Muscle stimulator is device which are used to contract muscles through electric impulse ( i.e electric current ).Muscle stimulator device pass the electric current to the body near to the muscles being stimulated with the help of electrodes that are used to placed in the treated areas .Muscle stimulator device is also called electrical muscle stimulation because the electric current travel from the machine to the electrodes that are attached to treated areas , which in turn electrodes passes the electric current to the tissues . When an electric current travel ( which varies sufficiently in magnitude ) electric signal send from the brain which stimulate the motor nerve in order to produce muscles contraction
BLOCK DIAGRAM OF MUSCLE STIMULATOR
PULSE GENERATOR :- Responsible for producing a low sequence of low amplitude electrical pulses.
WAVEFORM MODULATOR :- It generate a signals that modulate high frequency carrier signal which is produced by pulse generator .
OUTPUT CIRCUIT :- Amplifies low level stimulatory to high level voltage/ current.
POWER SOURCE :- Provide external energy for proper regulation of electrical muscle stimulator machine .
ELECTRODE :- Through which electric current passes on the skin in order to cause muscle contraction.
PLACEMENT OF ELECTRODES
Quadriceps electro stimulation
?To stimulate rectus femoris , proximal electrodes pads are placed 8cms from the insertion to the left and right and distal pad are placed over the quadriceps.
?To stimulate vastus muscles , the electrode should be placed laterally , near to vastus origin whereas distal electrodes are placed laterally over quadriceps
near to vastus insertion.
Biceps brachii electro -stimulation
To stimulate biceps brachii two proximal electrodes is placed near to biceps origin at around armpit height and two distal electrodes over the muscle 5 – 8 cm above the elbow .
Triceps Electro- stimulation
To stimulate triceps brachii muscle, proximal electrodes placed 8 -10 cm from origin with armpit and distal electrodes placed over the triceps muscles.
Trapezius muscle stimulation Two electrodes is placed 5cm below superior region and other two electrodes is placed at the 9th and 10th vertebrae.
Transverse abdominal muscle stimulation
One electrode places below bottom ribs and 2nd electrode placed few cm beneath. Distal electrodes placed parallel to the other pads and above the linea alba.
?Electric current duration used ranges from 0.1 ms to 3 ms. The muscle stimulator device provides durations of 0.01,0.03,0.1,0.3,1,3,10, 30,100 and 300 ms.
? Impulse duration from 0.1 ms to 1 ms known as short duration and it’s is faradic type current . It is used for stimulating normal innervated muscles.
? Impulses with a duration of more than 1ms is known as long duration and it is a galvanic type current . It is used for stimulating denervated muscles .
Note :- Innervated muscles are those muscles when all the nerve fibers supplying the muscles are intact .Denervated muscles these are those when all the nerve fibers supplying the muscles have degenerated
FARADIC TYPE CURRENT
Faradic current is a short duration interrupted direct current .Having a pulse duration of 0.1 to 1 ms and frequency of 50 Hz to 100 Hz.It is used to stimulate innervated muscles
The form of the original faradic current
Faradic type current from a modern electronic stimulator
MODIFIED FARADIC CURRENTS
? Faradic current are surged for treatment purposes in order to prevent fatigue by providing muscles relaxation and produce a near normal tetanic contraction .
? Surging means gradual increase and decrease of the peak intensity
? In order to prevent fatigue of muscles and rapid rise and fall of current surging can be performed.
Various form of faradic type current are :-
The surging pattern
Surged varying in duration
Varying interval between surges
A. B. C.
Saw tooth Triangular Trapezoidal
Surges varying in wave form.
STIMULATION OF MUSCLE GROUP WITH FARADIC TYPE CURRENT
?? QUADRICEPS :- one electrode and pad (17 ×9cm) is placed over the femoral nerve in the femoral triangle which is held in position with the help of sand bag or bandaged and other electrode pad (15×8cm)is placed across motor point and held in position with the help of strap .
? Lumbrical muscles and interossei :- In order to stimulate lumbrical muscles the electrodes are placed transversely across the bottom of the bath , one electrode is placed under the heel and other electrode placed obliquely metatarsal heads
?To stimulate plantar interossei :- one electrode should be place on each side of the foot at the level of metatarsal shafts.
? MUSCLE OF PELVIC FLOOR :- To stimulate muscle of pelvic floor or good contraction of muscles must be obtained with the help of vaginal electrode .
THERAPEUTIC USES OF MUSCLE STIMULATOR
? Increase the range of motion :- the people who suffer a reduced range of motion in their arms , knees , shoulder due to fractures or operations ,the Electrical muscle stimulator used which stimulate the muscles and increased the range of motion.
? Muscle disuse atrophy and muscle reeducation :- No use of muscles for longer period results in muscle atrophy electrical muscle stimulator machine is used which contract muscles and help in strengthen the muscles to prevent disuse atrophy.
? Muscle spasms :- it results when muscles remain contracted which result pain.The electrical muscle stimulatiom machine is used which relaxe the muscles.
? Increase blood circulation :- Electrical muscle stimulator helps in increasing blood circulation which in turn reduced the swelling .
CONTRAINDICATIONS. Do not use on cancerous tissue.
?Do not use on patients with a pacemaker .
?Do not use on pregnant women’s.
?Do not use through carotid sinus area. It may cause increase in blood pressure, reflex vasodilation and slow the heart rate.
?Do not use through broken area or irritated skin.
? Do not use to a patient with undiagnosed pain.
?Do not use over heart or brain.
? Do not use on recent fractures.
? Do not use on patient with impaired sensation.