Physical Agents Biofeedback, UV, and lasers

biofeedback

A technique which provides information to the user about their own physiological or biomechanical processes as a means of improving self-awareness and control of a specific, targeted process

enhance

biofeedback is used to facilitate a user's ability to self regulate a targeted biological process to ____ performance or as a part of a comprehensive treatment plan for a specific medial condition

control

biofeedback requires a user to learn how to _____ a targeted process using attentional strategies to create a therapeutic or performance effect

direct biofeedback

produces an accurate external representation of the internal biological process

- HR monitor

transformed biofeedback

provides externally processed information representative of the internal biological process

- EMG and EEG

EMG

representative signal of electrical activity in muscle tissue

EEG

representative signal of electrical activity in brain tissue

intrinsic; extrinsic

EMG biofeedback converts _____ signal to _____ signal

intrinsic

surface electrodes are used to detect _____ activity of muscle tissues which is then converted to extrinsic auditory, visual, or tactile signals to the user

false

T/F: surface electrodes in EMG represent electrical changes in the activity of the muscle and are a DIRECT representation of the ability to generate muscle tension/contraction or muscle strength

narrow

____ placement of electrodes with biofeedback target superficial muscles

wide

______ placement of electrodes with biofeedback targets deeper muscles

issues

_____ with biofeedback

- not possible to isolate one muscle

- surface electrodes represent the changes in electric activity of the muscles NOT the ability to generate muscle tension/contraction

higher gain setting

higher sensitivity of the EMG device

- small changes in electrical activity will produce an EMG signal

- used when patient may have some paresis or only trace muscle contractions (smaller change to produce feedback)

lower gain setting

lower sensitivity of the EMG device

- need greater changes to produce EMG signal

- use when you want the user to have to contract with great effort to produce a stronger contraction before they receive the feedback

shaping

adjusting the gain to control the target process

contraction latency

the time between a command to contract a muscle and the point at which peak amplitude is achieved

return latency

the time it takes for the electrical activity in muscle to return to resting levels following a command to relax

hold capacity

The ability of a muscle to maintain a contraction over time as determined by the stability of measured EMG activity

above threshold

requires a patient to increase the myoelectric activity to produce an EMG signal

- use when muscles are atrophied/weakened

below threshold

requires a patient to decrease the level of myoelectric activity to produce an EMG signal

- use when muscles are tense

neuromuscular facilitation, neuromuscular inhibition, and neuromuscular coordination

what are the 3 physiological effects of biofeedback?

AMI

arthrogenic muscle inhibition

- injury/surgery --> pain and swelling --> inhibition of normal muscle function

- protective mechanism

- leads to atrophy, weakness, and long-term disability

neuromuscular facilitation

reduces AMI effect which increases the muscle's ability to generate force and achieve peak force (MVIC)

- increases motor unit recruitment

- decreases the latency of motor unit recruitment

- increased neural excitability and voluntary activation

neuromuscular inhibition

sometimes muscles are overactive

- used for relaxation, postural training, ther ex to decrease pain/muscle tension/increase ROM/flexibility/function

- used to inhibit the myoelectric activity of a muscle

- decreases muscle tone by reducing activation of motor units

- user attempts to decrease the signal or intensity of the feedback

neuromuscular coordination

used to improve timing and recruitment of muscle activity

- gait

- performance of higher-level functional activities

- athletes, musicians, patients with neurological injuries

- user works with the feedback to try to increase timing and intensity of muscle recruitment for a specific task

indications

____ for EMG biofeedback

- hemiplegia following a stroke

- muscle strengthening

- headache

- pelvic floor disorders

- temporomandibular disorders

- chronic pain conditions

contraindications

_____ for EMG biofeedback

- acute inflammatory conditions

- pregnancy/6 weeks PP

- bladder/vaginal infection

- allergy to metal or electrode material

- over eyes or other sensitive tissues

precautions

____ for EMG biofeedback

- decreased skin sensation

- patients with epilepsy

adverse effects

____ ____ of EMG biofeedback

- dyspnea

- fatigue

- angina or other cardiac related symptoms

- skin irritation from electrodes

- increased pain if used inappropriately

electromagnetic radiation

electric and magnetic fields that vary over time and are oriented perpendicular to each other

natural

____ electromagnetic radiation

- magnetic field of the earth

- UV radiation from the sun

manufactured

_____ electromagnetic radiation

- light bulbs

- electric appliances

- computers

- power lines

lower; deeper

longer wavelength light = ____ frequency = _____ penetration

higher; superficial

shorter wavelength light = ____ frequency = ____ penetration

non-ionizing radiation

cannot break molecular bonds or produce ions

- can be used in therapeutic medical applications

- low frequency

- shortwaves

- microwaves

- IR radiation

- visible light

- UV

ionizing radiation

can break bonds, produce ions, or inhibit cell division

- NOT used clinically, except in small doses for imaging and in large doses to destroy tissue

- X-rays, gamma rays, UV rays

light intensity

power

- rate of energy flow

- measured in W or mW

power density

irradiance

- amount of power per unit area

- measured in mW/cm2

energy density

amount of power per unit area

- measured in J/cm2

fixed

laser and light therapy applicators generally have a ____ power

- may reduce with pulsed output

- lab probes have power output of 500 mW

power (W) x time (s) = energy (J)

what is the energy formula?

dosage

clinicians choose the ____ for light/laser therapy and the time adjusts

high

____ intensity of electromagnetic radiation

- energy output is high

- radiation source is close to the patient

- beam is perpendicular to the surface of the skin

thermal produces superficial heating

what is the clinical effect of infrared radiation?

shortwave/microwave diathermy

heats both superficial and deep tissues

low-average intensity shortwave

nonthermal

- used for pain, edema, and tissue healing

nonthermal, promotes healing, controls pain and inflammation

what is the clinical effect of low-level laser therapy?

light amplification by stimulated emission of radiation

what does LASER stand for?

laser

- monochromatic (made up of light that is only a single wavelength)

- coherent (in phase)

- collimated (directional)

class 1

< 0.5 mW

poses no hazard

class 1M

no hazard

- beam has a large diameter diameter or is divergent

class 2

< 1 mW

- safe for momentary viewing; will provoke a blink reflex

class 3A

< 5 mW

- commonly used for laser pointers

- poses an eye hazard with prolonged exposure

class 3B

< 500 mW

- used for therapy

- can cause permanent eye injury with brief exposure

- direct viewing of beam should be avoided

- viewing of diffuse beam reflected from skin is safe

- can cause minor skin burns with prolonged exposure

class 4

> 500 mW

- surgical and industrial cutting lasers

- can cause permanent eye injury before you can react

- can cause serious skin burns

- can burn clothing

- use with extreme caution

concentrated

LEDs and SLDs do not produce _____ light and are lower power

- do not have the potential to cause damage

lasers

_____ provide high intensity light in one area

LED

light emitting diodes

- not coherent or monochromatic or directional

- low intensity light

- allows light to be delivered to wider area (spreads widely)

SLD

supraluminescent diodes

- almost monochromatic

- not coherent

- spreads less widely than LED

physiological effects

____ ____ of radiation

- can be thermal/nonthermal

- light energy (photons) effect the chromophores in different types of cells

- absorbed light can stimulate chromophores to undergo chemical reactions

- results in cascade of biochemical events which influence the tissue function

effects

physiological ____ of lasers/lights

- promote ATP production

- promote collagen production

- modulate inflammation

- inhibit growth of microorganisms

- promote vasodilation

- alters NCV

mitochondria

where does ATP production occur?

indications

clinical _____ for lasers/lights

- soft tissue and bone healing

- arthritis

- lymphedema

- neurological conditions

- pain management

adverse effects of lasers/lights

- laser irradiation of the eyes

- burns/burning sensation

- mild erythema

- rash

- transient tingling

- increased pain/numbness

laser irradiation of the eyes

what is the primary hazard related to lasers?

goggles

if using a laser ____ are required by both the patient and clinician

increases

UV intensity _____ with

- high power lamp

- lamp placed closer to the treatment surface

- light beam perpendicular to the treatment surface

depth

things that influence the _____ of penetration of UV:

- intensity of UV radiation reaching the skin

- wavelength

- power of radiation source

- size of treatment area

- thickness and pigmentation of the skin

- duration of the treatment

physiological effects of UV

- erythema production

- tanning

- epidermal hyperplasia

- vitamin D synthesis

- bactericidal effects

indications for UV

- psoriasis

- wound healing

adverse effects of UV

- burning

- premature skin aging

- eye damage

- PUVA meds

UV contraindications

- goggles

- skin cancer

- pulmonary TB

- systemic lupus

- cardiac, kidney, liver disease

- fever

UV precautions

- photosensitizing needs

- photosensitivity

- recent x-ray

Suberythemal dose (SED)

A dose of UV that produces no change in skin redness in the 24 hours after exposure.

Minimal Erythemal Dose (MED)

The smallest dose of UV to produce erythema, which appears within 8 hours of exposure and disappears within 24 hours after exposure.

first degree erythema

definite redness within 6 hours, lasts 1-3 days

second degree erythema

intense erythema within 2 hours with edema and peeling

- like a sunburn

third degree erythema

Erythema with severe blistering, peeling, and exudation

0.5-1 MED

what is the typical initial dose of UV?

10-40

you should increase the dose by ____ to ____ percent for subsequent UV treatment

5 minutes

what is the max treatment time for UV?

3-5 x/week (not before previous erythema is resolved)

how often should UV therapy be performed?

50%

what percent of psoriasis plaques are cleared in 15-20 treatments?

60-80 cm

how far away should the UV lamp be for treatment?

4

half the distance (60-80 cm) increases the UV intensity by ____ times

same

you should always use the ____ lamp for UV therapy because the smallest difference in lamps can change skin sensitivity