Association Between Racket Stiffness and Lateral Epicondylalgia in Tennis Players: A Multicenter Observational Study
Background. Lateral epicondylalgia is common in tennis and is associated with pain and functional limitation. Although racket stiffness has been experimentally linked to vibration transmission, its clinical association with this condition in tennis players remains insufficiently studied. Objective. To evaluate the association between racket stiffness and the presence of lateral epicondylalgia in adult tennis players, and to examine the potential effect modification by sex and competitive level on this association. Methods. An analytical observational study with a cross-sectional design will be conducted. A total of 200 athletes will be recruited. The primary outcome will be the presence of lateral epicondylalgia within the previous 12 months. Functional severity will be assessed using the Patient-Rated Tennis Elbow Evaluation Questionnaire. The main independent variable will be racket stiffness (RA/stiffness). Secondary variables will include string age, use of a vibration dampener, and exposure related to playing load and technique. Potential confounders will include sex, competitive level, age, anthropometric characteristics, smoking status, prior history of elbow pain, occupational ergonomics involving repetitive gripping (ISO 11228-3 criteria), sleep quality (Pittsburgh Sleep Quality Index), and racket characteristics. The prevalence of lateral epicondylalgia will be estimated, and multivariable logistic regression models will be used to assess the association between racket stiffness and lateral epicondylalgia, including interaction terms to evaluate effect modification by sex and competitive level. Expected results. To determine the prevalence of lateral epicondylalgia in adult tennis players and to identify the association between racket stiffness and the presence of this condition, as well as the potential modifying effects of sex and competitive level.
• Tennis players aged 16 years or older.
• Regular tennis practice over the previous 12 months, defined as at least one weekly training or competition session.
• Habitual use of an adult tennis racket weighing more than 280 grams for training and competition for a minimum period of three months prior to data collection.
• Provision of written informed consent. Players with a history of elbow pain related to tennis practice will be eligible for inclusion and this information will be recorded as an independent clinical variable.