Physical Agents: Valuable Adjuncts to Physical Therapy Interventions







Therapeutic physical agents or modalities—valuable adjunctive tools in physical therapy



Physical agents such as heat, cold, light, sound, electricity, air, and electromagnetic radiation used in a therapeutic fashion to affect physiological responses in an effort to ameliorate specific signs and symptoms of pathology are crucial adjuncts to the provision of physical therapy care.

Therapeutic modalities should not be applied in isolation or in a vacuum. Modalities are adjunctive to treatment. A hot pack by itself may not be effective. However when combined with the appropriate stretching, special techniques, and therapeutic exercise, its use may prove invaluable.

In part, this course introduces and discusses the use of thermal and low-level laser modalities in clinical PT management of common conditions.




Superficial Heat Modalities



Heat is a form of energy associated with the motion of atoms or molecules in matter and capable of being transmitted through media by conduction, through fluid media by convection, and through empty space by radiation. Generally, superficial heat modalities only heat structures less than 1 centimeter deep to the skin.



Deep Heat Modalities



Deep heat modalities heat tissues between 3 to 5 centimeters below the level of the skin. In other words when the goal is to heat deep muscle and most joint components (capsules, ligaments, etc.) deep heating modalities are required. The most common deep heat modalities are ultrasound and short wave diathermy.



Ultrasound



Therapeutic ultrasound is a pressure wave applied to tissues at a level of intensity that is so low and at a frequency that is so rapid, the pressure itself cannot be detected by the person receiving it. These pressure waves are transmitted to a small volume of tissue, which causes the molecules of the tissue to vibrate.



Shortwave Diathermy



Diathermy devices deliver electromagnetic waves to tissues. Electromagnetic waves are energy waves that are propagated through space. Though the waves themselves cannot be detected, they cause biophysiological effects as they pass through and interact with body tissues.



Low Level Laser





Laser is an acronym for light amplification by stimulated emission of radiation. Laser works at the tissue and cellular level stimulating physiological changes that may promote healing, decrease pain, and other effects.