Cryotherapy | Application of Cold.

While doing his daily activity little Sam twisted his ankle and experience sharp pain. His mother Miranda applied an ice pack on his ankle and within 5 minutes pain is reduced.

This makes Sam amazed and curious that 5 minutes before he experienced a sudden pain which is now tolerable. But how?

Like Sam sometimes we all get curious that how this little calm cold piece gives sudden change on the injury to reduce the pain, well it’s not only ice but also the use of low temperature frozen gel pack and vapour coolant spray give the same effect.

But how does this happen? Well there is a little interesting science behind it. Let’s see what is it.

Latent heat: A concept that says a form of energy released or absorbed by a substance during a change in it physical state that occur without changing it temperature.

While applying ice on skin, the skin radiates a considerable amount of energy to change ice into water during this process, body loses heat results in the cooling of the skin, while ice is absorbing the heat emitting from body and changing it structure into liquid but not changing it temperature. 

Conduction: Transfer of heat between two object that are in direct contact with one another. It happens when skin comes in contact with warm or cold object.

Latent heat producing two type of responses in human body:

1. Circulatory Response: In response to cold, body try to reserve heat by constriction(shrinking) it blood vessels. This homeostatic response allows the part to become cold. After a while, a short period of vessel enlargement cause dilation(expand) of blood vessel and then a short interval of dilation and constriction of the vessel is seen.

2. Neural Response: There is a large number of thermal receptors present in the skin. In which the amount of cold receptors is larger in quantity than the warm receptors.When the cold is applied these cold receptors activates and send signals to the spinal cord.

Large number of  cold receptors decrease nerve conduction velocity of both sensory and motor nerves of warm receptors and have a greater effect on small diameter fibre than large diameter fibre.

Effects of Cold Pack Application:

1. Reduction of pain: One of the oldest technique in relieving pain is using ice. The mechanism involved in the activation of a large number of thermal receptors generating signal and blocking other pain signals travelling towards the spinal cord.

In response to such strong signals, mid brain stimulates to release Beta endorphin which gives temporary relief.

During this period if therapeutic exercise will be done under the observation of qualified physiotherapist, muscle strengthening, and transient pain relief also be achieved.

2. Reduction of spasticity: Cold decreases spasticity for a temporary period of time. On application, it decreases the activity of afferent spindle and Golgi tendon organ activity.

A 30 min of application of ice decrease the spasticity lasting for 1-1.5 hours.

During the temporary decrease of spasticity, therapeutic activity under a qualified physiotherapist carried on to increase muscle strength and endurance.

3. Reduce muscle spasm: Spasm is a state of muscle response to injury or pain, in manifesting as an increase in muscle tone in a specific area with the apparent aim of limiting movement and further damage. Sometimes it produces in more than needed itself causing pain and resulting in more spasm.

In such condition, cold decrease the muscle tone and abnormal manifestation by inhibiting the signal via thermal receptors.

4. Reduce swelling: After an injury, there is an abnormal demand for metabolic reaction resulting in acute inflammation causing swelling in response to heat.

Cold reduces the metabolic reaction rate and reduces inflammatory changes.

Multiple sclerosis patient symptoms get aggravated in hot climates or with excessive activities. Cryotherapy is found effective in these cases.

Technique of application

Application of ice vary upon the effect required:

1. Cold pack: Crushed ice flakes placed inside a towel folded into an appropriate shape then placed over the injured surface.

2. Ice Towel: A towel dip in cold water is covered in plastic sheath, placed on bed over which patient lie down or covers the injured part directly touching the skin applied directly to the skin. Must be taken under the observation of qualified therapist as chances of ice bite is more in this condition but very effective.

3. Immersion: A technique where only a injured part is immersed in a bucket full of ice. Only arm and legs can be immersed in this process. Very effective but have many disadvantages must be taken under the guidelines of doctor/therapist.

4. Ice massage: A pack of ice cover in cloth or towel massaging on injured part. A useful method as it does not require any machine. the freezer compartment of a domestic refrigerator is sufficient, making this technique useful in small departments, in-ward, and home.

Contraindication:

1. Peripheral Vascular Disease: Condition where impairment in circulation over a particular area. eg, atherosclerosis As vasoconstriction may cause further decreasing circulation.

2. Vasospastic Disorders: in condition like Raynaud’s disease(A condition where smaller arteries supplying blood to your skin narrow, limiting blood circulation causing numbness and cold in some areas of your body like fingers and toes) associated with excessive vasospasm should not be treated as already decreasing circulation will further decrease.

3. Cold Sensitivity/Urticaria: A small number of patients are always there who suffer from the condition of urticaria. Their condition aggravated due to the release of histamine from mast cells, causing local weal formation, itching, and development of erythema.

4. Cardiac Condition: In a patient with 6 months after myocardial infarct, ice treatment must be avoided. The initial application of ice causes a sudden drop in blood pressure, thus causing an increase in heart rate. thus a weak heart is not able to meet this demand.

Precautions:

1. Open wound: the application may delay the healing by impairing circulation and metabolic rate.

2. Cardiac Disease: Caution should be taken while treating patients with cardiac disease. The left shoulder and heart have the same parasympathetic supply, cryotherapy should not be applied over the left shoulder as it may inhibit cardiac function in cardiac patients.

3. Skin hypersensitivity: Some people are intolerable to cold in the form of numbness, pain, or colour changes.

4. Psychological: Some patient gets terrified with ice especially the elderly.

Conclusion:

Little Sam now understood a lot about the nature of ice and is happy that this little thing can do so much in just 5 to 15 minutes of application and there are lots of application ways to get much greater relief.

Now he noticed why his grandpa hates cold water and like warm surfaces.

I hope like little Sam you reader too got valuable knowledge regarding Ice.

Youtube: To know more about application of ice, please see the link below also.

Sources:

1.Electrotherapy Simplified – Basanta Kumar Nanda

2.Clayton’s Electrotherapy: Theory and Practice 9^th edition – Angela Forster and Nigel Palastanga

BY KUNWAR KARAN SINGH

(PHYSIOTHERAPIST)