Use of transcutaneous electrical nerve stimulation along with functional tasks for immediate pain relief in individuals with knee osteoarthritis.

Background: Knee pain is the major complaint in individuals with knee osteoarthritis (OA), and the effects of transcutaneous electrical nerve stimulation (TENS) on knee pain are controversial. The present study applied TENS along with functional tests to investigate its effect on pain level in individuals with mild-to-moderate knee OA.

Methods: Twenty volunteers with knee OA classification of graded 2-3 performed four functional tests (stair climb test [SCT], timed up and go test [TUG], 6-minute walk test [6-MWT], knee extensor strength test [KES], and 2-step test from the locomotive syndrome risk test [LSR_2ST]) while wearing either an active or inactive TENS. Knee pain level before and after each test was self-accessed by the Visual Analogue Scale (VAS). The effect of TENS (active vs. inactive) on pain level was submitted to statistical analyses.

Results: Knee pain during SCT, TUG, and LSR_2ST tests was significantly lower when subjects used the active TENS, compared with using the inactive unit. The effect of the active TENS on pain level was also more significant in subjects with no anxiety or depression.

Conclusions: The results provided evidence of immediate pain relief in individuals with mild-to-moderate knee OA when TENS is applied along with functional activities, that usually induced pain in people with knee OA.

Significance: The use of transcutaneous electrical nerve stimulation (TENS) in pain management is still unclear. In this study, the analgesic effects of TENS in people with knee osteoarthritis (OA) were found effective when applied along with functional activities. Therefore, study findings provided clinical evidence for the use of TENS during functional activities as a conservative approach to reduce knee OA pain.