There is some potential risk from doing stretches, exercises and typical physical therapy modalities, but they are rare.
Current research shows exercises and stretches are more effective than rest alone; treatments like ultrasound do not have a great deal of research evidence but may be worth a try. Specific modalities and procedures such as low-level laser therapy and extracorporeal shock wave treatment are considered separately. Most guidelines support physical therapy especially in the acute phase to assist patients in reducing pain, learning stretches and prevention strategies. Many chiropractors and physicians can provide these approaches as well.
Coombes BK, Bisset L, Brooks P, Khan A, Vicenzino B. Effect of corticosteroid injection, physiotherapy, or both on clinical outcomes in patients with unilateral lateral epicondylalgia: a randomized controlled trial. JAMA. 2013 Feb 6;309(5):461-9. doi: 10.1001/jama.2013.129.
Overall there are many different therapeutic approaches to LET and no high-quality evidence definitively supports one approach over others.
Once taught you can do the stretches and exercises on your own. Most physical therapy treatments need to be done by professionals.
Professional instruction in exercises and therapy runs between $20 and $60 per session, with therapies priced about the same. Typically providers will treat 2-3 times per week for several weeks depending on response. If no improvement is noted after 6-12 visits a different treatment approach should be tried. Insurance may cover most of these costs.
USEFULNESS (overall rating): 4/5
How well LET responds to many treatments, including physical therapy treatments, depends on how chronic the condition is and the extent of the damage. Unsurprisingly, studies show that treatment is more effective earlier in the condition, rather than later. Stretching and certain exercises have been shown to be helpful, and therapy is shown to be more effective than rest alone. Some physical therapy modalities, however, such as electrical muscle stimulation, have almost no support in the scientific literature, and other commonly used treatments such as therapeutic ultrasound, have been shown to help in some studies, and not in others. In general, stretches and exercise should be part of every LET treatment program, while other approaches like ultrasound can be tried but should show benefit within a few treatments or they should be abandoned.