Thermotherapy(heat and cold therapy)

THERMOTHERAPY

Heat therapy

 

• By increasing the temperature of the skin/soft tissue:

• The metabolic rate and tissue extensibility increase.

• (this is in accordance with van’t Hoff’s statement that any chemical change that is being capable of being accelerated is accelerated by the rise in the temperature)

• An increase in metabolism increases oxygen demand and accelerates tissue healing, it also increases the activity of destructive enzymes, such as collagenase, and increases the catabolic rate.

• The blood flow increases by vasodilatation as a result of increased metabolism due to heat.

Cold therapy(cryotherapy)

• By decreasing the temperature of the skin/soft tissue:

• The initial response of the skin to cooling is an attempt to preserve heat ant this is accompanied by vasoconstriction in which the blood flow decreases. If the cold pack is left on the skin for more than 10 minutes, the blood vessels will dilate afterward by vasodilatation which will prevent hypoxic damage and then alternate periods of constriction and dilatation this is referred to as Lewis’s hunting reaction this is beneficial in the reduction of swelling and repair of damaged tissue.

• One of the major effects of cryotherapy is a reduction of pain. The probable mechanism involved is numbness or analgesic effect on pain neurons and by closing the ‘pain gate’.

• It also helps in the reduction of spasticity and spasm through a decrease in nerve conduction velocities or depressed sensitivity of receptors that are muscle spindle but as these structures are placed deeply it may take considerably longer time to produce sufficient low temperature to affect them. As many of hundreds of nerves with endings on anterior horn cells come from the skin this effect can be achieved by the skin stimulus produced by cold.

• This reduces the pain temporarily. However, if some permanent pain relief is to be achieved some positive physiotherapy in terms of strengthening or mobilization treatment is to be taken in this period of transient pain-free.

The effect of both the therapy depends on the method, the duration, proper temperature, and the depth of the subcutaneous fat.

WHEN TO USE HOT THERAPY AND WHEN TO USE COLD