Association Between Racket Stiffness and Lateral Epicondylalgia in Tennis Players

N/ANot Yet RecruitingNCT07406802

University of Oviedo200 enrolled

Overview

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.

Study Type

OBSERVATIONAL

Enrollment

200

Conditions

Tennis Elbow

Interventions

Eligibility

Sex: ALLMin age: 16 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * 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. Exclusion Criteria: * Players with a history of upper-limb surgery within the previous year. * Athletes with a prior medical diagnosis of neurological or rheumatological disease that could affect the upper limb. * Athletes who sustained an acute traumatic injury to the shoulder, elbow, or wrist within the six months preceding the study. * Participants who fail to complete the study questionnaires correctly.

Outcomes

Primary Outcomes

Measurement of Clinical of lateral epicondylalgia within the previous 12 months.

Lateral epicondylalgia will be assessed using the Patient-Rated Tennis Elbow Evaluation (PRTEE) Questionnaire. This instrument evaluates pain and functional disability in individuals with lateral epicondylalgia. The questionnaire consists of 15 items. The total PRTEE score is transformed to a 0-100 scale, where 0 indicates no pain or disability and 100 represents the worst possible pain and functional impairment.

Time frame: Screening visit

Secondary Outcomes

Measurement of racket stiffness.

Racket stiffness will be assessed using the measured stiffness value (RA) or stiffness index. As not all racket models report this parameter, when participants are unaware of the RA value, it will be determined based on the exact brand, model, and year of manufacture, and subsequently obtained from manufacturer catalogs or technical reference tables. The unit of measurement will be the RA rating (Racquet Analysis rating), also referred to as the stiffness index.

Time frame: Screening visit

Measurement of string age.

String age will be measured as the number of months since the last restringing. This variable will be used as a mechanical proxy for string condition, as commonly applied in biomechanical studies and technical-sport performance recommendations.

Time frame: Screening visit

Measurement of vibration dampener use

Vibration dampener use will be recorded as a dichotomous variable (yes/no). When applicable, the specific dampener model will be documented. This variable is a recognized modifier of the vibratory spectrum, as described in experimental studies.

Time frame: Screening visit

Measurement of load exposure and playing technique

In this variable, data will be collected on the number of weekly training hours (measured in hours/week).

Time frame: Screening visit