title: The effects of transcutaneous electrical nerve stimulation on tissue repair: A literature review.
abstract: BACKGROUND
  Transcutaneous electrical nerve stimulation (TENS) consists of a generic application of low-frequency, pulsed electrical currents transmitted by electrodes through the skin surface. It is a therapeutic modality that is nonpharmacological, noninvasive, inexpensive, easy to use and widely applied in clinical practice.
  
  
  OBJECTIVE
  To narratively review the scientific evidence of the effects of TENS on tissue repair with respect to wound healing, skin flap viability and tendinous repair.
  
  
  METHODS
  The study was conducted using the MEDLINE, Lilacs and Scielo databases, without limit to the period of publication, and was completed in November 2011. Inclusion criteria were randomized or nonrandomized, controlled or noncontrolled clinical trials, and experimental trials involving rats subjected to TENS for tissue repair.
  
  
  RESULTS
  Thirty articles on tissue repair were found and, among these, 14 reported on wound healing, 14 reported on skin flaps and two analyzed tedinous repair.
  
  
  CONCLUSIONS
  It was suggested that TENS stimulates skin wound healing and tendon repair, as well as the viability of random skin flaps. Such effects may be due to the release of substance P and calcitonin gene-related peptide, which would increase blood flow and, consequently, hasten the events leading to tissue repair.
  
  
  CONCLUSIONS
  Based on the scientific evidence regarding the effects of TENS on tissue repair, the findings of the present literature review were inconclusive because data from the randomized controlled clinical trials were insufficient to confirm such effects.
authors.affiliation: Physical Therapy Department, São Paulo City University, São Paulo, Brazil.
authors.forename: Aline Fernanda Perez
authors.initials: AF
authors.lastname: Machado
authors.forename: Eduardo Ferreira
authors.initials: EF
authors.lastname: Santana
authors.forename: Pascale Mutti
authors.initials: PM
authors.lastname: Tacani
authors.forename: Richard Eloin
authors.initials: RE
authors.lastname: Liebano
keywords: Achilles tendon; Literature review; Physical therapy modalities; Skin flaps; Transcutaneous electric nerve stimulation; Wound healing