2. MOTOR POINTS

3. OBJECTIVES:
 Motor Point Definition
 Location
 Advantages
 Reactions
 Physiological effects
 Currents
 Electrodes
 Indications
 Contraindications
 Precautions
 Application principles
 Motor points of muscles

4. CLINICALLY; A motor point is a specific skin area
where the targeted muscle is best stimulated
with the smallest amount of current
amplitude and the shortest pulse duration
ANATOMICALLY; This same motor point is
defined as the surface entry point of a bundle
of motor nerve fibers into a fasicle of muscle
fibers

5. LOCATION
 Motor points are frequently at the junction of the
upper and middle one-thirds of the fleshy belly of the
muscles
 Motor points vary from person to person.
 Motor point of deeper muscles are difficult to locate.
 Deeply placed muscles may be stimulated where they
emerge from beneath the more superficial ones

6. WHY TRACING OF MOTOR POINT IS
ESSENTIAL????
• Tracing of a motor point is essential for;
1-Plotting of a SD curve of a muscle
2-Locating the general area for electrode
placement for surged faradic stimulation of
innervated muscles

7. ADVANTAGES OF MOTOR POINT
STIMULATION
• The current intensity required to produce
muscle contraction is minimum, compared to
any other area on the muscle belly, thus
causing mild sensory irritation.

8. ADVANTAGES OF MOTOR POINTS
 Specific muscle performs its own individual action and
that the optimum contraction of each can be obtained.
 It may therefore be selected when training a new
muscle action or when isolation of one muscle is
indicated;
e.g. the vastus medialis may be stimulated to
overcome a quadriceps lag,or abductor hallucis for
muscle weakness.

9. REACTIONS
The application of an electrical stimulus on the skin (motor
points), via an electrode, will cause the following reactions:
Can cause the underlying muscle to contract and will
elicit the greatest muscular contraction.
Can cause pumping action on blood vessels,
improving the venous return, thus inc. in blood flow
to the area.
 Can produce muscle contraction in a partially
denervated muscle.

10. PHYSIOLOGICAL EFFECTS

11. EXCITABILITY OF NERVE CELLS
 When a nerve is
stimulated the stimulus
causes a fall in the
potential difference
across the plasma
membrane which is
termed as ACTION
POTENTIAL
+ + + + + + + ++ +
- - - - - - - - - - - - - - -K+
Na+

12. STAGES OF AP
• RESTING STAGE
• DEPOLARIZATION STAGE
• REPOLALARIZATION STAGE

13. Resting stage
• This is membrane potential of nerve fibers
when they are not transmitting signals
• The RMP in excitable cells as in nerve cells is -
70mV and muscle cells is approximately -
90mV

14. DEPOLARIZATION STAGE
This is the change in the resting membrane
potential from -90mV to 0mV and then to a
positive value 35mV

15. REPOLARIZATION STAGE
• This is a change in the membrane potential
from positive to a negative value 35mV to -
90mV

16. -90-80-70-60-50-40-30-20-100+10+20+30+40mv
Threshold of muscle and nerve
Action potential of nerve
Action potential of muscle

17. CURRENTS USED

18. Most commonly used currents for stimulatory
purposes of nerve and muscles are;
Faradic type of current
Russian current
High Voltage current
TENS (burst mode)

19. FARADIC TYPE CURRENT
 An interrupted direct
currents with a pulse
duration of 0.2 to 1
msec.
 The most comfortable
pulse is 0.1 at 70 Hz

20. RUSSIAN CURRENT
 A 2500 Hz AC
modulated every 10ms
to provide 50 bursts
per sec.

21. HIGH VOLTAGE CURRENT
 A twin-spike
 Waveform:
monophasic pulsed
current
 pulse duration: 5-65s
 Freq: 1-120 pps (low
pps)
 Peak amp: 500 V
(2000-2500 mA)
5-65 µs

22. TENS (burst mode)
 Frequency : 50 to 100 pps
 Phase/pulse duration: 50 to 200
microsecond
 Amplitude : comfortable
/intermittent
 Electrode placement : over motor
points
 Duration of treatment : 15 to 20
minutes
 Indications: acute as well as chronic
pain.

23. Effect of Pulse Frequency on Muscle
Contractions
1 pulse per second
Twitch Contraction
The amount of time
between pulses – the
interpulse interval – is
long enough to allow the
muscle fibers to return to
their original position
20 pulses per second
Summation
The amount of time
between pulses allows
some elongation of the
fibers, but not to their
starting point.
40 pulses per second
Tonic Contraction
The current is flowing so
rapidly that there is not
sufficient time to allow the
fibers to elongate

25. ELECTRODES USED

26. SIZE OF ELECTRODES
 Current density
inversely proportional
to the electrode
contact area

27. METHODS OF ELECTRODE
PLACEMENT
 UNIPOLAR
(Bifurcated)
 BIPOLAR
 QUARDRIPOLAR

28.  Metal electrode
(small lint/sponge pad with a
flat plate-electrode.)
 Carbonised Rubber
Electrode
 Specialised probe

29. Unipolar Motor Point Stimulation
 Electrodes of 2 different sizes
› Active Electrode – placed where the treatment effect
occurs; may be bifurcated
› Dispersive Electrode – completes the circuit; fastened to a
body part @ a distant location (large body mass)
 Site of stimulation: motor point for stronger response
 Smaller sized electrode has higher current density
(stronger effect)
 Little or no stimulation should occur under dispersive
electrode

31. Bipolar Motor Point Stimulation
 Electrodes equal or near-equal size
electrodes
 Both electrodes are located in target treatment
area
 Equal amount of current from each electrode
 Effective for stimulating muscle groups or very
large muscles

33. Quadripolar Motor Point
Stimulation
 Uses 2 sets of electrodes, 2 from each own channel.
 Electrodes from two or more circuits positioned so
that currents geometrically intersect.

35. INDICATIONS
 Muscle strengthening and or muscle exercise
 Treatment of disuse atrophy
 Muscle re-education of movement
 Muscle contraction in partially denervated muscles
 Pumping actions.

36. CONTRAINDICATION
 Cardiac disability
 Demand-type pacemakers
 Pregnancy (over lumbar and abdominal area)
 Menstruation (over lumbar and abdominal area)
 Cancerous lesions (over area)
 Sites of infection (over area)
 Epilepsy
 In the presence of electronic monitoring equipment
 Exposed metal implants

37. PRECAUTIONS
 Sensory loss over treatment site
 Open wounds
 Extreme edema or severe obesity
 Areas of sensitivity
› Carotid sinus
› Esophagus
› Larynx
› Pharynx
› Around the eyes
› Temporal region
› Upper thorax

38. APPLICATION PRINCIPLES
 Conduct general safety checks with respect to the
equipment.
 Check the patient for contraindications
 Explain the treatment fully to the patient
 Collect the necessary equipment
› ES, electrodes, wiring
› Soap & water for cleaning the skin
› Contact gel / sponge, tape / straps

39. Cont………
 Position the patient in the comfortable position
 The skin should be uncovered & examined for any
contraindications to treatment
 Test the equipment as appropriate; demonstrate the
technique to the patient.
 Wash the skin over the region of electrode contact.
Soaking the skin for 3-4 min either in a bath or with a
warm, damp pad may reduce skin resistance.
 Select appropriate treatment parameters.

40. Cont……
 Always turn all intensity dials to zero before
beginning the treatment
 Place the electrodes as appropriate for the
treatment. Increase intensity until desired result is
produced
 Never lift the active electrode from the skin or
replace it without turning the intensity to zero.
 Terminate the treatment; check the skin condition
 Keep a full record of the treatment

42. MOTOR POINTS OF MUSCLES IN
DIFFERENT REGION/PART OF THE
BODY

43. 43

44. 44

45. 45

46. 46

47. 47

48. 48