Biofeedback

Question 1

What is biofeedback?

Answer 1

• Using information from the body to help control functions.
• using information about muscle contraction to modify muscle activity

Biofeedback can involve various sensory inputs to modify motor control.

Question 2

What does EMG biofeedback involve?

Answer 2

Using information about muscle contractions to modify (increase or decrease) muscle activity.

EMG stands for electromyography.

Question 3

What are the requirements for EMG biofeedback?

Answer 3

• Active participation of the patient
• Sensor electrodes to sense electrical activity
• No electricity is administered to the patient
• patient needs to be able to use the biofeedback information

Question 4

List the uses of EMG biofeedback.

Answer 4

• Improve motor control
• Relax an overactive muscle
• Increase activity in a weak or underactive muscle
• Can be used even if electrical stimulation is contraindicated.

Question 5

What are the principles of EMG biofeedback?

Answer 5

• Uses visual or auditory feedback to modify muscle activity
• Electrodes detect muscle activity
• Sensitivity of recording device can usually be modified

Question 6

What types of electrodes are used in EMG biofeedback?

Answer 6

• Standard
• Button

Electrode type varies with the unit.

Question 7

How does electrode size affect EMG biofeedback?

Answer 7

Larger electrodes detect more muscle fibers.

Increased distance between electrodes allows detection from a larger muscle volume.

Question 8

What is the unit of measurement for electrical activity in EMG biofeedback?

Answer 8

Measured in microvolts (µV).

Question 9

What does the gain setting in EMG biofeedback indicate?

Answer 9

• The sensitivity of the device to detect muscle contractions.
• A lower gain means increased sensitivity.

• 1uV = unit can detect very small muscle contractions (needed when volitional activity is low)
• 1000 uV means more muscle activity needed for the machine to detect a contraction (used when volitional activity is high)

Question 10

What does a gain setting of 1 µV mean?

Answer 10

The unit can detect very small muscle contractions.

Question 11

What does a gain setting of 1000 µV mean?

Answer 11

More muscle activity is needed for the machine to detect contraction.

Question 12

What is the EMG biofeedback threshold?

Answer 12

• The level of muscle activity the patient is able to reach.
• can use threshold to uptrain or downtrain muscle

Question 13

How can the EMG biofeedback threshold be used in therapy?

Answer 13

• Uptrain muscle activity
• Downtrain muscle activity

Question 14

What is uptraining in EMG biofeedback?

Answer 14

• Working to have the patient exceed the threshold for muscle activity.
• visual/auditory signal when patient contracts muscle above threshold
• used when muscle in underactive/weak

Question 15

What is downtraining in EMG biofeedback?

Answer 15

• Working to inhibit muscle activity to decrease contraction levels.
• if a muscle is overactive
• can have visual or auditory signals

Question 16

What is an example of initial settings for a patient post-surgery in EMG biofeedback?

Decreased muscle contraction

Answer 16

• Set gain low for high sensitivity to detect small muscle contractions.
• electrodes can be wide to detect any part of muscle contracting
• as patient progresses increase gain (which means greater muscle contraction will be needed for machine to register activity)
• electrod placement can be more narrow as they progress

Question 17

What are other examples of biofeedback?

Answer 17

• Pressure biofeedback
• Wii / Wii balance board / Dance Dance Revolution / Video games
• Mirrors / mirror therapy
• Photos for posture
• Video movement analysis / electronic walkways