Surface EMG and Biofeedback Flashcards
Clinical Electromyography
used to evaluate the scope of neuromuscular disease or trauma…as well as assist with establishing anticipated goals and expected outcomes
Types of EMG
nerve conduction velocity
electromyography
Kinesiological Electromyography
used to study muscle activity and establish the role of various muscles in specific activities
How is kinesiological primarily carried out?
Electromyography (primarily surface EMG
sEMG
can also be used as a kinesiological tool to examine muscle function during specific, purposeful tasks or therapeutic regimens
Biofeedback:
describe the use of instrumentation to make covert physiological processes more apparent to the patient.
Motor unit:
LMN and all muscle fibers it connects to
MUAP
motor unit AP
the electrical activity that comes with the depolarization of a single motor unit
CMUAP:
Combined Motor unit AP: the net (sum) of all depolarization (electrical activity) that comes when a patient voluntarily contracts a muscle to move
3 phases to any instrumentation that is used to sense and record any electrical activity of muscle:
Input phase
Processing phase
Display (feedback phase)
Best and most widely used electrodes?
silver-silver chloride
Kinds of electrodes:
reusable/permanent
single use/disposable
Permanent:
do not need gel: placed on clean skin and taped on
Single use
pre-gelled, self-adhesive
Recording electrodes:
2/3 electrodes are recording “active: ones that sense electrical activity
Isolation ground/reference
make sure that 2 active electrodes are picking up activity from patient
Why do we use 2 active electrodes?
The machine compared the polarity of 2 electrodes.
Location of active electrodes?
generally placed at the midpoint of the muscle being recorded in line with the muscle fibers
Electrode location placement consideration:
Place electrodes “in position of movement (squat)
Consider how skin may “shift” over the underlying muscle during movement
What does spacing effect?
how much of muscle you sample electricity from
Volume Conduction
salt water conducts electricity through its volume to surface of the skin
Cross talk
if electrodes placed far apart; salt water can conduct electricity from other muscle groups and the electrodes can pick it up
Artifact:
An “excess” or “erroneous” signal that is detected and displayed but does not come from the electrical activity of motor neurons or muscle tissue
Movement artifact:
cables of machine do not move too much: can cause electrical display to shift
physical movement, not electrical activity
