Ice Therapy and its healing effect
Ice therapy also known as cryotherapy is one of the most widely used treatment modalities used for acute sports injuries. It is cheap, easy to use and requires little time to prepare. The application of ice to an injury,in the acute phase can substantially decrease the extent of the damage. It achieves this in a number of different ways:
- Decreases the amount of bleeding by vasoconstriction into the injury site and so lessens swelling
- Reduces pain
- Reduces muscle spasm
- Reduces the risk of cell death by decreasing the rate of metabolism
- A decreased nerve transmission in pain fibres
- Cold reduces the activity of free nerve endings
- Cold raises the pain threshold
- Cold causes a release of endorphins
- Cold sensations over-ride the pain sensation – known as the pain gate theory
Reduces Bleeding and Swelling
By cooling the surface of the skin and the underlying tissues, ice causes the narrowing of blood vessels, a process known as vasoconstriction. This vasoconstriction leads to a decrease in the amount of blood being delivered to the area and subsequently lessens the amount of swelling. After a number of minutes, the blood vessels re-open (dilate) allowing blood to return to the area. This phase is followed by another period of vasoconstriction- this process of vasoconstriction followed by dilation is known as the Hunting Response.
Although blood still flows into the area the amount of swelling is significantly less than if ice is not applied. This decreased swelling or edema, allows more movement in the muscle and so lessens the functional loss associated with the injury. The swelling associated with the inflammatory response also causes a pressure increase in the tissue and this leads to the area becoming more painful. This pain is intensified by certain chemicals that are released into the blood when the tissue is damaged- hence vasoconstriction from applying ice also decreases pain.
Reduces Muscle Spasm
Muscle spasm is often a response to pain. The muscles surrounding the injury contract to protect it (muscle guarding) and prevent further damage. Ice, being useful for pain relief is therefore beneficial in reducing muscle spasms. However it is also thought that muscle spasms which are not caused by acute injury but more muscle overuse or imbalances can also be reduced through the use of cold therapy. This is not fully understood but is thought to be due to ice slowing the conduction velocity of sensory and motor nerves, as well as the activity of muscle spindle cells (responsible for muscle tone), resulting in a decrease in motor activity.
Decreases Metabolic Rate
By reducing the cells metabolic rate, ice reduces the cells oxygen requirements. Thus when blood flow has been limited by vasoconstriction then the risk of cell death due to oxygen demands (secondary cell necrosis) will be lessened.
An ice pack is any type of container which holds crushed or chipped ice. It can be a plastic bag, towel or specially designed ice bag.. These tend to cool the underlying tissues more efficiently than commercial chemical or frozen gel packs and remain cold for a longer period. They can be held in place if required by an elastic bandage or specialist wrap.
An ice bath can easily be made by half-filling a large container/tub with cold water and ice. The size of the container and depth of the water required depends on the body part to be treated. This is the best method of cooling awkward, bony areas, such as the foot, ankle, hand and elbow. Immediately following injury, submerging the injured body part may not be as beneficial as using a cold pack and compression wrap, as there is no compression (RICE principle). Wrapping the ankle prior to submersion will also prevent maximal cooling by insulating the body part.
Ice can be used to massage the affected area. Usually cubes are frozen with some form of handle (a simple lollypop stick will suffice) in order to protect the hands of the masseur. This method is most suitable for injured muscles and larger areas. The ice should be stroked up and down the injured muscle. The disadvantage of this type of massage is that the application is phasic, that it the ice is in contact with each area only briefly. Following this it is exposed to air temperature which reduces the efficacy of tissue cooling. However, numbing of the area is quite efficient due to the movement of the ice stimulating mechanoreceptors in the muscles.
These commercially available packs contain a gelatinous substance which is kept frozen in a freezer until required. Better examples contain some form of anti-freeze which prevents the gel from freezing into a rigid position, allowing the pack to be molded to the shape of the body part. These are good for use in a clinic setting as they are re useable and not as messy as ice packs. However when taken out of the freezer they immediately begin to thaw and so are not suitable for use on the field of play. They must also be applied to the skin through a towel or cloth to prevent frostbite.
Chemical Cold Packs
These are one use cold packs where compressing and rupturing a central pouch, contained with the pack, releases a second chemical which causes a reaction which lowers the temperature of the pack. These packs do not lower in temperature enough to significantly reduce tissue temperature. They are however convenient for emergency use. Any leak from the pack would cause a chemical burn.
These sprays evaporate quickly when they come into contact with the skin. This removes heat from the skin at the same time. They result in only a very superficial cooling effect and therefore are limited in their efficiency.
The Cryocuff is a machine which consists of a gallon tank of ice water and a nylon sleeve, into which you place the injured part. The ice water flows through the cuff to cool the body part. The tank must be raised to allow more water to flow into the cuff and increase the pressure. In this way compression is also applied to the injury. To cool the water sitting in the cuff, the tank is lowered to allow it to flow back into the tank where it mixes again with the ice water. The tank can then be raised again to fill the cuff. The Cryocuff allows a good degree of cooling and compression, is relatively portable and re useable. Different shaped and sizes of cuff can also be purchased to allow use for all body parts.
Medicated Ice for Abrasions
When a skin injury occurs, the RICE procedure should be followed. In order to also prevent infection the ice you apply can be combined with an antiseptic. In a plastic cup, mix together distilled or boiled water with 10% povidone-iodine and 2% lidocaine. Secure a lollypop stick or similar in the centre with tape and freeze. When required, roll the ice back and forwards over the skin for about 10 minutes. and then treat as normal.
Cooling During Exercise in a Hot Environment
There are a number of suitable methods available to reduce body heat:
- Weak a cold pack around the neck and or forehead during breaks in play
- Drape a towel soaked in ice water over the head
- Wear a Dura-Kold vest or similar
- Have a fan on the sidelines and get athletes to stand infront of it during breaks in play
Minimising Cold Sores and Blisters
If caught early, applying ice can reduce the development of both cold sores and blisters. As soon as you feel either forming, wrap 2/3rds of an ice cube in a cloth or plastic bag and apply the exposed edge directly to the skin. Hold in place for up to 2 hours! Alternatively a bucket of ice water can be used for blisters on the feet, hands or elbows (submerge for 10 minutes).
Ice is usually applied to the injured site by means of a bag filled with crushed ice which is wrapped in a damp towel. The ice should be left in place for approximately 15-20 minutes every hour.