Laser Therapy — How It Works & What It Treats

L.A.S.E.R. stands for Light Amplification by Stimulated Emission of Radiation. Laser Therapy involves the application of low-intensity laser light to relieve pain caused due to the damage of soft tissue. It facilitates tissue repair and restores normal cell function. It is used by experts to heal wounds and pain. The level of light is quite low as compared to other forms of Laser Therapy, such as those used to destroy tumors and coagulate tissues.

CLASSIFICATION BASED ON AEL (Accessible Emission Light)

Class levels 1-4
Class 1- incapable of producing damaging radiation levels
Class 2- power visible lasers (400-700nm wavelength,1nW)
Class 3- medium-power lasers need eye protection
Class 4- high power lasers(more than 500nW)

High Lasers
a. Surgical lasers
b. Hard lasers
c. Thermal lasers
d. Energy (3000-10000 Mw) lasers

Low lasers
a. Medical lasers
b. Soft lasers
c. Subthermal lasers
d. Energy 1-500 mW lasers
e. Therapeutic (cold) lasers produce a maximum output of 90mW or less
f. 600- 1000nm light

High-power lasers
High-power lasers are known as hot lasers because of the thermal response they generate. They are used in surgical cutting, and coagulation conditions, destroy tumors, and coagulate tissues.

Low-power lasers(Cold LASER)
Low power lasers act according to the Arndt-Schulz principle which states that if a stimulus is too weak, no effect is seen. Increased stimulation and optimal dose lead to the optimal effect, while further dose increase leads to a decreased effect and increase leads to inhibition of stimulation is also known as photobiomodulation, used in wound healing and pain management. Low laser is a pain-free, non-invasive method. It has the properties of monochromaticity (same color), collimation (all rays are parallel to each other and do not diverge significantly even over long distances), and coherence (all the light waves are in phase both spatially and temporally).

The Laser has therapeutic effects which help to:

1. Reduce pain
2. Increases ATP (Adenosine Triphosphate) which accelerates the repair process of the cell. Some molecules that increase inflammation are reduced and beneficial antioxidants are increased.
3. Faster wound healing. Laser Therapy is effective on open wounds also.
4. Recovery from nerve injury Reduces aches and pains by decreasing nerve sensitivity.
5. It reduces the formation of Fibrous/Scar tissue. It also improves the vascular activity in the body.
6. Promotes bone and cartilage formation


Most commonly used lasers:

1. Helium-neon (He-Ne) In this laser, a mixture of helium gas and neon is used in a pressurized tube. This creates a laser in the red portion of the electromagnetic spectrum with a wavelength of 632.8nm.

2. Gallium arsenide (Ga-As) It uses a diode to produce an infrared invisible laser at a wavelength of 904nm. Diode lasers are composed of semiconductor silicon that is cut and layered. An electrical source is applied to each side and lasing action is produced at the junction of the two surfaces. The surfaces function as partially reflecting surfaces that produce coherent light. This laser is given in pulsed form because of the heat produced by it.

Preparation of the Patients skin
The skin to be treated is cleaned to lower the skin resistance. Gel sprays or water is applied to the skin to lower the resistance

Calculation of doses
The tissue dose is expressed by energy density measured in Joules per cm2. Produced energy is obtained by multiplying the laser output power in milliwatts by exposition time in seconds. E.g. irradiation area is 0.5cm2, 2 J is divided by 0.5cm2. The time of exposure and the dose becomes 4J/CM2.
The dose is most affected by the size of the laser probe, a slim probe will result in high doses of joules per cm2, but this does not mean that energy applied on the tissue is high, although the intensity of the light the energy emitted at the end of the slim probe is high, but not the dose in the depth

Depth of penetration
He-Ne laser energy: Absorbed rapidly in the superficial structures, especially within the first 2-5mm of tissue. The He-Ne has an indirect effect on the tissues up to 8-10mm.
GaAs laser energy: Ga-As laser which has a longer wavelength is directly absorbed in tissues at depths of 1-2cm and has an indirect effect up to 5cm.

Contact technique: Gas is only given for trigger points and around wounds

Non-contact technique: For He-Ne and Ga-As for healing of wounds and for stimulation of wound beds.

With broad-ranging benefits, LASER Therapy is appropriate for a lot of treatment plans. Some of them are:

1. General Chronic Pain
2. Tennis elbow
3. Plantar fasciitis
4. Shoulder impingement
5. Frozen shoulder
6. Disc herniation
7. Sciatica
8. Pelvic Dysfunction
9. Osteoarthritis of the knee, hip, and ankle
10. Rheumatoid arthritis
11. Tendonitis
12. Tennis Elbow
13. Temporomandibular Joint
14. Diabetic Neuropathy
15. Hip or shouder bursitis

Laser therapy is generally a painless and non-invasive treatment. Patients often report a warm sensation during the procedure, but it should not cause discomfort. The laser device is typically applied directly to the skin, and the therapist will move it over the targeted area. The sensation may vary among individuals, but most find it to be a comfortable and soothing experience.

Laser therapy is considered safe when administered by trained professionals. However, there can be some mild and temporary side effects, including:

1. Redness: The treated area might appear slightly red, similar to a mild sunburn, but this usually dissipates within a few hours.
2. Tingling or warmth: Some patients may feel a tingling or warm sensation during or after the treatment, which is generally mild and temporary.
3. Skin irritation: In rare cases, there may be a slight irritation or rash at the treatment site, but this is uncommon and typically resolves on its own.

It's important to note that serious side effects are rare, but individuals with certain conditions or medications may need to consult with their healthcare provider before undergoing laser therapy.

The number of laser therapy sessions required varies depending on the condition being treated, its severity, and individual response to the therapy. Acute conditions may show improvement after just a few sessions, while chronic conditions may require more extended treatment plans.
Typically, a course of laser therapy might involve multiple sessions scheduled over several weeks. Physiotherapists will assess the progress and adjust the treatment plan accordingly. The frequency of sessions may decrease as the patient experiences improvement. It's essential to follow the therapist's recommendations for the most effective outcomes. Our physiotherapy experts recommend 3 to 4 sessions per week for 20 to 25 minutes for optimum results.

While laser therapy can be effective for various conditions, it's essential to follow precautions to ensure the safety of both the person giving and receiving the treatment. Here are some general precautions to consider:

1. Protective Eyewear: Always wear appropriate protective eyewear designed for the specific type of laser being used. This helps prevent accidental exposure to laser radiation, which can be harmful to the eyes.
2. Skin Protection: Use protective measures, such as gloves, to avoid direct skin contact with the laser. This is especially important when treating individuals with compromised skin integrity or infections.
3. Skin Sensitivity: Be cautious when treating individuals with hypersensitivity to light or those with skin conditions. Adjust the laser settings or consider alternative treatments if necessary.
4. Communication: Encourage open communication between the person receiving the treatment and the practitioner. Ensure the patient feels comfortable expressing any concerns or discomfort during the session.·

1. Eye: Laser beams should not reach the eyes, therefore the use of spectacles is necessary
2. Cancer: Do not use it over the cancerous part of the body.
3. Epileptics: Do not use in epileptic patients.
4. Pregnancy: The laser rays should not reach the fetus.