Figure 13.

(a) Pattern (mode) of pulse delivery of TENS: * We were able to infer that a continuous pattern of pulse delivery was used to deliver high frequency currents in instances where the pattern of pulse delivery was not clearly stated in the study report. ** We were able to infer that a low frequency bursts (trains) of high frequency pulses were used in instances where the pattern of pulse delivery was not clearly stated in the study report; (b) frequency of pulse delivery of TENS: * Including instances where modulated or alterating pulse frequencies were used or frequencies were prn.