Laser therapy

Fact CheckedMedically reviewedSources
This content is medically reviewed or fact checked to ensure factually accurate information. With strict sourcing guidelines, we only link to academic research institutions and when research is available, medically peer-reviewed studies. The information in our articles is not intended to replace a one-on-one relationship with a qualified health care professional and is not intended as medical advice. More…
Last Medical Review: April 6, 2020
Medically Reviewed by Dr. Luis Alberto Vallejo
What is laser therapy? (April 6, 2020)
Low Level Laser Therapy (April 6, 2020)

What is laser therapy?

It is a technique by which energy from the electromagnetic spectrum is applied to the organism to facilitate its biochemical activity.

The energy must be measured and calibrated so as not to saturate the living environment or on the contrary it is insufficient.

Laser means Light by Amplification Stimulated Emission of Radiation.

Electromagnetic spectrum

It is the one that designates all the wavelengths of radiation emitted by a substance. It extends from values ​​of wavelengths of the order of tens of Km. Up to 10-14 m.

It can be measured in two different ways:

  • By the frequency of oscillation of the waves.
  • For the wavelength between two successive crests.

The region between 10 km and a few meters corresponds to frequencies of the order of 10-4 to 107 Hz. They are used in broadcasting and require the use of conventional components and circuits.

The continuous region corresponding to wavelengths of 10-1 to 10-3 m constitutes the microwave region.

From the wavelength of 10-4 m and up to 10-8 m the methods of obtaining radiation differ from the previous ones. In this range is the so-called optical spectrum, where the region visible by the human eye is called the visible spectrum, between 3,300 and 7,700.

The light spectrum represents the most important field for man within the electromagnetic system.

It is made up of the frequencies in which the colors of the rainbow are presented and covers wavelengths between 760 and 380 nm.

The shorter wavelengths correspond to the regions of the RX and Gamma.

– Electromagnetic waves:

They are a vibratory disturbance produced by the simultaneous variation of two fields, electric and magnetic that usually vibrate in two perpendicular planes. For example radio waves and light.

Physical parameters of the laser:

Wavelength: It is the distance traveled by the wave in a period. It is represented by the symbol “l” and its unit is the meter. The greater the number of cycles performed in a second, the shorter the distance traveled or wavelength.

Power: It is the speed with which a job is performed. Using electrical energy is the product of VI. In this case it is used to measure the speed with which the transformation of one energy into another occurs. It is represented as “P” and is measured in Watts.

It is also defined as the ability to carry out a job.

How is the laser produced?

Certain electrons can jump into a state of metastability, temporarily they are at a higher level of energy because they have been raised to orbits farther from the primitives by adequate stimulation.

By causing the return of the electron to its normal situation, photonic stimulation is achieved.

The external energy that this production requires can be thermal, light, electric or chemical and its contribution is known as the “pumping system”.

Effects of laser therapy

– Biological effects of the laser:

  • Analgesia in the irradiated area
  • Anti edematous
  • Heal wounds and injuries in various tissues.

– Laser photothermal effect

  • It constitutes a form of “message” or usable energy (mW) by the cell itself for the normalization of altered functions.
  • It is a photo energetic or bioenergetic effect.

– Laser photochemical effect

  • The release of substances such as histamine, serotonin and bradykinin occurs.
  • Increased production of intracellular ATP.
  • Stimulation of DNA synthesis, protein and enzymatic synthesis.

– Laser photoelectric effect

  • Normalization of the membrane potential acting directly on ionic mobility and indirectly by increasing the ATP produced by the cell and necessary to make the sodium and potassium pump functional.

Laser types

1-Helio Neon Laser

  • It comes from the mixture of both gases.
  • It emerges in the form of a parallel beam, very fine collimated without loss of power with distance.
  • It is emitted in the red band with a wavelength of 632.8 nm.
  • It is of continuous emission.
  • The emitted power is effective. Its powers are very low 15, 17, 20, 50 mW, requiring prolonged sessions.
  • It can be pressed.
  • Its effects are based on biochemical transformations, amino acid synthesis and protein chains in which visible light input is required.
  • Its best effects are observed in the bioactivation of ulcers and burns.

2-Gallium Arsenide Laser

  • It comes from the passage of electrical energy through a diode, known as a semiconductor.
  • It is emitted in the infrared band, with a wavelength between 780 and 905 nm.
  • It is pulsed emission and the effective power must be calculated.
  • It is applied by point-to-point head for low power or by barrel with divergent sweep in which they exceed 1 W of effective power.
  • It is used with better results in anti-allergic therapy.
  • Its effects are supported by energy input that the organism’s electrochemistry requires to accelerate its energy and synthesis metabolism.

3- Diode laser

  • The diode is an electronic component consisting of two minerals of different electrical characteristics.
  • Both minerals put in contact let an electric current in one direction.

Therapeutic laser dose:

It will depend on a series of parameters that the physiotherapist must establish according to the diagnosis, type of tissue, different therapeutic effects etc.

To influence the energy we only control the application time.

Laser application methods:

  • Punctual: at a predetermined point or points, acupuncture points etc. They are applied with the scanner focused on a fixed point.
  • Sweep points: applied from cannon systems with mirrors.
  • Total sweeping of an area: by means of cannon systems that control mirrors, drawing a sway of the collimated beam

Indications of Laser therapy

  • Ulcerative processes
  • Varicose processes
  • Tenosynovitis
  • Capsulitis and bursitis.
  • Fibromyalgia
  • Fasciitis
  • Fibrosis.
  • Cellulitis.
  • Tissue tears, effusions and bruises.


  • They are not clearly established or defined.
  • In malignant processes the response must be observed.
  • The greatest danger is in direct exposure or reflected by mirrors or reflective objects.
  • The physiotherapist must act prudently at all times and continually await new conclusions and advances.

Leave a Reply

Your email address will not be published. Required fields are marked *

Back to top button