Ultrasound/Laser/cryo (wk 3) Flashcards
What is ultrasound?
high frequency sound waves are transmitted through a wand or probe into the body and lead to vibrations of the molecules in the body
Expansion and compression of what in the ultrasound produces the sound waves?
Crystal
T/F The crystal creates a uniform intensity of the beam.
False, not perfectly uniform, and does not expand and contract uniformly leading to nonuniformity of intensity of the beam
How do you reduce the standing waves created by reflection of the ultrasound head?
Keep sound head moving
Where is absorption of ultrasound highest?
in tissues of greater density (lig/tendons)
What is attenuation of ultrasound energy?
measure of decrease in sound energy as the sound wave travels through different tissues
What frequency do you use if you are treating a superficial tendon or ligament?
3 MHZ = up to 2.5 cm deep
What frequency do you use when you are treating a deeper quad muscle?
1 MHz = up to 5 cm deep
What is the duty cycle of US?
– fraction of time the US energy is on over one pulse period (time on + time off)
What is the duty cycle for continuous US?
100%
What is the duty cycle for pulsed US?
20%, 50%, 100%
What are the proposed mechanism for use of US?
a. Modulate pain
b. Increase connective tissue extensibility
c. Reduce muscle spasm
d. Increase tissue temperature
e. Increase blood flow
f. Facilitate healing
Contraindication or precaution of US:
Impaired circulation
Contraindication
Contraindication or precaution of US:
impaired cognitive function
Contraindication
Contraindication or precaution of US:
breast implants
precaution
Contraindication or precaution of US:
absent sensation
Contraindication
Contraindication or precaution of US:
cancer
Contraindication
Contraindication or precaution of US:
healing fracture
precaution
Contraindication or precaution of US:
joint cement
Contraindication
Contraindication or precaution of US:
open epiphyseal plates (growth plates)
precaution
Contraindication or precaution of US:
directly over plastic components
Contraindication
Contraindication or precaution of US:
over vital areas (brain, eyes, heart, ear, reproductive organs)
Contraindication
Contraindication or precaution of US:
acute inflammation
precaution
Contraindication or precaution of US:
pregnancy
Contraindication
What is the goal of thermal (continuous) us?
Increasing tissue temperature through friction (aka vibration) between molecules (1-5cm depth dependent on frequency)
Proposed impacts of US? (5)
- Increased pain threshold
- Increased collagen extensibility
- Alteration of nerve conduction velocity
- Increased enzymatic activity
- Increased tissue perfusion
Excessively high temperatures may produce sudden strong ache caused by overheating of periosteal tissue causing what type of pain?
Periosteal pain - reduce intensity, increase treatment surface, add more coupling gel, or remove soundhead
Nonthermal (pulsed) US causes cavitation, what is that?
alternating compression and expansion of small gas bubbles in tissue fluids due to the mechanical pressure waves of the acoustic waves
Do we want stable or unstable cavitation?
we want stable cavitation
unstable cavitation - severe collapse of gas bubbles during compression phase of pulsed US which can results in local tissue damage due to high temperatures
Nonthermal (pulsed) US also causes acoustic streaming, what is that?
forward movement of fluid and ions along boundaries of cell membranes
If criteria for direct contact of US soundhead can not be safely met, what would you do?
immersion technique - for irregular surfaces, sensitive or broken integument
What 4 things do you document when doing intervention?
- Treatment area
- Patient position
- Parameters
- Outcome measure
If you have soft tissue shortening or pain, what parameters of US would you set? duty cycle? frequency? intensity? time?
thermal 100% duty 3 MHZ, 0.5-1.0 W/cm2 1 MHz, 1.5-2 W/cm2 5-10 min
If you have delayed tissue healing and prolonged inflammation, what parameters of US would you set? duty cycle? frequency? intensity? time?
non-thermal 20%,50% 3 MHz, 0.5-1.0 W/cm2 1 MHz, 1.5-2 W/cm2 5-10 min
The amount of laser light energy, light amplification by stimulated emission of radiation, absorbed by biological tissues depends on what?
the wavelength of light
If the laser power is greater than 500mW, what type of laser is it>?
High-intensity laser (hot laser)
Laser Physiological Effects?
- Improved mitochondrial function
- Promotes collagen production- through mRNA production
- Modulate inflammation- through Interleukin and Prostaglandin production
- Inhibit Bacterial growth of biological pathogens
- promotes vasodilation of microcirculation
- Increased nerve conduction velocities
What are the contraindications of laser?
a. Direct eye exposure
b. Pregnancy
c. Malignancy
d. Following acute injury where hemorrhage is possible or suspected
e. Open growth plates
f. Over the thyroid or other endocrine gland
What are some examples that research has shown laser to be weak-moderately beneficial in?
i. Carpal tunnel syndrome
ii. Reducing pain and muscle spasm in patients with fibromyalgia
iii. Myofascial/trigger point disorders
iv. Knee OA
v. Rheumatoid arthritis
vi. Migraine headaches
vii. Myofascial pain syndrome
viii. Tennis elbow
What is the heat/cold transfer from a one object to a another by direct physical contact; effective 1-3cm depth?
conduction
What is the heat/cold transfer by movement of air or fluid moving past a body part; affective 1-3cm depth?
convection
What is the heat/cold transfer from one object to another object by transmission of electromagnetic energy?
radiation
What are the goals of heat (thermo therapy)?
i. ↓ pain and stiffness
ii. Alleviate muscle spasm
iii. ↑ ROM and tissue extensibility
iv. Improve tissue healing by ↑ blood flow
Describe the increased physiological response to local heat on blood flow:
dilation of arteries/arterioles
Describe the increased physiological response to local heat on capillary permeability:
increased capillary pressure
Describe the increased physiological response to local heat on elasticity of nonelastic tissues:
increased extensibility of collagen tissue
Describe the increased physiological response to local heat on metabolism:
every 10 degree celsius increase in tissue temp = 2-3x increase cellular oxidation rate
Describe the increased physiological response to local heat on vasodilation:
release of vasoactive agents
Describe the increased physiological response to local heat on edema:
increase capillary permeability
Describe the decreased physiological response to superficial localized heat on joint stiffness:
increased tissue extensibility and dereased viscosity
Describe the decreased physiological response to superficial localized heat on muscle spasm:
decreased firing of muscle spindles and increased firing of GTO fibers reduces alpha motor neuron activity
Describe the decreased physiological response to superficial localized heat on pain:
inhibition of A delta and C fibers (gate control)
Contraindication or precaution of heat:
cardiac insufficiency
precaution
Contraindication or precaution of heat:
edema
precaution
Contraindication or precaution of heat:
acute inflammatory conditions
Contraindication
Contraindication or precaution of heat:
decreased sensation
precaution
Contraindication or precaution of heat:
absent sensation
Contraindication
Contraindication or precaution of heat:
DVT
Contraindication
Contraindication or precaution of heat:
decreased mentation
precaution
Contraindication or precaution of heat:
impaired circulation
precaution
Contraindication or precaution of heat:
malignant tumor in area of application
Contraindication
Contraindication or precaution of heat:
impaired thermal regulation
precaution
Contraindication or precaution of heat:
impaired cognitive function
Contraindication
Contraindication or precaution of heat:
metal in treatment area
precaution
Contraindication or precaution of heat:
open wounds
precaution
Contraindication or precaution of heat:
tendency toward hemorrhage
Contraindication
Contraindication or precaution of heat:
demyelinated nerves
precaution
What is the method of moist hot packs?
Must be wrapped in how many layers?
conduction
6-8 layers
Always do what 3 things before applying moist hot pack to patient?
- Educate patient on what to expect
- Provide a means of alerting therapist
- Inspect skin prior to tx, after 5 minutes, and following treatment
Precautions when using a moist hot pack?
Weight of MHP, position of patient, if patient falls asleep
What is the method of a paraffin bath?
Useful treatment on what size joints?
conduction (wax dip)
small joints
What is the method of a whirlpool?
Treatment time?
Conduction
20 min
Precautions of using whirlpool?
decreased sensation, decreased cognition, recent skin graft
Contraindication of using whirlpool?
open wound
What are the goals of cryotherapy (cold)?
i. ↓ pain
ii. Reduce inflammation or swelling
iii. Alleviate muscle spasm
iv. Reduce spasticity
v. Management in multiple sclerosis (adverse response to heat)
vi. Cryostretch (apply cold, get it numb, static stretch)
Why is cryotherapy used in acute trauma?
- Vasoconstriction and decreased fluid filtration into interstitial tissue
- Decreased metabolism and vasoactive agents=decreased inflammation and edema
- Increases pain threshold
How does cryotherapy decrease muscle spasms?
- Decreased firing of muscle spindle, increased firing of GTO
How does cryotherapy decrease pain threshold?
gate control theory
T/F Cryotherapy increase muscle strength
True, short lived 1-5 minutes after application
Describe a adverse effect of histamine reaction to small area of cold application: (describe cold urticarial)
- Facial flush, puffiness eyelids, respiratory problems, in severe cases anaphylaxis (decreased blood pressure, increased heart rate) with syncope
- Cold urticarial: erythema of the skin with wheal formation (raised bumps) associated with severe itching due to histamine reaction
Contraindication or precaution of cryotherapy: cold hypersensitivity (urticarial)
Contraindication
Contraindication or precaution of cryotherapy:
cold intolerance
Contraindication
Contraindication or precaution of cryotherapy:
HTN
precaution
Contraindication or precaution of cryotherapy:
cryoglobulinemia
Contraindication
Contraindication or precaution of cryotherapy:
peripheral vascular disease
Contraindication
Contraindication or precaution of cryotherapy:
severe impaired temperature sensation
Contraindication
Contraindication or precaution of cryotherapy:
impaired temperature sensation
precaution
Contraindication or precaution of cryotherapy:
Raynaud’s disease
Contraindication
Contraindication or precaution of cryotherapy:
open wound
precaution
Contraindication or precaution of cryotherapy:
over superficial nerve
precaution
Contraindication or precaution of cryotherapy:
paroxysmal cold hemoglobinuria
Contraindication
Contraindication or precaution of cryotherapy:
over regenerating peripheral nerves
Contraindication
Contraindication or precaution of cryotherapy:
cognitive changes
precaution
What are general considerations for cryotherapy?
- accessibility
- body part
- if compression and elevation required
- size of area
- time since injury
- hypersensitivity
7 contraindications/precautions - passive (activity lessens effects)
Duration of cryotherapy? ice massage?
10–30 minutes (longer if casts/bandages)
ice massage can be shorter
Post-treatment precautions of cryotherapy?
Avoid excess stresses to area 1–2 hours post-treatment
What is method of ice massage? Continue until what occurs?
conduction
until anesthesia achieved generally 5-10 minutes (describe to patient steps before numbness so they know what to expect)
What do you describe to the patient that they will feel before using ice massage?
cold, burning, aching, numbness
What is the method of vapocoolant? What is the goal?
Evaporation
goal - Generally used to reduce muscle spasm and/or desensitize trigger points
T/F when using vapocoolant you want to frost skin.
FALSE
What are the next two steps after applying vapocoolant?
- Passively stretch after application ->apply moist heat
2. Have patient perform active exercise after application of moist heat
What is the method of contrast bath? What is the goal?
Conduction
goal - produce vascular exercise through active vasodilation and vasoconstriction of blood vessels; may help with pain modulation
What are the indications for contrast bath usage?
any condition requiring peripheral circulation stimulation, sprains, strains
General treatment preparation for thermo and cryotherapy:
- Treatment and expected sensations must be explained to patient
- Expose treatment area; drape properly
- Leave call bell or signaling device with patient to alert PT of any adverse response
- Check patient frequently especially during initial treatment
- Dry and inspect skin at conclusion
- Record response
What is shortwave diathermy?
Electromagnetic energy produces deep heat within tissues (5cm)
What are the two types of short wave diathermy?
- Continuous - increases temperature in deeper structures
2. Pulsed - allows dissipation of heat during the off cycle and can result in other physiological/therapeutic benefits
Continuous (thermal) short wave diathermy physiological effects:
- Increased temperature to deep & superficial tissues
- Increased soft tissue extensibility
- Increased nerve conduction
- Vasodilation
What are the indications and goals of continuous (thermal) short wave diathermy?
- Increased joint ROM
- Pain management
- Increased tissue healing
Pulsed (nonthermal) short wave diathermy physiological effects:
a. Increased microvascular perfusion
b. Increased local tissue oxygenation
c. Increased cell growth and phagocytosis
d. May help healing of wounds and diabetic ulcers
What are the indications and goals of pulsed (nonthermal) short wave diathermy?
a. Pain control
b. Decrease edema
c. Resolution of acute and chronic infections
d. Wound control and soft tissue healing
What are 2 contraindications of short wave diathermy?
- Pregnancy (therapist or patient)
2. Implanted neural or cardiac stimulators
What are specific contraindications of continuous (thermal) short wave diathermy?
open epiphyses, metal implants and jewelry, malignancy, near the testes or eyes
What are specific contraindications of pulsed (nonthermal) short wave diathermy?
over diseased internal organs, over metal loops that secure plates or rods
What are 2 precautions of short wave diathermy?
- Use of equipment near electronics or magnetic equipment
2. Patients or nearby personal with metal bearing intrauterine devices
What is short wave Diathermy: the Capacitive Method?
electric field method
- The body part being treated is placed between two electrically charged plates
- Patient becomes part of the circuit. High frequency alternating current flows from one plate to the other through the patient
- Charged particles oscillate and tissue temperature increases
What position are plates in for contraplanar short wave Diathermy: the Capacitive Method?
Plates positioned on each side of the body part.
What position are plates in for coplanar short wave Diathermy: the Capacitive Method?
Parallel to on the same body surface
What is short wave diathermy the inductive method?
- Magnetic field method
alternating current in a coil produces a magnetic field which creates an oscillating magnetic field (“eddy” current); vibration causes temperature to rise in tissue
What determines the degree of heat generation for short wave diathermy the inductive method?
- strength of magnetic field
- distance applicators
- conductivity of the tissue
Collagen, fat, and bone have what level of conductivity of short wave diathermy the inductive method?
low conductivity
Muscle, synovial tissue have what level of conductivity of short wave diathermy the inductive method?
high conductivity