-12 J/cm² for superficial pathologies, up to 50-100 J/cm² for deep structures with high-power laser)
Contraindications
Absolute
- Direct irradiation of the eyes (without protection)
- Neoplasms in the area to be treated (risk of stimulating tumor growth)
- Pregnancy on the abdominal and pelvic region
- Irradiation on the thyroid
Relative
- Epilepsy: caution with the use of pulsed lasers
- Photosensitivity (photosensitizing drugs)
- Areas with loss of sensation (risk of unperceived burn)
- Active infections in the area to be treated
- Dark tattoos in the area (excessive absorption)
- Pacemaker: caution, do not irradiate directly
Scientific Evidence
Therapeutic laser emits monochromatic, coherent light that penetrates tissues, stimulating cellular energy production and reducing pain, inflammation, and promoting tissue healing. The evidence on laser therapy is heterogeneous due to the wide variability of treatment parameters (wavelength, power, dose, duration).
Good evidence:
- Cervical and lumbar pain (short-term pain reduction)
- Chronic tendinopathies (in combination with exercise)
- Lateral epicondylitis
- Knee and hand osteoarthritis (pain reduction)
- Ulcer healing
Moderate evidence:
Recommended product
Il calore infrarosso favorisce la vasodilatazione e il rilassamento muscolare, complementando gli effetti della laserterapia nella gestione del dolore.
Lampada a infrarossi per terapia del calore — View on Amazon
(paid link)
- Adhesive capsulitis
- Carpal tunnel syndrome
- Plantar fasciitis
Limited or conflicting evidence:
- Fibromyalgia
- Acute muscle injuries
Important note: laser therapy is most effective when used in combination with therapeutic exercise and manual therapy, not as an isolated treatment.
Advantages and Limitations
Advantages
- Non-invasive and painless
- No recovery time after the session
- Few side effects (rare transient redness)
- Applicable to a wide range of pathologies
- Combinable with other therapies
Limitations
- Cost: variable, but can be significant for complete cycles
- Parameter dependency: effectiveness strongly depends on the correct choice of wavelength, dose, and power
- Not a substitute for therapeutic exercise
- Variable effectiveness depending on the pathology and the patient
Frequently Asked Questions (FAQ)
No, laser therapy is generally painless. With high-power laser, a slight pleasant warmth may be felt in the treated area. There are no unpleasant sensations during or after the treatment.
A standard cycle involves 6-10 sessions, with a frequency of 2-3 times a week. The exact number depends on the pathology, its chronicity, and individual response. The first benefits are generally felt after 3-4 sessions.
Yes, it is a very safe therapy when performed by qualified personnel with correct eye protection. Contraindications are few and well-defined. It does not produce significant side effects in almost all patients.
No, laser therapy is contraindicated in the area of an active neoplasm, as cellular stimulation could theoretically promote tumor growth. In case of neoplasm in remission, the decision must be made by the doctor.
In most cases, no. Laser therapy is most effective as part of a comprehensive rehabilitation program that includes therapeutic exercises, manual therapy, and correction of biomechanical causes. Using it as the sole treatment can provide temporary relief but rarely resolves the root problem.
Frequently Asked Questions
How does laser therapy work to promote healing?
Laser therapy operates by delivering specific wavelengths of light, or photons, into the body’s tissues. These photons are absorbed by cells, stimulating cellular metabolism and increasing energy production, which in turn accelerates natural healing processes and tissue repair.
What conditions are commonly treated with laser therapy?
Laser therapy is frequently applied to a variety of musculoskeletal conditions, including tendon, joint, muscle, and spinal pathologies. It is utilized to alleviate pain, reduce inflammation, and stimulate tissue regeneration across these indications.
What should a patient expect to feel during a laser therapy session?
During a laser therapy session, patients typically experience minimal to no sensation. Some individuals may perceive a gentle, soothing warmth in the treated area, but the procedure is generally comfortable and non-invasive.
Is laser therapy typically used as a standalone treatment?
Laser therapy is often incorporated as part of a broader, comprehensive rehabilitation program rather than being used in isolation. A physical therapist commonly combines it with other therapeutic modalities, such as exercise or manual therapy, to achieve optimal patient outcomes.
Sources and Scientific References
- Gebremariam L et al. (2014). Subacromial impingement syndrome–effectiveness of physiotherapy and manual therapy. Br J Sports Med. 48:1202-8. DOI | PubMed
- Qaseem A et al. (2017). Noninvasive Treatments for Acute, Subacute, and Chronic Low Back Pain: A Clinical Practice Guideline From the American College of Physicians. Ann Intern Med. 166:514-530. DOI | PubMed
- Ahmad MA et al. (2022). Effects of low-level and high-intensity laser therapy as adjunctive to rehabilitation exercise on pain, stiffness and function in knee osteoarthritis: a systematic review and meta-analysis. Physiotherapy. 114:85-95. DOI | PubMed
- Zare Bidoki M et al. (2024). Comparison of High-intensity Laser Therapy with Extracorporeal Shock Wave Therapy in the Treatment of Patients with Plantar Fasciitis: A Double-blind Randomized Clinical Trial. Iran J Med Sci. 49:147-155. DOI | PubMed
- Abdildin Y et al. (2023). High-intensity laser therapy in low back pain management: a systematic review with meta-analysis. Lasers Med Sci. 38:166. DOI | PubMed