Background Deep transverse friction massage, one of several physical therapy interventions suggested for the management of tendinitis pain, was first demonstrated in the 1930s by Dr James Cyriax, a renowned orthopedic surgeon in England. Its goal is to prevent abnormal fibrous adhesions and abnormal scarring. This is an update of a Cochrane review first published in 2001.Objectives To assess the benefits and harms of deep transverse friction massage for treating lateral elbow or lateral knee tendinitis.Search methods We searched the following electronic databases: the specialized central registry of the Cochrane Field of Physical and Related Therapies,the Cochrane Central Register of Controlled Trials (CENTRAL),MEDLINE, EMBASE, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), Clinicaltrials.gov, and the Physiotherapy Evidence Database (PEDro), up until July 2014. The reference lists of these trials were consulted for additional studies.Selection criteria All randomized controlled trials (RCTs) and controlled clinical trials (CCTs) comparing deep transverse friction massage with control or other active interventions for study participants with two eligible types of tendinitis (ie, extensor carpi radialis tendinitis (lateral elbow tendinitis, tennis elbow or lateral epicondylitis or lateralis epicondylitis humeri) and iliotibial band friction syndrome (lateral knee tendinitis)) were selected. Only studies published in English and French languages were included.Data collection and analysis Two review authors independently assessed the studies on the basis of inclusion and exclusion criteria. Results of individual trials were extracted from the included study using extraction forms prepared by two independent review authors before the review was begun.Data were cross-checked by a third review author. Risk of bias of the included studies was assessed using the "Risk of bias"tool of The Cochrane Collaboration. A pooled analysis was performed using mean difference (MD) for continuous outcomes and risk ratio (RR)for dichotomous outcomes with 95% confidence intervals (CIs).Main results Two RCTs (no new additional studies in this update) with 57 participants met the inclusion criteria. These studies demonstrated high risk of performance and detection bias, and the risk of selection, attrition, and reporting bias was unclear.The first study included 40 participants with lateral elbow tendinitis and compared (1) deep transverse friction massage combined with therapeutic ultrasound and placebo ointment (n = 11) versus therapeutic ultrasound and placebo ointment only (n = 9) and (2)deep transverse friction massage combined with phonophoresis (n = 10) versus phonophoresis only (n = 10). No statistically significant differences were reported within five weeks for mean change in pain on a 0 to 100 visual analog scale (VAS) (MD -6.60, 95%CI -28.60 to 15.40; 7% absolute improvement), grip strength measured in kilograms of force (MD 0.10, 95% CI -0.16 to 0.36) and function ona 0 to 100 VAS (MD -1.80, 95% CI -0.18.64 to 15.04; 2% improvement), pain-free function index measured as the number of painfree items (MD 1.10, 95% CI -1.00 to 3.20) and functional status (RR 3.3, 95% CI 0.4 to 24.3) for deep transverse friction massage,and therapeutic ultrasound and placebo ointment compared with therapeutic ultrasound and placebo ointment only. Likewise for deep transverse friction massage and phonophoresis compared with phonophoresis alone, no statistically significant differences were found for pain (MD -1.2, 95% CI -20.24 to 17.84; 1% improvement), grip strength (MD -0.20, 95% CI -0.46 to 0.06) and function (MD3.70, 95% CI -14.13 to 21.53; 4% improvement). In addition, the GRADE (Grades of Recommendation, Assessment, Development and Evaluation) approach was used to evaluate the quality of evidence for the pain outcome, which received a score of "very low".Pain relief of 30% or greater, quality of life, patient global assessment, adverse events, and withdrawals due to adverse events were not assessed or reported.The second study included 17 participants with iliotibial band friction syndrome (knee tendinitis) and compared deep transverse friction massage with physical therapy intervention versus physical therapy intervention alone, at two weeks. Deep transverse friction massage with physical therapy intervention showed no statistically significant differences in the three measures of pain relief on a 0 to 10 VAS when compared with physical therapy alone: daily pain (MD -0.40, 95% CI -0.80 to -0.00; absolute improvement 4%), pain while running (scale from 0 to 150) (MD -3.00, 95% CI -11.08 to 5.08), and percentage of maximum pain while running (MD -0.10, 95% CI -3.97 to 3.77). For the pain outcome, absolute improvement showed a 4% reduction in pain. However, the quality of the body of evidence received a grade of "very low."Pain relief of 30% or greater, function, quality of life, patient global assessment of success, adverse events, and withdrawals due to adverse events were not assessed or reported.Authors' conclusions We do not have sufficient evidence to determine the effects of deep transverse friction on pain, improvement in grip strength, and functional status for patients with lateral elbow tendinitis or knee tendinitis, as no evidence of clinically important benefits was found.The confidence intervals of the estimate of effects overlapped the null value for deep transverse friction massage in combination with physical therapy compared with physical therapy alone in the treatment of lateral elbow tendinitis and knee tendinitis. These conclusions are limited by the small sample size of the included randomized controlled trials. Future trials, utilizing specific methods and adequate sample sizes, are needed before conclusions can be drawn regarding the specific effects of deep transverse friction massage on lateral elbow tendinitis.