Physical Agents ch. 15,16,17,19

True or False: Frequency and wavelength are inversely proportional

True

Low frequency electromagnetic radiation

-shortwaves
-microwaves
-IR radiation
-visible light
-uv light

Low Frequency EMR is...

Non-ionizing

High Frequency electromagnetic radiation

-x-rays
-gamma rays

High frequency EMR is...

Ionizing

Intensity of EMR is greatest when...

-energy output is HIGH
-source CLOSE to pt.
-beam is PERPENDICULAR

Clinical Effects of EMR are determined by...

radiation's frequency and wavelength range

Inrared (IR)

produced superficial heating w/o requiring direct contact

Visible Light

sunlight is the earliest form of EMR

UV radiation

produces erythema, tanning of skin, Vitamin D synthesis

Shortwave & micromwave energy

heat deep tissues; decreases pain, edema, facilitate tissue healing by non-thermal mechanisms

low-intensity laser & light

visible & near IR frequency ranges
-promote tissue healing, control pain & inflammation by non-thermal mechanisms

Physiological Effects of EMR

-can be thermal or non-thermal
-continuous = thermal (deep tissue)
-pulsed = non-thermal
-IR lamps used to heat superficial tissue

Non-thermal mechanisms of EMR

cause changes at a cellular level by altering...
-cell membrane function
-permeability
-intracellular function
promotes binding of chemicals

Non-thermal mechanisms of EMR accelerate synthesis and use of what?

ATP (energy molecule)

Arndt-Schulz Law

used to explain effects of law, non-thermal levels of EMR
-there is a certain min. stim. is needed to initiate a biological process
-Too much is bad

LASER

-monochromatic
-coherent
-directional

Monochromatic

(of light or other electromagnetic radiation) having only one wavelength

coherent

symmetrical wave

Divergent

Going in different directions

High intensity ("hot" laser)

used in surgery because
-sterile beam
-fine control
-cauterizes as it cuts
-produces less scarring

Types of Diodes

-LED (light emitting diode)
-SLD
-Laser Diode

SLD

-high intensity
-almost monochromatic
-Medium coherence
-Medium directionality
-Medium tx area/shorter application times

LED (one color)

-low intensity
-Not monochromatic
-Low coherence
-Low directionality
-large tx area

Laser Diodes

-High intensity
-Is monochromatic
-High coherence
-High directionality
-small tx area

Wavelength of Laser and Light

light w/longer wavelength (lower frequency) penetrates more deeply

Between ____ - ____ nm optimal depths of penetration in human tissue

600-1300 (red or IR)

IR penetrates ______ cm into soft tissue

2-4

Red light penetrates a few ____

mm

Power density of laser

mW/cm2

Most laser diodes used for therapy have a power of __mW

5-500

Laser effectiveness is greatest with...

-short-duration
-high power doses

Energy is measured in _____

Joules

Energy (J) =

Power (W) x Time (s)

Effects of Laser and Lights

-promotes ATP production
-promotes collagen production
-Modulate inflammation
-Inhibit Bacterial Growth
-Promote Vasodilation
-Alter Nerve Conduction Velocity and regeneration

Red laser and mitochondrial funtion and increase production of ATP by ____%

70

Clinical Indications for Laser & Light

-tissue healing (soft tissue and bone)
-Arthritis
-Lymphedema
-Neurological Conditions
-Pain management

Parameters for tissue healing w/laser and light

Red or IR @ 5-24 J/cm2

Arthritis w/laser and light

-increase grip strength and flexibility
-decrease swelling and pain
-improved function for cervial OA

Contraindications for Laser/light

-contact w/ eyes
-malignancy
-w/i 4-6 months after radiotherapy
-over hemorrhaging regions
-over thyroid or endocrine glands

Precautions for laser/light

-pregnancy
-epiphyseal plates (children)
-impaired senstation
-impaired memtaion
-photophobia (high sensitivity to light)

Adverse Effects of lasersq

-burning
-skin rash
-eye irritation

Documentation of laser use

-type of diode
-wavelength
-power
-area of body
-energy density

UVA (long wave)

produces fluorrescence in many substances

UVB (middle wave)

produces the most skin erythema

UVC (short wave)

germicidial
-filtered out by ozone

UV

produces non-thermal physiological effects

Intensity of UV reaching skin is highest when

-close to skin
-beam perpendicular to skin

Physiological Effects

-Vitamin D synthesis (helps w/bone formation)
-skin erythema (redness of skin)
-UVC is bacterial (wound care)

Vitamin D is good b/c...

-decreases BP
-improve blood glucose levels
-improves symptoms in MS and RA

Clinical Indications for UV

skin disorders
-Psoriasis
-acne
-scleroderma
-eczema

Contraindications for UV

-irradiation of the eyes
-skin cancer
-pulmonary tuberculosis
-cardiac, kidney, or liver
-lupus
-fever

Precautions for UV

-photosensitivity
-recent x-ray therapy

Adverse Effects of UV

-burning
-carciongenesis
-eye damage

Dose-Response Assessment

the process of characterizing the relationship between the dose of an agent administered or received and the incidence of an adverse health effect

Categories of Dose-Response Assessment

-suberythemal dose
-min. erythemal dose
-1st degree erythema
-2nd degree erythema
-3rd degree erythema

Documentation of UV

-if and how psoralen was given
-area of body
-type of UV
-Serial # of lamp
-distance b/w lamp and pt.
-tx duration
-response to tx

Thermal Conductivity

The ability of an object to transfer heat

Buoyancy

Ability to float

Resistance

The viscosity of water provides resistance to motion of the body in water

Hydrostatic pressure

Pressure exerted by a volume of fluid against a wall, membrane, or some other structure that encloses the fluid.

Physiological Effects of Hydrotherapy

-cleansing
-musculoskeletal
-cardiovascular
-respiratory
-renal
-psychological

Cleansing effects of hydrotherapy

-hydrating effects and friction of water to soften and remove foreign objects

Musculoskeletal effects of hydrotherapy

-unloads WB anatomical structures and can allow pt.s with load-sensitive joint
-pt.s with arthritis and obesity

Cardiovascular effects of hydrotherapy

-increases venous circulation
-increased cardiac output
-decreased HR & systolic BP asa respond to exercise

Use RPE (Borg) during hydrotherapy b/c ...

target hydrostatic pressure

Respiratory effects of hydrotherapy

-full body immersion increases work of breathing
-used to improve resp. strength
-water based exercises are often recommended for pt.s w/asthma

Renal effects of hydrotherapy

-effects can be taken advantage of in the tx of pts with hypervolemia, hypertension, peripheral edema

Uses of Hydrotherapy

-superficial heating/cooling
-water exercise
-pain control
-edema control
-wound care

Pros of heating/cooling w/hydrotherapy

-perfect contact
-doesn't need to be fastened
-allows for movement

Cons for heating/cooling w/hydrotherapy

-distal limbs are in a dependent position (may aggravate edema)

Hydrotherapy and Pregnancy

-thought to pose less risk to fetus than land-based exercise

Whirlpool

only used for cleansing wounds that contain
-necrotic tissue
-gross purulence
-dry eschar

Contraindications for Full Immersion

-cardiac instability
-infections
-bowel incontinence
-severe epilepsy
-suicidal pts

Precautions for Full Immersion

-pregnancy
-MS
-Poor thermal regulation
-urinary incontinence
-respiratory problems

Advantages of Contrast baths

-promote vigorous circulatory effect

V.A.C.

-used w/
-pressure ulcers
-diabetic foot wound
-large surgical wounds

Effects of Compression

-Improvement of venous and lymphatic circulation
-limits shape and size of tissue
-increase tissue temp.

Compression

A force that pushes on or squeezes a material.

_______ compression is more effective "milking" than single chamber intermittent compression

sequential

Clinical Indications for Compression

-Edema
-DVT
-Venous stasis ulcer
-Residual limb shaping after amputation
-control hypertrophic scarring (burn healing)

Lymphedema

Abnormal collection of fluid in tissue spaces caused by obstruction of lymph vessels and backflow of lymph.

Causes of Edema

-airline travel
-pregnancy
-other medical conditions
-phlebitis
-function of valves

static compression

utilizes bandaging and garments

intermittent compression

With a pneumatic device is primairly used t reduce chronic or post-traumatic edema and requires adjusting the parameters of inflation pressure, on/off ratio, and the total treatment time.

Contraindications for Compression

-heart failure
-acute DVT
-pulmonary embolus
-acute skin infection
-Peripheral artery disease (PAD)

Precautions for Compression

-impaired sensation
-uncontrolled hypertension
-cancer
-stroke
-superficial periph. nerves

resting pressure

elastic bandage exerts pressure whether pt is moving or immobile

working pressure

produced by active muscles pushing against inelastic bandages only when pt. is moving