This study will investigate the reproducibility of a clinical diagnostic classification system for groin pain between two different examiners.

Groin pain is prevalent in field and court sport athletes. It is particularly prevalent in soccer, Gaelic football and rugby union. The wide variety of possible injuries in numerous anatomical structures and high prevalence of "abnormal imaging findings" in asymptomatic athletes contribute to the complexity. Heterogeneous taxonomy of groin injuries in athletes adds further to the confusion. Clinical practice is challenging with clinicians using differing groin pain terminology, where even the same term can have multiple interpretations. A recent systematic review on the treatment of groin pain in athletes included 72 studies, in which 33 different diagnostic terms were used. The "Doha agreement meeting on terminology and definitions in groin pain in athletes" was convened to attempt to resolve this problem. The Doha agreement meeting on terminology and definitions in groin pain in athletes reached a consensus on a clinically based taxonomy using three major categories. These definitions and terminology are based on history and physical examination to categorize athletes, making it simple and suitable for both clinical practice and research.

The purpose of this study is therefore to investigate the inter-examiner reliability of the "Doha agreement meeting on terminology and definitions in groin pain in athletes." The study will be performed at a Sports Medicine Hospital in Qatar.

Prior to the clinical examination participants will be requested to complete the Copenhagen Hip and Groin Outcome Score (HAGOS). This is a patient-reported outcome measure, which quantifies a patient's current subjective perception of their hip and groin pain within the last week on six subscales, each with a score between 0 and 100. Additionally, participants will be requested to complete the Oslo Sports Trauma Research Center (OSTRC) overuse injury questionnaire with a focus on groin problems within the last week.

A standardized clinical examination will be performed. Palpation, resistance testing and stretching of affected muscle groups are used to categorize athletes into defined clinical entities. The pain reported by the athlete during the tests should also be felt in the affected structure. For example, in adductor-related groin pain, the pain on resisted adduction testing should reproduce the athlete's recognizable pain in the adductors. Pain felt in a different location-for example, the inguinal region on resisted adduction testing-would not signify adductor-related groin pain.

Statistical analyses Cohen's Kappa statistic (κ) is used to signify agreement between clinicians. Agreement was considered almost perfect if κ=0.81-1.00, moderate κ=0.41-0.60, substantial κ=0.61-0.80, fair κ=0.21-0.40, slight κ=0-0.20, and poor if κ<0. In addition, absolute agreement, prevalence, and bias index will be calculated. Statistical analyses will be performed using SPSS software.

Sample size With two examiners at each site, an expected Kappa of at least 0.8 with a lower limit of a 95% confidence interval of 0.4, and an expected prevalence between 0.3-0.7 for the three expected main defined clinical entities (adductor-related, inguinal-related, and iliopsoas-related groin pain), assuming no bias between examiners, the required sample size is determined to be 48 using a 2-tailed test. As pubic-related and hip-related groin pain is expected to be less frequent, a lower limit confidence interval of 0 for these entities is accepted, which in a 1-tailed test, maintaining an expected kappa of 0.8, requires a sample of only 10 participants. Thus 48 participants will be included.

Inclusion Criteria:

• adult (˃18y) male individuals regularly participating in recreational or elite sports activity (≥once/week).
• current primary complaint of hip and/or groin pain of a non-acute onset that worsens on exercise, or of acute onset, which has not recovered and become longstanding (˃6w).

Exclusion Criteria:

• any prior assessment or treatment from one of the examiners for the same complaints.
• fractures or acute injuries with severe pain were it would be unethical to examine the athlete twice.

Adult male individuals regularly participating in recreational or elite sports activity (≥once/week) with a current primary complaint of hip and/or groin pain of a non-acute onset that worsens on exercise, or of acute onset, which has not recovered and become longstanding (˃6w).

There is currently no plan of sharing individual participant data; however, upon reasonable request, anonymized data can be made available for interested parties.