A comparison of true and premodulated interferential currents.
OBJECTIVE
To compare true and premodulated interferential currents (IFCs) in terms of sensory, motor, and pain thresholds; maximum electrically induced torque (MEIT); and comfort.


METHODS
Repeated-measures design.


METHODS
Laboratory setting.


METHODS
University student and staff volunteers.


METHODS
Participants were exposed to 4 different conditions, chosen to evaluate 2 fundamental differences between true and premodulated IFCs. The conditions were different combinations of (1) premodulated or constant-amplitude currents applied at the skin and (2) crossed or parallel current paths.


METHODS
Sensory, motor, and pain thresholds; MEIT; and subjective reports of relative discomfort were recorded for each of the 4 conditions. Motor to sensory threshold ratios were subsequently calculated to assess depth efficiency of stimulation.


RESULTS
The major findings were that crossed currents (true IFC) had no advantage over parallel currents (premodulated IFC) in terms of motor to sensory threshold ratio, MEIT, or comfort, and that premodulated currents produced higher torque values and less discomfort than constant-amplitude currents (true IFC). These results contradict the claimed superiority of true IFC.


CONCLUSIONS
The findings indicate that premodulated IFC, delivered via 2 large electrodes, may be clinically more effective than the traditional true IFC arrangement in terms of depth efficiency, torque production, and patient comfort.
Ozcan
John
J
School of Physiotherapy, La Trobe University, Victoria, Australia.
Ward
Alex R
AR
Robertson
Valma J
VJ
D000328:Adult; D000344:Afferent Pathways / Q000502:physiology*; D004525:Efferent Pathways / Q000502:physiology*; D004566:Electrodes; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009046:Motor Neurons / Q000502:physiology*; D009119:Muscle Contraction / Q000502:physiology; D017288:Pain Threshold / Q000502:physiology*; D012016:Reference Values; D004561:Transcutaneous Electric Nerve Stimulation / Q000379:methods*