Thera

• Electrical Current


  Flow of charged particles (electrons or ion)
• Torpedo fish


  • To alleviate pain
• Animal Electricity

  Effect produced when Galvani produced muscle contraction upon attaching metal to a frog's muscle
• Galvanic Current


  Volta's battery precursor to produce muscle contraction
• Motor points


  Locations on the skin where electrical stimulation most effectively caused specific muscles to contract
• Duchenne


  Discovered motor points
• Faradic Current


  Using moving magnet, Faraday discovered that bidirectional electrical currents could be induced

  
• Law of Excitation


  Intensity and duration of a stimulus = muscle contraction
• Lapicque


  Discovered the Law of Excitation
• Electrical Stimulation today: Clinical applications in rehabilitation


  • Production of muscle contraction
  • Pain control
  • Promotion of tissue healing
• Waveforms


  • Direct Current (DC) aka monophasic
  • Alternating Current (AC) aka biphasic
  • Pulsed Current (PC)

  
• Direct Current (DC)


  Continuous unidirectional flow
• Alternating Current (AC)


  Continuous sinusoidal bidirectional flow

  
• Pulsed Current (PC)


  Interrupted flow, for iontophoresis and for stimulating contractions in denervated muscle
• Interferential Current (IFC)


  Interference of two medium-frequency (1000 to 10,000 Hz) ACs of slightly different frequencies

  
• Premodulated Current


  Alternating current with a medium frequency (1000 to 10,000 Hz), sequentially increasing and decreasing current amplitude

  
• Russian Protocol


  Medium frequency AC, 10 ms long bursts, 50 bursts per second with a 10 ms interburst interval

  
• Monophasic pulsed current


  Current flows in one direction during a pulse

  
• Biphasic pulsed current


  Current flows back and forth during a pulse, may be symmetrical or asymmetrical

  
• Time Dependent Parameters


  • Pulse Duration
  • Phase duration
  • Interpulse interval
  • Amplitude
  • Frequency

  
• On and off time


  On time - time during which a train of pulses occurs, Off time - time between trains of pulses where no current flows
• Ramp up


  Amount of time it takes for the current amplitude to increase from zero during the off time to its maximum amplitude during the on time

  
• Ramp down


  Time it takes for the current amplitude to decrease from its maximum amplitude during the on time to zero during the off time

  
• Effects of Electrical Current


  • Stimulation of Action Potentials
  • Direct Muscle Depolarization
  • Ionic Effects
• Strength Duration Curve


  Amount of electricity required to produce an action potential depends on the type of nerve and can be represented by the nerve's strength-duration curve
• Rheobase


  Minimum current amplitude with very long pulse duration required to produce an action potential

  
• Chronaxie


  Minimum duration it takes to stimulate that tissue at twice rheobase intensity
• Accommodation


  Process by which a nerve gradually becomes less responsive to stimulation
• Innervated muscles


  Contract in response to electrical stimulation when a simulated action potential reaches the muscle via the motor nerve
• Denervated muscles


  Contract when the electrical current directly causes the muscle cells to depolarize, requires pulses of electricity lasting 10 ms or longer
• Contraindications for Electric Current


  • Pacemaker
  • Unstable arrhythmia
  • Over carotid sinus
  • Thrombosis
  • Pregnancy (Lower back and abdomen)
• Precautions for Electrical Current


  • Cardiac disease
  • Impaired mentation and sensation
  • Malignant tumors
  • Skin irritation/open wounds
• Adverse Effects of Electrical Current


  • Burns
  • Skin Inflammation/irritation
  • Painful perception of electric stimulation
• TENS


  Transcutaneous Electrical Nerve Stimulation, for acute and chronic pain
• FES


  Functional Electrical Stimulation, to facilitate muscle and prevent muscle atrophy, heal wounds, temporarily decrease spasticity
• ES


  Electrical Stimulation, for acute and chronic pain, shoulder subluxation, wound healing, lack of muscle contraction
• In FES, the action is performed when there is current, and the patient is instructed to perform the action and lower it gradually
• If the muscle grade is 3, weights can be added in FES
• In ES for neuromuscular conditions like Bell's palsy, the contractions can be counted and documented
• Bell's palsy usually has a 10 minute ES application