Additional Study Information: This study will assess the effects of strain counterstain, a gentle osteopathic manipulative technique, on tennis elbow (lateral epicondylitis). Participants will be asked to come to CUMC campus for 4 visits. At each visit, participants will complete a questionnaire and undergo a physical assessment of their upper extremity strength and range of motion. All participants will receive treatment for tennis elbow with half of the participants receiving additional strain counterstain therapy.