ES: Medium Frequency

Question 1

ES: Medium Frequency Currents - Concept

Answer 1

• Frequencies of 2000-5000 pps are modulated to produce physiologically applied frequencies.
• An increase in frequency decreases skin resistance to the current.
• This concept is utilized in Russian and interferential current.
• Low frequency: 1-1000 pps
• Medium frequency: 1000-10,000 pps
• High frequency: >10,000 pps

Question 2

ES: Medium Frequency Currents - Russian Currents

Answer 2

• “Medium frequency, burst modulated current”
• Time-modulated 2,500 Hz sine wave is interrrupted for 10 ms at 10ms intervals producing 50, 10 ms bursts per second.
• Biphasic sinusoidal Continuous pulsitile with burst modulation
  
  • Amplitude: Tetanic contraction
  • Pulse rate: 50-70 pps
  • Pulse duration: 150-200 microsec
  • Ramp: 1-5 sec based on pt tolerance
  • Duty cycle:
    
    • 1:5 For isometric exercise, slow isokinetic exercise (5-10 deg/sec)
    • short arc movement when ROM is restricted

Question 3

ES: Medium Frequency Currents - Russian Currents - muscle spasm protocol

Answer 3

• Muscle fatigue using continuous isometric contraction for several minutes to tolerance
• If muscle pumping is goa; duty cycle is 1:1
• If ROM is goal duty cycle is 2:5

Question 4

ES: Medium Frequency Currents - Interferential Current (IFC)

Answer 4

• Crossing of two sinusoidal waves with similar amplitudes, different frequencies
• Generates amplitude modulated beat Beat frequency is the net difference between the two
• Produces a clover-like pattern as stimulating effect is at a 45 deg angle to the flow of current in the two circuits
• Constant: Both carrier frequencies are fixed, static interferential fields
• Sweep (variable): One fixed, the other variable. Interferential fields rotate 45 deg - purportedly provides greater area of stimulation than static.
• Full field scanning - Produces similar effect as sweep by bursting the current over the two circuits
• When applying IFC to a small area (2 electrodes) the interference occurs in the ES unit and is delivered as a premodulated current through one circuit

Question 5

ES: Medium Frequency Currents - Interferential Current (IFC) - indications

Answer 5

Pain relief Muscle strengthening /ROM

Question 6

ES: Medium Frequency Currents - Interferential Current (IFC) - parameters

Answer 6

• Sinusoidal waveform Continuous (pain), interrupted (muscle exercise)
• Pain protocol is similar to high or low rate TENS
• Muscle strengthening is similar to low/medium frequency elec stim
• Carrier frequency = 4000 Hz
• Bipolar: Premodulated IFC, active and dispersive electrodes placed over or around small area
• Quadripolar: 2sets of electrodes placed diagonally to one another over large area.
• Treatment parameters
  
  • Pain protocol = similar to high or low rate TENS
  • Ms Strength protocol = low or med frequency ES