Therapeutic application of cold. Best use is in 48 hours following injury. The cold affects he inflammatory response that occurs after a soft tissue injury by reducing enzymatic and metabolic function.
Evidence on outcomes:
Bleakley et al - systematic review of RCT’s- cryotherapy better than heat in acute ankle injuries
Effects of cold on tissues:
Vasoconstriction (initially*; acts directly on skin cold receptors --. contraction of vascular smooth muscles; also decreases production of vasodilator mediators); pain decrease (may work through gate control theory from stimulation of skin cold receptors or interruption of muscle spasm); decreased muscle spasm (lower activation level for muscle spindle); decreased vascular permeability; reduced swelling; decreased metabolism (decreases rates of all reactions associated with inflammation and healing reason not to use after acute phase is over; decreased metabolic rate decreases demand for oxygen and helps limit further tissue damage); decreased number of leucocytes and phagocytes; decreased lymphatic and venous drainage; decreased nerve conduction velocity (occurs after 5 mins, lasting for up to 20 mins; greater effects on myelinated and small nerve fibres).
*Cold induced vasodilation (CID) is likely to occur after 15 minutes of cold application, however this does tend to be inconsistent - called ‘Hunting effect’.
Decreases in temperature have been recorded as deep as high as 20 degrees at the skin and by 4 degrees at a depth 4cm with use of ice (depth of penetration may be dependent on amount of subcutaneous tissue and length of application).
Earliest sign of tissue damage from cold (ie frostbite) start at tissue temperatures of 3-10 degrees)
Mechanisms of cold transfer to tissues:
1) Convection – by air movement over skin (not used)
2) Evaporation – substance is applied to skin thermal energy used to evaporate cooling (eg vapocoolant sprays)
3) Conduction – cold object in contact with part to be cooled (eg ice packs) – heat transfers from the body part to the object – most commonly used method
Methods of application:
Ice cube; crushed ice in towel or plastic bag; frozen gel packs; cold sprays for more superficial cooling (eg fluoromethane); immersion in iced water or cold whirlpool; ice massage (massage area with ice cube); cyrokinetics (combination of cold and exercise); controlled cold compression units
Usually applied for 10 – 15 minutes.
Freeze water in small paper or Styrofoam cups peel back to edge of cup, hold base ice massage over injured area
Mechanical trauma; acute soft tissue injury; control inflammation; muscle spasm; swelling reduction; pain relief
Control of acute inflammation accelerate recovery from injury (needs to be applied early following injury to control bleeding into tissues and swelling).
Impaired circulation; cold hypersensitivity or cold induced urticaria; cold intolerance; Raynauds phenomenon; acrocyanosis; rheumatoid arthritis; collagen diseases; hypertension; cryoglobulinaemia; open wounds
Use with caution – over superficial nerves; open wounds; sensory neuropathy; poor local circulation
Exercise while ice being applied