Week 13 EMG, Laser, Diathermy, and Alternative Approaches

Question 1

what is electromyography (EMG)?

Answer 1

the summation of all motor unit action potentials that a sensor can record from the muscle(s) underneath the sensor

Question 2

what does a higher EMG amplitude indicate?

Answer 2

there is more motor unit recruitment or motor units are firing at a higher rate (or both)

Question 3

how does skin impedance and subcutaneous structures affect EMG?

Answer 3

if there is a high impedance the signal will decrease

Question 4

when should you use EMG biofeedback? list some examples.

Answer 4

-to increase muscle activity (motor learning, muscle reeducation, postural training)
-to decrease muscle activity (decrease muscle guarding, relaxation, muscle reeducation)

Question 5

where should the EMG sensor be placed?

Answer 5

the muscle belly

Question 6

what are the two modes of EMG biofeedback?

Answer 6

-above threshold: machine will give auditory/visual feedback when the muscle activity is above the threshold
-below the threshold

Question 7

what are the contraindications of EMG biofeedback?

Answer 7

none

Question 8

what are the precautions of EMG biofeedback?

Answer 8

-open wound
-fragile skin (due to adhesives)
-allergy to adhesive materials or gel
not applicable in patients with sever cognitive impairments due to it requiring cooperation

Question 9

what does laser stand for?

Answer 9

light amplification by stimulated emission of radiation

Question 10

what are the three characteristics of laser that differentiate it from other light sources?

Answer 10

-monochromatic: all photons have a single wavelength and, thus, a single color (or invisible)
-coherent: all photons travel in the same phase and direction
-collimated (parallel): minimal divergence over distance

Question 11

what does wavelength determine in laser?

Answer 11

the depth of penetration

Question 12

what is incident power?

Answer 12

how much of the laser the body will receive

Question 13

what are the two different types of low power laser?

Answer 13

-helium-neon: gaseous; wavelength 400-700nm; visible; lower penetration
-gallium-arsenide: semiconductor; wavelength 600-1200nm; invisible; higher penetration

Question 14

what is the optical window of the skin?

Answer 14

we want the laser to penetrate through the skin and water level to be absorbed by the tissue
600-1200nm

Question 15

how is depth of penetration measured?

Answer 15

the depth at with the 60% of applied energy has been absorbed and 40% is still extending deeper into the tissue

Question 16

what is the optimal wavelength used for effective depth of penetration?

Answer 16

*830nm - infrared 50-60nm

Question 17

what are the effects of laser therapy?

Answer 17

-reduce excitability of nervous tissue
-increased vascularity
-reactivate enzyme
-increase APT release
(all above for pain control)
-stimulate collagen production
-increased RNA and DNA synthesis
-increased lymphatic drainage
-stimulate fibroblastic activity
-increased phagocytosis

Question 18

how is laser classified?

Answer 18

-class I: cd player
-class II: laser pointer/therapeutic
-class IIIA: therapeutic
-class IIIB: therapeutic
-class IV: therapeutic, surgery

Question 19

what are the contraindications/precautions for laser?

Answer 19

-over the eye
-epilepsy
-fever
-near cancerous lesions
-pregnant women (abdominal area)
-active hemorrhage area
-over endocrine glands
-photosensitive

Question 20

what are the indications for laser?

Answer 20

-pain
-inflammation
-wound
-trigger point
-arthritis
-fracture

Question 21

what is diathermy?

Answer 21

high frequency electromagnetic waves penetrate into the body; increases energy of tissues and cells

Question 22

what are the two types of diathermy?

Answer 22

-microwave (300MHz-300GHz): more focal (hot spot) and superficial (skin burn)
-short wave(10-100MHz; FCC assigned 13.56, 40.68, and 27.12MHz): high frequency, short wavelength (11 meter), deeper, continuous or pulsed

Question 23

what is inductive diathermy?

Answer 23

-drum or sleeve
-increase heating of muscle
-less heating of connective tissue

Question 24

what is capacitive diathermy?

Answer 24

-series: treated area between plates; high impedance tissue (fat)
-parallel: both plated over treated area; low impedance tissue (muscle)

Question 25

what are the differences between continuous and pulsed SWD?

Answer 25

-continuous: increased molecular average kinetic energy; thermal heat effect
-pulsed: alteration of cell ion-binding properties, protein synthesis, and ATP production; athermal effect

Question 26

what are the indications for diathermy?

Answer 26

-relief in pain
-relaxation of muscle spasm
-nonacute inflammation
-soft tissue tightness, contractures, and joint stiffness (prior to stretching or ROM)
-to increase blood blow to extremities by heating the low back
-pelvic inflammatory disease
-to promote healing of herpes zoster vesicles

Question 27

what are the contraindications for diatheramy?

Answer 27

-metals on, near, or in the patient
-chest/trunk with pacemaker or ICD
-pregnant or who may be pregnant
-use thermal over acute inflammation
-active bleeding
-eyes or testes
-over cancerous tissues
-hemophilia
-mentally confused or unconscious

Question 28

what are the precautions for diathermy?

Answer 28

-thin soft tissue, bony prominences
-growing epiphyses
-uncooperative patients
-other moist clothes, dressings, or accumulations or persiration
-medical electrical devices
-obese
-over the low back or pelvis in woman who are menstruating

Question 29

what are the indications for hydrotherapy?

Answer 29

-pain
-arthritis
-wounds
-cardiovascular training
-strength/endurance training
-labor

Question 30

what are the contraindications of hydrotherapy?

Answer 30

-impaired sensation
-severe cardiopulmonary disorders
-over bleeding are
-urinary incontinence
-mental disability