Does transcutaneous electrical nerve stimulation (TENS) simultaneously combined with local heat and cold applications enhance pain relief compared with TENS alone in patients with knee osteoarthritis?

[Purpose] The purpose of this study was to investigate whether transcutaneous electrical nerve stimulation simultaneously combined with local heat and cold applications enhances pain relief compared with transcutaneous electrical nerve stimulation alone in patients with knee osteoarthritis. [Subjects and Methods] Fourty-five patients with knee osteoarthritis participated in this study. They were randomly assigned to the following three interventions: transcutaneous electrical nerve stimulation simultaneously combined with local heat using a hot pack; combined with local cold using a cold pack; and transcutaneous electrical nerve stimulation alone. In each intervention, the knee pain level during walking and standing up from a chair, as well as dynamic balance and gait ability were evaluated immediately before and after a single intervention using the visual analogue scale and the timed up & go test, respectively. [Results] A significant improvement in dynamic balance and gait ability was only observed immediately after transcutaneous electrical nerve stimulation simultaneously combined with local heat application, although the degree of pain relief during standing and walking were comparable among the three interventions. [Conclusion] These results suggest that transcutaneous electrical nerve stimulation simultaneously combined with local heat application can immediately improve not only knee pain during standing and walking but also dynamic balance and gait ability in patients with knee osteoarthritis.