Electical Agents

Question 1

Types of current used for each electrical stimulating agent

Answer 1

Interferential therapy= amplitude modulated alternating current

Transcutaneous electrical nerve stimulation (TENS)= asymmetric biphasic pulsed current

Neuromuscular electrical stimulation=. Biphasic pulsed current

Question 2

What is a beat frequency

Answer 2

Difference between alternating current A and B
Applied at constant rate thus the nerve tissue accommodates to the current

Stimulate NS and promote physiological effect

Question 3

What is frequency sweep

Answer 3

To prevent accommodation the beat frequency can be changed gradually throughout using frequency sweep

Question 4

Physiological effects of interferential therapy : analgesic mechanism

Answer 4

Inhibition of c-fibres
Pain gait theory (100 Hz)
Descending pain modulation pathways = endogenous opioid release (low intensity)
Placebo mechanism

Question 5

Physiological effect of interferential therapy : circulatory mechanism

Answer 5

Stimulate. Peripheral nerve @ dorsal root of spinal column = vasodilation
Stimulates = musculoskeletal pump
Inhibit sympathetic nervous syst act

Question 6

Therapeutic benefits of interferential therapy

Answer 6

Pain reduction
Muscle stimulation
Reduce local oedema

Question 7

Pre cautions with interferential therapy

Answer 7

Discontinue if synptoms get worse
Test machine
Consultation if pt has epilepsy
Avoid direct contact with skin sensation is compromised

Question 8

Contra-indications of interferential therapy

Answer 8

Uncooperative pt
Pt with cardiac pacemaker (avid direct application over ant chest wall)
Over uterus in pregnancy (avoid muscle stimulation)
Suspected malignancy
Over carotid sinus

Question 9

Different types of electrodes and how applied

Answer 9

Plate electrodes= using wet sponge

Suction electrodes =

Question 10

3 methods of application for electrode positioning

Answer 10

1) static interference
When using 4 pole = area of interference will be produced at 45 degrees to perpendicular-lines between electrodes
Zone of interference = consistent

2) dynamic interference:
4 pole application= zone of interference can shift + changes in current intensity
Treatment of large generalised areas

3)Bipolar interference:
2 pole = treatment zone between electrode plates
Superficial and localised complaints

Question 11

What is TENS

Answer 11

Introduces electrical current into system and thus depolarises sensory nerves = formation of action potential and physiological changes

Question 12

Hoe does TENS achieve pain relieving effect through various mechanisms

Answer 12

Pain gate activation
Descending pain inhibition= release endogenous opioid
Placebo machanism

Question 13

Name the first TENS treatment protocol

Answer 13

High TENS (90-130 Hz)
Pulse duration: 200 us
Treatment: 30 min
Carry over effect = short

Question 14

Name 2nd TENS treatment protocol

Answer 14

Low TENS: 2-5 Hz
Higher intensity
Pulse width: 200-250 us
Treatment: 30 min 
Takes longer to feel effect BUT
Carry over effect= several-hours

Question 15

Name 3rd TENS treatment protocol

Answer 15

Brief intense TENS (80-130 Hz)
High frequency 
High pulse duration 
High current delivery
15-30 min