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 – 6MWT, 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 analog 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 to 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.