Effects of TENS with home exercise improve pain and muscle strength in older adults with pre-radiographic to mild knee osteoarthritis

To date, no large-scale studies have been conducted on pre-radiographic to mild cases of knee osteoarthritis. Therefore, this randomized, double-masked, sham-controlled trial investigated the effects of transcutaneous electrical nerve stimulation (TENS) combined with home exercise in older individuals with pre-radiographic to mild knee osteoarthritis (Kellgren-Lawrence grade ≤ 2). A total of 126 participants experiencing knee pain were randomly assigned to the TENS (n = 64) or sham TENS group (n = 62), both combined with home exercise. The main outcome was knee pain during activity, measured via a visual analog scale (VAS). Both groups showed significantly decreased VAS scores during activity, with greater reductions in the TENS group than in the sham TENS group. Compared with the sham TENS group, the TENS group also showed significantly increased knee extensor strength in the painful knee, with no changes in the non-painful knee. No significant changes were observed in gait ability, physical activities, activities of daily living, and mental health between the groups. In conclusion, TENS combined with home exercise can reduce knee pain and increase knee extensor strength in older individuals with pre-radiographic to mild knee osteoarthritis.