The role of physical agents in modulating pain.

This article presents a review of the literature on the use of physical agents in modulating pain associated the hand and upper extremity musculoskeletal conditions. The physical agents presented include superficial heating agents, cryotherapy, ultrasound, and transcutaneous electrical nerve stimulation. There has been increased interest in modes of transdermal drug delivery, including iontophoresis, phonophoresis, and the application of transdermal patches. Treatment applications, parameters, and integration strategies are suggested. The purposes of this article are to review which physical agents are used to treat pain or inflammation and to discuss their relevant application to hand therapy practice. Today's health care climate requires therapists to select treatment strategies that are efficient, safe, and clinically effective. Although physical agents are widely used to manage pain in hand therapy, there is little scientific evidence to support their efficacy. Most information regarding the rationale for the use of physical agents in pain management is based on tradition, data extrapolated from basic science research, and uncontrolled randomized clinical trials. This paper discusses the need for additional research to establish clinical efficacy and determine optimal treatment parameters for the physical agents used most often to modulate pain in hand therapy.