Physical Modalities in Sports Medicine

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General Indications

Pain
Muscle spasm
Contracture
Tension myalgia
Hematoma resolution
Bursitis
Tenosynovitis
Fibromyalgia
Superficial thrombophlebitis
Acceleration of metabolic process

General Contraindications and Precautions

Acute inflammation, trauma, or hemorrhage
Bleeding dyscrasia
Ischemia
Insensitivity
Atrophic skin
Scar tissue
Inability to communicate
Poor thermal regulation (systemic applications)
<DIV span classtion:The process of heat energy transfer between a solid object and a moving gas or liquid.

Conversion: The process of energy transfer that involves converting one form of energy to a different form. Use of high-frequency sound waves or electromagnetic (EM) waves to heat tissue will be discussed.

Heating modalities are divided into superficial and deep.

PHYSIOLOGY OF SUPERFICIAL HEAT

Predominant mode of heating is conduction; however, some superficial applications use convection or conversion.
Superficial heat effects include vasodilatation, pain relief, reduction of muscle tone and spasticity, increased cellular metabolic activity, decreased joint stiffness, increased soft tissue extensibility, and promotion of hyperemia. Elevation of tissue temperature does not generally exceed 40°C and is usually short lived.
Causes superficial vasodilatation preferentially.
May be associated with consensual vasodilatation of areas distant to the area being heated; for example, the contralateral limb.
Changes of 13-15°C in the finger joint may change joint viscosity by about 20% (93).
There is moderate evidence that heat wrap therapy provides short-term pain reduction and disability in patients with acute and subacute low back pain. There is further pain reduction and functional improvement with the addition of exercise (<A onclick="if (window.scroll_to_id) { scroll_to_id(eveslowly decreasing 1/r relationship.

Safety: These agents produce erythema (known as erythema ab igne and erythema calor).

Chronic use may produce a permanent brownish discoloration.

Hydrotherapy

Heat tran”P”>Contracture
Tension myalgia
Hematoma resolution
Bursitis
Tenosynovitis
Fibromyalgia
Superficial thrombophlebitis
Acceleration of metabolic process

General Contraindications and Precautions

Acute inflammation, trauma, or hemorrhage
Bleeding dyscrasia
Ischemia
Insensitivity
Atrophic skin
Scar tissue
Inability to communicate
Poor thermal regulation (systemic applications)
Malignancy
Edema

Application Methods

Hot Packs (Hydrocollator)

Transfer of heat energy by conduction
Application: Silicate gel in a canvas cover
When not in use, these packs are kept in thermostatically controlled water baths at 70-80°C.
Used in terry cloth insulating covers or used with towels placed between the pack and the patient for periods of 20-30 minutes.
Advantages: Low cost, easy use, long life, and patient acceptance
Disadvantages: Difficult to apply to curved surfaces
Safety: One should never lie on top on the pack, as it is more likely to cause burns. Towels should be applied between the skin and hydrocollator pack.

Heat Lamps

Heat primarily by the conversion of radiant energy to heat, i.e., the direct application of photons to living tissue leading to heat production.
Application: Simple to use but require some attention to avoid injuries or burns.
In practice, therapeutic temperatures are usually obtained when the heat sources are about 50 cm from the skin.
The intensity of heating of point heat sources, such as incandescent bulbs, drops off in accordance with the inverse squared (1/r²) law; the heating effectiveness of linear sources, such as some quartz lamps, may follow a more nsuming.

Contrast Baths

Application

Contrast baths consist of two baths: a warm bath at 38-44°C and a cool reservoir at about 10-18°C.
Treatment begins by soaking the involved limb in the warm reservoir for about 10 minutes and then progressing to about four cycles of 1- to 4-minute cold and 4- to 6-minute warm soaks (92).

Advantages/Disadvantages

Most commonly used to produce reflex hyperemia and desensitization in patients with complex regional pain syndrome.
Athletes may find the cold baths uncomfortable.
May increase superficial blood flow and skin temperature; however, no effect on functional outcome (17).

Spa Therapy (Balneotherapy)

Little research has addressed these issues for athletes.
In addition, a comparison of the effects of spa therapy, underwater traction, and water jets on low-back pain found no specific benefits attributable to balneotherapy (58).

Fluidotherapy

Application

Heats by convection: Fine particles fluidized by turbulent, high-velocity hot air, frequently used in hand therapy.
Despite widespread use, benefits of this high temperature remain poorly established (
Disadvantages
- Should not be used with edematous limbs.
- Treatment systems and infection control are time consuming.

Contrast Baths

Application

Contrast baths consist of two baths: a warm bath at 38-44°C and a cool reservoir at about 10-18°C.

Treatment begins by soaking the involved limb in the warm reservoir for about 10 minutes and then progressing to about four cycles of 1- to 4-minute cold and 4- to 6-minute warm soaks (92).

Advantages/Disadvantages

Most commonly used to produce reflex hyperemia and desensitization in patients with complex regional pain syndrome.
Athletes may find the cold baths uncomfortable.
May increase superficial blood flow and skin temperature; however, no effect on functional outcome (17).

Spa Therapy (Balneotherapy)

Little research has addressed these issues for athletes.
In addition, a comparison of the effects of spa therapy, underwater traction, and water jets on low-back pain found no specific benefits attributable to balneotherapy (58).

Fluidotherapy

Application

Heats by convection: Fine particles fluidized by turbulent, high-velocity hot air, frequently used in hand therapy.
Despite widespread use, benefits of this high temperature remain poorly established (3,<A onclick="if (window.scroll_to_id) { scroll_to_id(event,'R16-69'); return false; }" onmouseover="window.status=this.title; return true;" onmouseout="window.status=''; return true;" title=25 class=LK href="#R16-69" name=to-R16-69 xpath="/CT{06b9ee1beed59419fa2bedb3ing heating agent can elevate intramuscular temperatures by about 3.5-4.0°C (25).
Penetration is not uniform and depends markedly on tissue properties: Ultrasound beam will selectively heat tissue with high water content.
The ability of ultrasound to heat tissue by the conversion of sound energy into heat is its best-understood capability.
Nonthermal processes such as cavitation, shock waves, streaming, and mechanical deformation have been identified.
Cavitation occurs when small gaseous bubbles are formed in the presence of a high-intensity ultrasound beam and either oscillate stably or grow rapidly in size and collapse (28).
No irreversible harmful effects of cavitation have been demonstrated in animal tissue (Treatment: Dipping, immersion, occasionally brushed onto the area of treatment.
Safety: Burns are the main safety concern with paraffin treatment.
Visual inspection is important: Paraffin bath should have a thin film of white paraffin on its surface or an edging around the reservoir.

DIATHERMY (DEEP HEATING)

The following differences set diathermy apart from superficial heating:
- Produces higher temperatures
- Heats tissue faster and heat dissipates more slowly
- Predominantly uses sound waves or EM energy

Deep Heating Modalities

Ultrasound

Ultrasound is defined as sound waves at a frequency above the threshold of human hearing (frequencies higher than 20 kHz).

Heats by Conversion

Ultrasound uses sound waves to heat tissues. A wide range of frequencies are potentially useful, but in the United States, most machines operate between 0.8 and 1 MHz.
Uses piezoelectric transducers to convert electrical energy into sound.

Physiology

The most vigorous and deeply penetrat2) accelerates bone healing and is approved by the Food and Drug Administration (FDA) for the treatment of some fractures (36).
Low-intensity pulse ultrasound eam will selectively heat tissue with high water content.
The ability of ultrasound to heat tissue by the conversion of sound energy into heat is its best-understood capability.
Nonthermal processes such as cavitation, shock waves, streaming, and mechanical deformation have been identified.
Cavitation occurs when small gaseous bubbles are formed in the presence of a high-intensity ultrasound beam and either oscillate stably or grow rapidly in size and collapse (28).
No irreversible harmful effects of cavitation have been demonstrated in animal tissue (31).
Streaming is described as movements in water-rich tissues and standing waves. Streaming may damage tissue or possibly speed healing.
Typical intensity for application is 0.8-1.5 W/cm².
Low-intensity ultrasound (15-400 mW/cm²) may also stimulate cell proliferation, protein synthesis, and cytokine production. Although these findings are limited to the laboratory, they furnish some support for the clinical interest in low-intensity ultrasound in wound healing.

Indications

Tendonitis and bursitis
Muscle pain and overuse
Contractures
Inflammation and trauma
Scars and keloids
The evidence is mixed. In most cases, ultrasound comparisons have been performed against placebo controls; therefore, the relative effectiveness of this agent over that of other conventional approaches is unknown. There is, however, promising evidence of effectiveness in lateral epicondylitis (85).
Fractures: Low-intensity ultrasound (e.g., 30 mW/cm^{t,’R27-69′); return false; }” xpath=”/CT{06b9ee1beed59419fa2bedb37ace85f4ef50397bb3c2ea48f132154d6696ac7a2f84c1baffad7dc7157c0b06ebf6e33a}/ID(R27-69)” title=”27″ onmouseover=”window.status=this.title; return true;” onmouseout=”window.status=”; return true;”>27,87,88)}
Acute hemorrhages, ischemic tissue, tumors, laminectomy sites, infections, and implanted devices such as pacemakers and pumps
Caution: Relatively contraindicated near metal plates or cemented artificial joints because the effects of localized heating (19,34,<A onclick="if (window.scroll_to_id) { scroll_to_id(event,'R79-69'); return false; }" class=LK href="#R79-69" name=to-R79-69 xpath="/CT{06b9ee1beed59419fa2bedb37ace85f4ef50397bb3c2ea48f132154d6696ac7a2f84c1baffad7dc7157inical studies are conflicting.

In a comparison of phonophoresis of 0.05% fluocinonide with ultrasound alone at 1.5 W/cm², both treatments were found to be beneficial but were indistinguishable in their effects on superficial musculoskeletal conditions (55).