Effect of burst TENS and conventional TENS combined with cryotherapy on pressure pain threshold

The objective of present study was to assess the immediate effect of conventional and burst transcutaneous electrical nerve stimulation (TENS) in combination with cryotherapy on pain threshold and tolerance in healthy individuals. Volunteers were placed at random into seven groups (n=16): control, placebo TENS, conventional TENS, burst TENS, cryotherapy, cryotherapy in combination with burst TENS, and cryotherapy combined with conventional TENS. Pain threshold and tolerance were measured by the application of a pressure algometer at the lateral epicondyle of the humerus, before and after each intervention. A significant increase in pain threshold and tolerance at the 5% level of significance was recorded as follows: burst TENS {pain threshold: mean difference 1.3 [95% confidence interval (CI) 1.4 to 1.2]; pain tolerance: mean difference 3.8 (95% CI 3.9 to 3.7)}, cryotherapy [pain threshold: mean difference 1.3 (95% CI 1.4 to 1.2); pain tolerance: mean difference 1.9 (95% CI 1.8 to 2.0)] and cryotherapy in combination with burst TENS [pain threshold: mean difference 2.6 (95% CI 2.4 to 2.8); pain tolerance: mean difference 4.9 (95% CI 5.0 to 4.8)]. Cryotherapy in combination with burst TENS provided greater analgesia compared with the other groups (P<0.001).

These results support the use of cryotherapy in combination with burst TENS to decrease induced pain, and are suggestive of a potentiating effect when these techniques are combined. No such association was between cryotherapy and conventional TENS.