3. What is Biofeedback ?
๏ถ Procedure by which information about โ Physiological function โ is
fed back to the individual by means of an auditory or visual signal.
๏ถ When presented with this visual or auditory feedback the patient
can attempt to modify the activity.
4. BIOPHYSICAL PRINCIPLES
Biofeedback units operate on one (or more) of four
principles
EMG
Measure electrical activity
Implanted or surface electrodes
Galvanic Skin Response
Measures production of sweat
5. Peripheral Temperature
Measure changes in temperature of the distal
extremities
Increased temp = systemic relaxation
Photoplethysmography
Measures the amount of light reflected by
subcutaneous tissues Ex. Pulse oximeter
6. EMG Biofeedback
๏ฌMeasure electromyographic activity (EMG) indicating
amount of electrical activity during muscle contraction
๏ฌMost common type of biofeedback used in athletic
training and physiotherapy Rehabilitation
7. EMG Biofeedback
โข Nerve fiber conducts an impulse to the neuromuscular junction
where acetylcholine binds to receptor sites on the sarcolemma
inducing a depolarization of the muscle fiber
โข Changes in electrochemical potential difference associated with
depolarization can be detected by an electrode placed in close
proximity
8. s
Measuring Electrical Activity
โข EMG does not measure muscle contraction directly
โข EMG biofeedback unit receives small amounts of
electrical energy generated during muscle
contraction (via the electrodes)
โข Separates or filters electrical energy from other
extraneous electrical activity (non meaningful)on
skin
โข Amplifies the EMG electrical energy and converts it
to some type of information which has meaning to
the patient
- Meter, auditory signal, light display
11. Electrodes
Basic units have one channel composed of three
surface electrodes on a self-adhesive electrode
โActiveโ Electrodes
Detect electrical signal
โReferenceโ Electrode
Filters nonmeaningful information
12. ยฉ 2004
The Process
Identify Signal
Get the eletromyographic signal from the
body
Amplify Signal
Filter out background noise
Similar to a volume control on a radio,
enhance the strength of the signal to
meaningful levels
Rectify Signal
Make all values โpositiveโ
Integrate Signal
Group the data into meaningful
clusters
13.
14. โข The Stabilizer monitors the position of the low back or cervical spine
during muscle testing to determine if the patient is able to selectively
isolate their cervical or lumbopelvic core stabilization muscles.
โข When used during exercise, the Stabilizer provides a patient feedback
as to when they have isolated and are maintaining a contraction of
either the cervical or lumbopelvic core stability muscles.
Pressure Biofeedback
15.
16. Clinical Applications
Muscle re-education
๏ Isometric contractions sustained for 6-10
sec
๏ Tx time = 5-10 min
Relaxation of muscle guarding/Pain control
๏ Concentrate on muscle relaxation
18. Contraindications
โข Any musculoskeletal condition in which a muscle
contraction may exacerbate the condition
โข Unhealed tendon grafts
โข Avulsed tendons
โข Third degree tears of muscle fibers
โข Unstable fracture
โข Injury to joint structure, ligaments, capsule, or
articulating surface