Biofeedback does not monitor the strength of the muscle contraction but rather the sonditions associated with the response
Neurological activity
Measures electrial activity of muscle not muscle contraction
No value or the strength
Indications for Biofeedback
Muscle Re-education
Regaining neuromuscular control
Increasing isometric and isotonic strength or a muscle
Relaxtion of muscle spams
Decreasing mucle guarding
Contraindications of Biofeedback
Any musculoskeletal condion in which a musclar contraction might exacerbate that condition
If isometric contraction are contraindicated biofeedback is not used
Electromyographic Biofeedback (EMG)
Measures the electrical activity in skeletal muscle
most typically used of alll the biofeedback modalitied in a clincial setting
Peripheral Temperature
Measures temperature changes in the distal extremities
Increased temperature indicated a relaxed state
Decreased temperature indicates stress, fear or anxiety
Photoplethysmography Biofeedback
Measures the amount of light relected by subcutaneous tissue based on the amount of blood flow
Galvanic Skin Response
Measures the amount of perspiration on the skin by passing a small current through the fingers and or palm
Hoe electrodes work
Teh electrodes meausre the electrial activity wtihin a local area of a muscle (usucally the muscle belly)
the amount of electical activity within the muscle increases as more motor units are recruited into the contraction
these signals are then picked up by the electrodes amplified and converted into visual or auditory signals
Electrode Placement
placed parallel to the dirction of the muscle fibers to encsure that a better sample of muscle activity is monitored while reducing extraceous electrial activity
How the signals are used
High gain: uinti will have a high sensitivty for the muscle activity