heat and cold Flashcards
PHYSICS FUNDAMENTAL - wax and heat pack
Heat flows from hot objects to colder objects
PHYSICS EXPLAINED - hot pack
takes 30 - 2hrs for back to be heated
Pack temp falls but skin /superficial tissue
temp rises as heat flows from pack to
body
‣ Layering of towels provides thermal
insulation, decreasing heat conduction,
allowing the hot pack to stay hot longer
and slowing heat transfer making it safer
‣ Due to insulation, it will take ~ 8 mins for
skin temp to reach max.
The hot pack is ~ 70 °C, and skin temp doesn’t rise above ~ 42°C
‣ Towels / pack prevent skin from losing
heat to surroundings
PHYSIOLOGICAL EFFECTS - wax and hot pack
‣ Speeds up healing process ‣ Increases metabolic activity ‣ Decreases fluid viscosity ‣ Vasodilation ‣ Increases fluid exchange across capillary walls ‣ Increases collagen extensibility ‣ Relieves pain ‣ Reduces muscle spasm
- wax = Used to provide heat treatment to areas of
non-uniform surfaces i.e. hands
physio aim
Warm target tissue to increase blood flow and
metabolic rate
cool target tissue to decrease blood flow and mr
CONTRAINDICATIONS - heat
circulatory insufficiency - PVD Exacerbation of existing conditions - tumours, Risk of dissemination - skin conditions To eyes or testes * CHECK OPEN WOUNDS FOR WAX
PRECAUTIONS - heat
Sensory loss (thermal or anaesthetic) unable to communicate
INDICATIONS - heat
‣ Tissue healing (sub-acute to chronic inflammatory phases) ‣ Relief of pain (most common use) ‣ Reduction of muscle spasm ‣ Sedative effect ‣ Increase joint ROM ‣ Prophylaxis of pressure sores ‣ Chronic oedema ‣ Precursor to other treatment (eg. stretching, joint mobilisation, massage)
KEY POINTS - heat
‣ Generally avoided in acute phase due to potential for increased bleeding ‣ Typical clinical uses include: ‣ subacute to chronic musculoskeletal conditions (eg OA) ‣ following extended immobilisation (eg fracture) ‣ prior to other treatment
Describe the 3 main indications for using conductive
heating therapeutically.
Promotion of soft tissue healing.
Decrease pain and promote muscle relaxation
Reduce joint stiffness
physics of ice
Heat flows from hot to cold bodies ‣ With an ice pack, the hot and inflamed tissue cools down as heat flows into the ice pack from the tissue ‣ A system (ice pack + body) always tends to thermal equilibrium where heat flows between the objects in the system until they are at the same temperature ‣ Extent of temperature changes in the tissues depends on the rate and amount of heat energy removed. This energy is used in heating and melting the ice pack ‣ Heat conducts away faster with: - bigger temperature difference - ie. really cold ice/gel pack - greater area of contact between hot and cold regions - smaller distance between hot and cold regions - fewer layers of materials in between eg skinnier person
5 - 15 MINS
WHILST HEAT IS 15-20
PHYSIOLOGICAL EFFECT - ice
‣ A decrease in tissue temperature: 1. Decreases local blood flow ‣ SKIN: initial vasoconstriction of cutaneous vessels, then after 5-10 mins vasodilation occurs (hunter reaction) ‣ MUSCLES: vasoconstriction after 5-8 mins for superficial structures, >10mins for deeper 2. Decreases metabolic rate: enhances the survival of local cells as they demand l e s s o x y g e n a n d s l o w s d o w n inflammation 3. Affects peripheral nervous system: slows conduction velocity and can release endorphins and enkephalins 4. Relieves pain, relaxes muscles, and reduces muscle strength, coordination and motor skills when applied >30 mins 5. Stimulates and facilitates muscle activation when applied <10 mins.
CONTRAINDICATIONS
Circulatory Insufficiency Exacerbation of existing conditions Cold sensitivity Cryoglobinaemia - blood proteins become insoluble at lower temps Cold urticaria (cold allergy)
PRECAUTIONS
Sensory loss (thermal or anaesthetic)
Unable to communicate
Emotional/ psychological features
INDICATIONS ICE
Cold treatment to reduce pain and swelling Therapeutic uses include: ‣ acute soft tissue injuries ‣ acute inflammatory joint effusion ‣ post surgery ‣ muscle spasm reduction due to pain relief ‣ muscle spasticity ‣ muscle strengthening ‣ chronic inflammation ‣ oedema ‣ joint effusion Other uses include ice massage for pressure sores, and ice with stretching (in conjunction with trigger point therapy)
WARNINGS
ICE: feel gradually increasing cold,
which may be followed by a
period of discomfort. The area should then go numb.
