Non Thermal Agents Flashcards
What happens to therapeutic ultrasound applied at low frequencies
Greater penetration resulting in greater availability of energy for absorption in deeper tissue
What factors impact how tissues absorb energy
Tissues with higher protein (absorb more)
Thus tissues with greater capacity to absorb energy will respond more effectively
Which structures have the best absorption
Tendon Ligament Fascia Joint capsule Scar tissue
Therapeutic benefits to ultrasound
Enhance recovery
Reduce pain in chronic musculoskeletal complaints
Promote physical function
Short term increase in soft tissue extensibility and improve mobility
Promote wound healing
Promote fracture healing when at low intensity
What is cavitation
Formation of gas filed voids within tissues and body fluids
Gas bubbles accumulate
Enhance acoustic streaming
Explain acoustic streaming
Eddying fluids near vibrating structures
Effects : diffusion rate + cell membr permeability
Na+ ion permeability altered = cell membr permeability altered
Ca ion transport modified= alters metabolic process
Acoustic streaming + stable cavitation =. ⬆️excitability of cell
Physiological effects of ultrasound during inflammatory phase
Pro-inflammatory
Stimulates: platelets / macrophages / phagocytes
Stimulates inflammatory mediators
Pre-curser to proliferative phase
Physiological effects of ultrasound during proliferative phase
Pro-proliferative
Stimulates : fibroblast / myofibroblast / endothelial cells
⬆️ protein synthesis/ collagen synthesis
Physiological effects of ultrasound in remodelling phase
Promote re-orientation of collagen fibres
Stimulate collagen profile change
Pre-cautions of ulttrasound
- use lowest intesity to promote benefits
- constant movement of treatment head
Avoid ultrasound in following cases
Directly over uterus in pregnancy Over malignant tissue Bleeding / haemorrhage Deep vein thrombosis Emboli Arterosclerosis Ver metal implants
Where not to apply ultrasound
Eye
Cardiac pt with pacemaker
Sympathetic nerve @ C6/7
Genitals
Name the 4 dosage parameters
Frequency: MHz——> determined according to tissue depth
Intensity: W/cm2 ———> determined according to stage of healing
Duty cycle: % or rate ——> determined according to stage of healing
Time———> determined with pulse duration
Size of treatment area
3 stages of healing
1) acute phase
0.1-0.3 W/cm2 (intensity)
20; 25% (duty cycle)
2) sub acute phase:
0.2-0.5 w/cm2 (intensity)
25;33; 50% (duty cycle )
3)Chronic phase:
0.3-0.8 w/cm2
33; 50 ; 100%
Frequency for ultrasound according to depth of tissue
Superficial- ⬆️ Fr (3)
deep tissue-⬇️ fr (1)
