This lecture intends to provide general outline about the uses, parameters, precautions and contraindications of therapeutic ultrasound for undergraduate physiotherapy students at Kathmandu University School of Medical Sciences, Nepal. After the lecture, students will explore the evidences about current practices of therapeutic ultrasound in various musculoskeletal pain conditions, critically appraise them and present the evidences to the class.
Bulimia nervosa ( Eating Disorders) Mental Health Nursing.
Therapeutic Ultrasound for Physiotherapy students
1. Saurab Sharma, MPT
Lecturer, KUSMS
Therapeutic Ultrasound (US)
MSK III b – Cervical and thoracic
Spine
Electrotherapy
Lecture 4
2. Objectives of session
At the end of the class, students will be
able to:
Understand the background of ultrasound
Explain the transmission, penetration and
absorption of ultrasound
Explain the effects of ultrasound
Identify the uses of Ultrasound
Explain the application of ultrasound
Identify Precautions and Contraindications
2
3. Introduction
Most common modality used- 94% (Pope
et al, 1995)
Initially used for thermal effects, now
used for its non-thermal effects
3
4. Ultrasound Transmission
Does not pass through air (greatest
steal- air impedance)
Presence of air between skin and
ultrasound head, means probability of
reflection- 99.9%
Coupling medium required- water, gel,
oil, cream
Head position- 90 degrees to skin4
5. Penetration and absorption
Greater absorption in superficial tissue
than deep
Half value depth-
Different for different tissues and
frequencies
3 MHz- 2 cm
1 MHz- 4 cm
Tissue with high protein absorbs more
US
5
7. Effects: Thermal
Absorbed US generates heat. It
depends on:
Nature of the tissue: high for protein
Degree of vascularization
Frequency of US: more frequency more
absorption
Insufficient to raise temperature to cause
therapeutic changes
7
8. Effects: Thermal
Should reduce pain, increase local blood
flow, decrease joint stiffness
Biologically significant thermal effect can
be achieved by increasing the tissue
temperature to 40 – 45 degrees for at least
5 minutes.
8
10. Effects: Tissue Repair
Three phases of repair process
1. Inflammation
2. Proliferation/ granulation tissue
formation
3. Remodeling
Effect of US depends on the phase in
which it is used
10
11. Effects: Tissue Repair:
Phase 1: Inflammation
Acoustic streaming forces produces
changes in permeability of platelets
membrane causing release of serotonin.
Serotonin may influence release of other
factors.
Platelets also contain wound factors
essential for successful repair.
11
12. Effects: Tissue Repair:
Phase 1: Inflammation
Single dose of US given soon after
injury can stimulate mast cells to release
histamine.
Changes in permeability of mast cell to
calcium ion, potassium ions etc.
Calcium ions act as intracellular signal
for appropriate metabolic response.
12
13. Effects: Tissue Repair:
Phase 1: Inflammation
Cavitation is the physical mechanism
responsible
Cavitation is the likely to occur at lower
frequency, whereas higher frequency
causes heating
US causes edema to form and resolve
more rapidly accelerating healing process.
13
14. Effects: Tissue Repair
Phase 2: Proliferative phase of
repair
US may maximize cell proliferation,
causes migration of cells
US accelerates the rate of angiogenesis
Continuous mode- 0.5 w/cm2- 20%
increase in collagen
Pulse US- 0.5 w/cm2- 30% increase in
collagen
14
15. Effects: Tissue Repair
Phase 2: Proliferative phase of
repair
Wound contraction is accelerated by US
Pulsed- 3 MHz, 0.5 w/cm2
Same degree of contraction can be
achieved by 0.1 w/cm2
15
16. Effects: Tissue Repair
Phase 3: Remodeling phase of
repair
US changes the types of collagen from
type III to type I
Increases tensile strength
Increase scar mobility
Enhances functional capacity of scar
tissues
16
17. Effects: Tissue Repair
Phase 3: Remodeling phase of
repair
Best results- when if treated immediately
after injury: 0.1w/cm2 for 3 times/week for 2
weeks causes increased tensile strength
and elasticity
Increases amount of collagen deposits
Improves the pattern of deposition like
normal tissue
Lower intensities are better than higher
17
18. Application of Ultrasound:
Factors to be considered:
Choice of machine
Calibration
Choice of coupling medium
Frequency
Intensity
Mode
Duration of treatment
Hazards18
19. Application of Ultrasound:
Factors to be considered:
Choice of machine
Calibration
Choice of coupling medium
Frequency
Intensity
Mode
Duration of treatment
Hazards19
21. Application of Ultrasound:
Factors to be considered:
Choice of machine
Calibration
Choice of coupling medium
Frequency
Intensity
Mode
Duration of treatment
Hazards21
22. Application of Ultrasound:
Factors to be considered:
Choice of machine
Calibration
Choice of coupling medium
Frequency
Intensity
Mode
Duration of treatment
Hazards22
23. Application of Ultrasound:
Factors to be considered:
Choice of machine
Calibration
Choice of coupling medium
Frequency : 1 MHz vs 3 MHz
Intensity
Mode
Duration of treatment
Hazards23
24. Application of Ultrasound:
Factors to be considered:
Choice of machine
Calibration
Choice of coupling medium
Frequency
Intensity: Less vs more
Mode
Duration of treatment
Hazards24
25. Application of Ultrasound:
Factors to be considered:
Choice of machine
Calibration
Choice of coupling medium
Frequency
Intensity
Mode: Pulsed vs continuous
Duration of treatment
Hazards25
26. Application of Ultrasound:
Factors to be considered:
Choice of machine
Calibration
Choice of coupling medium
Frequency
Intensity
Mode
Duration of treatment
Hazards26
27. Application of Ultrasound:
Factors to be considered:
Choice of machine
Calibration
Choice of coupling medium
Frequency
Intensity
Mode
Duration of treatment
Hazards27
30. Contraindications, dangers,
precautions
Consider general contraindications to
Electrotherapy
Spread of infection to the tissue
70% alcohol swab reduces infection significantly
Use it on every patient every time
Pregnancy- avoid lower thorax, trunk and
pelvic region
Malignant tissue
Active epiphysis
Higher dose US is avoided at fracture sites
30
32. Objectives of session
At the end of the class, students will be
able to:
Understand the background of ultrasound
Explain the Production, transmission,
penetration and absorption of ultrasound
Explain the effects of ultrasound
Identify the uses/ Indications of Ultrasound
Explain the application of ultrasound
Identify Precautions and Contraindications
32
33. References
Kathleen Sluka. Mechanism and Management
of Pain for the Physical Therapist. 2nd Edition.
IASP Press. Wolters and Kluwer. 2016
Tim Watson. Electrotherapy: Evidence Based
Practice. 2008. Churchill Livingstone. 12th
edition.
John Low, Ann Reed. Electrotherapy
Explained. Principles and Practice.
Butterworth Heinemann. 3rd Edition.33
Notas del editor
For maximum transmission of energy, impedence two medium needs to be same.
For maximum transmission of energy, impedence two medium needs to be same.
Half value depth- is the depth in the tissues at which half the surface energy is available. Blood and fat has more water and less protein so absorbs least
For maximum transmission of energy, impedence two medium needs to be same.
Biologically significant thermal effect can be achieved by increasing the tissue temp to 40 – 45 degrees for at least 5 minutes.
Biologically significant thermal effect can be achieved by increasing the tissue temp to 40 – 45 degrees for at least 5 minutes.
Histamine is one of the major chemicals that modifies the wound environment at this time after injury.
Histamine is one of the major chemicals that modifies the wound environment at this time after injury.
Histamine is one of the major chemicals that modifies the wound environment at this time after injury.
Type III to type I
Type III to type I
Less intensity for wound healing; more than 1.5 w/cm2 may had adverse events on healing tissues
Acute- less than 0.5; chronic less than 1 (0.3- 0.8)
Less intensity for wound healing; more than 1.5 w/cm2 may had adverse events on healing tissues
Acute- less than 0.5; chronic less than 1 (0.3- 0.8)
Less intensity for wound healing; more than 1.5 w/cm2 may had adverse events on healing tissues
Acute- less than 0.5; chronic less than 1 (0.3- 0.8)
Less intensity for wound healing; more than 1.5 w/cm2 may had adverse events on healing tissues
Acute- less than 0.5; chronic less than 1 (0.3- 0.8)
Less intensity for wound healing; more than 1.5 w/cm2 may had adverse events on healing tissues
Acute- less than 0.5; chronic less than 1 (0.3- 0.8)
Less intensity for wound healing; more than 1.5 w/cm2 may had adverse events on healing tissues
Acute- less than 0.5; chronic less than 1 (0.3- 0.8)
Less intensity for wound healing; more than 1.5 w/cm2 may had adverse events on healing tissues
Acute- less than 0.5; chronic less than 1 (0.3- 0.8)
No evidence of harm in pregnancy, avoid to be at safer side
No evidence of harm in pregnancy, avoid to be at safer side