Abstract
Objective
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.
Design
Randomised, controlled trial.
Setting
University laboratory.
Participants
One hundred and twelve healthy women.
Interventions
Volunteers were allocated at random to seven groups (n = 16): (1) control, (2) placebo TENS, (3) conventional TENS, (4) burst TENS, (5) cryotherapy, (6) cryotherapy in combination with burst TENS, and (7) cryotherapy in combination with conventional TENS. Pain threshold and tolerance were measured by applying a pressure algometer at the lateral epicondyle of the humerus, before and after each intervention.
Main outcome measures
The primary outcome measure was pressure pain threshold.
Results
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).
Conclusion
These results support the use of cryotherapy in combination with burst TENS to reduce induced pain, and suggest a potentiating effect when these techniques are combined. No such association was found between cryotherapy and conventional TENS.
Citation
Effect of burst TENS and conventional TENS combined with cryotherapy on pressure pain threshold: randomised, controlled, clinical trial.