This randomised, controlled, double-blind experimental study is designed to evaluate the efficacy of a standardised manual physiotherapy protocol for treating lateral epicondylalgia of the humerus, commonly known as 'tennis elbow'. The study will compare the results for patients receiving active treatment with those for a control group who will follow a watchful waiting approach. Secondary objectives include analysing the relationship between pain, grip strength and joint mobility in the elbow and cervical spine. A sample of healthy subjects will also be included to establish baseline data and measure the effects of the protocol in an asymptomatic population.