• Cryotherapy or ice therapy is the application of cold to the body tissues after injury. This practice is as old as medicine itself.• Nowadays, local cold application may be applied by the use of various forms of ice or frozen gel packs, or by evaporation of volatile fluids from the skin. Often skin temperature is reduced to 10 C°.
Physical Principles• When ice is applied to the skin, heat is conducted from the skin to the ice in order to melt it.• To change its state, ice requires considerable energy that is known as latent heat of fusion.• A specific amount of energy required to change the solid form of a particular substance into a liquid, or the liquid into a gas. This energy is called Latent Heat and is the energy required to change of state.
Factors affecting heat loss• Temperature changes in the tissues will depend on both the rate and amount of heat energy removed.• The colder the application the greater the heat loss from the tissue.• In general , water filled tissue, such as muscle, have a high thermal conductivity compared to fat or skin. Thus the cooling of deeper tissue depend on the nature of overlying tissue.• The amount of energy loss is clearly dependent on length of time of cold application.• Larger the area the more heat energy is lost.
Physiological Effects of Cold Application• Circulatory Response• The initial skin reaction to cooling is an attempt to preserve heat. It is accomplished by an initial vasoconstriction. This haemostatic response has the effect of cooling of the body part.• After a short period of time, the duration depends on the area involved, a vasodilatation follows with alternating periods of constriction and dilatation. This reaction of “hunting” for a mean point of circulation is called “Lewis’s Hunting Reaction”.• During the vasodilatation, the arteriovenous anastomosis is closed, thus causing an increase blood flow through the capillaries. This is beneficial in the treatment of swelling and tissue damage.
Lewis’s hunting reaction Hunting response A reflex increase in vasodilatation that occurs in response to cold approximately 15 minutes into the treatment.
• The initial vasoconstriction is often used to limit the extravasations of blood into the tissues following injuries (e.g. sports injuries). Ice therapy is then usually followed by some forms of compression bandage.• The alternate periods of vasoconstriction and vasodilatation affect the capillary blood flow and it is across the capillary membrane that tissue fluid can be removed from the area and returned in the systemic circulation. Increased circulation allows more nutrients and repair substances into the damaged areas.
• Thus ice therapy is very useful in removing swelling and accelerating tissue repair. i.e. ice cubes massage may be used to accelerate the rate of repair of pressure sores.• The reduced metabolic rate of cooled tissues allows cooled muscle to contract many more times before fatigue sets in.
2. On metabolic rate• The principal effect of cooling living tissue will be to reduce its metabolic rate in accordance to Van’t Hoff Law.• It states that the rate of any chemical action that can be affected is increased/decreased by a temperature rise/fall.• Metabolism being a series of chemical reactions will decrease with a fall of temperature.• The actual change is about one eighth for each 1˚C.
3.Neural response/peripheral nervous system• The skin contains primary thermal receptors. Cold receptors are several times more numerous than warm receptors. The cold receptors respond to cooling by a sustained discharge of impulses, the rate of which increases with further cooling.• The rate of conduction of nerve fibers in a mixed (motor and sensory) peripheral nerve is reduced by cooling. The first fibers affected by gradual cooling are the A fibers (myelinated) and eventually at very low temperatures the B and C fibers (non-myelinated) are affected.• Synaptic transmission can also be delayed.• This effect is helpful in treating pain and hypertonicity.
4.On motor system• Muscle strength is seen to diminish on cooling the limb in water at 10-15 C probably because of its effect on viscosity and metabolic rate.• But there are evidences that the strength increases over the original value about an hour or so after cooling has ceased.
Excitatory Cold Mechanism• When cold is applied in an appropriate way on the skin, ice can be used to increase the excitatory bias around the anterior horn cell.• Combined with other forms of excitation (brushing, tapping,…) and with the patients’ volitation, this can often produce contraction of an inhibited muscle (only with intact peripheral nerve supply).• This effect can be used when muscle are inhibited postoperatively or in the later stages of regeneration of a mixed peripheral nerve
• These structures are fairly deep and it would take several minutes to produce a sufficiently low temperature to affect them.• As it was clinically demonstrated that the reduction of spasm and spasticity occurs within 30 seconds of ice application, the reaction to cooling can only be at the superficial tissues at the skin.• The skin stimulus produced by cold must have an effect on the general level of excitation and inhibition in the region of the anterior horn cells.• Once spasm and spasticity have been reduced, more long- time treatment is given in order to sustain the condition. In the case of spasm, active movements are used to break down the vicious circle of pain-spasm-more pain- more spasm.• With spasticity, the technique will depend upon the preference of the physical therapist.
Uses of Ice Therapy• Reduces pain.• Reduces spasticity.• Reduces muscle spasm.• Reduces swelling.• Promote repair of the damaged tissues.• Provide excitatory stimulus to inhibited muscles.• Used in strength training.
Reduction of Pain• Pain reduction is one of the major effects of ice application which has been used for many years.• The probable mechanism is that by the stimulation of cold receptors, impulses will be send back which will pass into the posterior root of the spinal cord. These impulses, arriving through large diameter nerves, effectively block out any other (pain) impulses attempting to access the spinal cord (pain gate theory).• This reduces the pain temporarily. For permanent pain relief, positive physiotherapy (strengthening, mobilization) has to be given during this period of transient pain relief.
Reduction of Spasticity• Spasticity is the pathological state of increased muscle tone resulting from damage to the upper motor neurons. The small anterior horn cell from the higher control of extrapyramidal system and fires spontaneously at an increased rate. The net result of this is ultimately to increase tone in the extrafusal muscle fibers, when the hypertonic spastic state appears.
• Spasm is a normal response to injury or pain and is manifested as an increase in muscle tone in a specific area with the apparent aim of limiting movement and further damage. However the amount of spasm is often exceeding and the sustained contraction of muscles will in turn start to produce pain, often resulting then in more spasm.
• The mechanisms by which cold reduces spasticity and spasm are probably:• the reduced velocity of nerve conduction.• the depressed sensitivity of receptors such as the muscle spindle.
Contraindications1. Impaired circulation (i.e., Raynaud’s phenomenon)2. Peripheral vascular disease3. Hypersensitivity to cold4. Skin anesthesia5. Open wounds or skin conditions (cold whirlpools and contrast baths)6. Infection
Possible effects are due to…..• The effects of cryotherapy seen are mainly due to• Reducution in muscle damage markers:• Creatine kinase• Lactate dehydrogenase• Myoglobin• Immune markers (leukocyte & neutrophils)• Reduce muscle soreness rating• Reduce muscle fatigue rating
Techniques of Application of Cryotherapy• The way which ice is applied will vary according to the required effects.• It may be applied in the following ways: – Ice towels – Ice packs – Immersion – Ice cube massage – Cold compression units – Ice spray – Contrast bath
Time of application of various tech.• The time required for the sequence varies, but several authors indicate cryotherapeutic effect sequences occurs within 5–20minutes.• After 12–15 minutes the hunting response is sometimes demonstrated with intense cold (10° C[50° F]). Thus, a minimum of 15 minutes are necessary to achieve extreme analgesic effects
Ice packs•Simple cold packs•Silica gel packs•Endothermicreaction /chemicalcold packs.
Ice towel•Wet towel is used•Ice towel need to bereplaced after 2-3 min.and total 20 min .oftreatment can begiven.•Useful in treatingmuscle and allowsmovement to beperformed.
Ice cube massage•Slow circular motion for 5-10 min. DuringThis time the patient will feel cold, burningAnd then aching sensation before the partBecome numb.•Short strokes should be given.
Cold compression unitCold water is circulated in a sleeve whichIs put over the limb and part of it is inflamedAt intervals.
Cold/ Ice sprays•Ethyl chloride was originally used butit is highly inflammable an thus possessome risks.•Fluorimethane is now used widely asit is non inflammable.• The liquid is sprayed on to the areato be cooled in series of stroke ofabout 5s each with a few secondsinterval between each.•The nozzle is held at the angle of 45or right angle from the skin surface.
CRYOTHERAPY IN SPORTS• ACUTE PHASE:• In acute phase of injury either on field or while exercise session the cryotherapy in form of either direct application of cold packs or cold spray is widely used.• Cryotherapy is given for atleast 72 hours from injury but it provides best results within 48 hours of injury or acute conditions.
Cryokinetics: Contraindications• Any exercise or activity that causes pain• Use of ice on a patient who is hypersensitive to cold
Cryokinetics: Precautions• Use pain as a guideline. – Warn patient not to gut out pain.• Don’t allow patient to limp.• May be an increase in pain 4–8 hr after treatment
Principles of Cryokinetics Exercise• All exercise should be active. • Performed by the patient• Exercise must be graded • Begin with range of motion exercises. • Progress through increasing levels of difficulty. • Full sport activity is final level.
Principles of Cryokinetics Exercise: Example (cont.)• Non-weight-bearing ROM – Plantar flexion – Dorsiflexion – Inversion – Eversion – Circumduction
Principles of Cryokinetics Exercise:Example (cont.) • Weight-bearing ROM – Stand up. – Shift weight from foot to foot. – Gradually increase weight on injured limb.
Cryostretch for muscle injuries• Most ( strains and contusions)result in muscle spasm or tightness.• Many mild muscle pulls are actually muscle in spasm rather than torn muscle fiber.• Reduce spasm with cryostretch.
Rehabilitation goal• Promote healing, if tissue torn.• Control pain• Reduce spasm• Control neural inhibition
Rehabilitation goals (cont.)• Reset central control through aggressive, progressive reorientation of full function.• Develop muscle strength.• Promote other phases of rehabilitation.
Cryostretch: Application Parameters • Three sets – Numb with ice then activity • Activity consists of two 65 sec bouts of exercise with 20 sec rest between bouts • 65 sec bout – Stretch muscle to limits and hold 20 sec – Three static stretches, interspersed with maximal isometric contraction (hold–relax)
Cryostretch: ApplicationParameters (cont.)• Numb muscle (20 min max)• 65 sec stretch–contraction• 20 sec rest• Repeat 65 sec stretch–contraction• Renumb• Two more stretching bouts (20 sec rest)• Renumb• Two more stretching bouts (20 sec rest)
Combined Cryostretch and Cryokinetics• Begin and end with stretch• Begin cryokinetics exercises with manually resisted muscle contractions (6-10) through a full ROM.• Use DAPRE technique for further progression.
Combined Cryostretch andCryokinetics (cont.)Progress through all phases of rehabilitation usingprogressive functional activities.
Dangers of cryotherapy• Frost bite• Nerve palsy
Severe Frostbite of the Knees After CryotherapyCharles K. Lee, MD; Jeff Pardun, MD; Rudolf Buntic, MD; Mark Kiehn, MD; Darrell Brooks, MD; Harry J. Buncke, MD Orthopedics January 2007 - Volume 30 · Issue 1:• A case report showing severe frost bite in 53 years old male, post op of patellar tendon Frostbite of the Feet After Cryotherapy: A Report of Two Cases William C. Brown, MD , David B. Hahn, MD
Cryotherapy and nerve palsy, David Drez, JR, MDDonald C. FaustJ. Pat Evans doi: 10.1177/036354658100900414• Ice application is one of the most extensively used treatments for athletic injuries. Frostbite is a recog nized danger. Five cases of nerve palsy resulting from ice application are reported here. These palsies were temporary. They usually resolve spontaneously with out any significant sequelae. This complication can be avoided by not using ice for more than 30 minutes and by guarding superficial nerves in the area.
Whole-body cryotherapy in athletes. Banfi G, Lombardi G, Colombini A, Melegati G. Sports Med. 2010 Jun 1;40(6):509-17• A peculiar form of cold therapy (or stimulation) was proposed 30 years ago for the treatment of rheumatic diseases. The therapy, called whole-body cryotherapy (WBC), consists of exposure to very cold air that is maintained at -110 degrees C to -140 degrees C in special temperature-controlled cryochambers, generally for 2 minutes• In sports medicine, WBC has gained wider acceptance as a method to improve recovery from muscle injury. Unfortunately, there are few papers concerning the application of the treatment on athletes• Widely recommended for the treatment of arthritis, fibromyalgia and ankylosing spondylitis.• The treatment does not enhance bone marrow production and could reduce the sport-induced haemolysis.
Bone remodelling biomarkers after whole body cryotherapy (WBC) in elite rugby players. Galliera E, Dogliotti G, Melegati G, Corsi Romanelli MM, Cabitza P, Banfi G. Injury. 2012 Sep 20. pii: S0020-1383(12)00368-3• Whole body cryotherapy (WBC) consists of a brief exposure to extreme cold air (-110°C) in a controlled chamber and it is applied in sports medicine to improve recovery from musculoskeletal trauma. The aim of this study is to better define the beneficial effect of WCB on the musculoskeletal system of athletes, in particular on bone remodelling. Remodelling osteoimmunological biomarkers OPG, RANKL and RANK were measured after WBC treatment in 10 male rugby players randomly selected from the Italian National team. OPG(osteoprotegeric) levels were increased significantly, supporting the view that WBC induces an osteogenic effect. Further studies evaluating the effect of WBC on bone metabolism are desirable.
Pre-cooling and sports performance: a meta-analytical review.Wegmann M, Faude O, Poppendieck W, Hecksteden A, Fröhlich M, Meyer T. Sports Med. 2012 Jul 1;42(7):545-64• Pre-cooling can effectively enhance endurance performance, particularly in hot environments, whereas sprint exercise is barely affected. In particular, well trained athletes may benefit in a typical competition setting with practical and relevant effects. With respect to feasibility, cold drinks, cooling packs and cooling vests can be regarded as best-practice methods.
Should athletes return to sport after applying ice? A systematic review of the effect of local cooling on functional performance. Bleakley CM, Costello JT, Glasgow PD. Sports Med. 2012 Jan 1;42(1):69-87• The current evidence base suggests that athletes will probably be at a performance disadvantage if they return to activity immediately after cooling. This is based on cooling for longer than 20 minutes, which may exceed the durations employed in some sporting environments. In addition, some of the reported changes were clinically small and may only be relevant in elite sport. Until better evidence is available, practitioners should use short cooling applications and/or undertake a progressive warm up prior to returning to play.
References• Clayton’s electrotherapy,9th edition- Sarah & Bazin- W.B Sunders.• John low &Reed: Electrotherapy Explained,Butterworth.• Lehman- therapeutic heat and cold; ch.14 application procedure.- William & Wilkins.• William E.Prentice: Therapeutic modalities in Sports Massage- Mosby.