Introduction
Musculoskeletal disorders (MSDs) in the upper extremities have a high prevalence globally, especially among workers ( Govaerts et al., 2021 ) and athletes ( Lehman et al., 2020 ). Because humans are so dependent on their hands, MSDs in the upper extremities often cause greater disability and reduced health-related quality of life compared to other body regions ( de Putter et al., 2014 ). These conditions can prevent normal functioning in daily activities, especially when the dominant wrist and hand are affected ( Jayakumar et al., 2018 ). Additionally, MSDs in the upper extremities are robustly associated with high costs related to healthcare services and lost productivity ( de Putter et al., 2012 ).

Professionals involved in the rehabilitation process face challenges in determining when an athlete or a worker with upper limb MSDs is ready to return to training ( Oak et al., 2022 ) or work ( Hosseininejad et al., 2023 ), respectively. Physical demands on the upper limb often require preserved functional properties such as strength, movement amplitude, and dexterity, as well as normal pain sensitivity. For example, it is well known that the sensation of tissue tightness or pain can limit sports or work performance ( Barr, Barbe & Clark, 2004 ). Therefore, a comprehensive and easily applicable assessment of objective measures of pain sensitivity and physical performance holds great potential in improving current rehabilitation practices. However, tests composing multimodal assessment protocols are usually conducted in different study samples, impeding comparison between tests’ reliability ( Llanos et al., 2021 ; Schrama et al., 2014 ). Furthermore, one of the challenges in the repeated assessment of physical performance tests is the presence of learning effects and/or skill improvement in the technical execution of the tasks ( Tsigilis & Theodosiou, 2008 ), which likely varies between the dominant and non-dominant sides ( Stöckel & Weigelt, 2012 ). For example, the non-dominant side may have a greater learning potential, which can skew asymmetry indices with repeated assessments over time. This effect is particularly problematic in the context of rehabilitation, as it can lead to false indications of improvement that may not genuinely exist or be insignificant. To address this issue, rehabilitation professionals commonly perform bilateral assessments of both limbs during various musculoskeletal examinations ( Walker, Hall & Hurst, 1990 ). This approach allows rehabilitation professionals to determine the presence of a relevant imbalance or discrepancy between the two sides, providing valuable insights into the subject’s condition ( Jones, 2019 ), especially when beyond the normal asymmetries within a reasonable range of 10% ( Evershed, Burkett & Mellifont, 2014 ). However, despite the widespread use of asymmetry assessment, the reliability of such an approach has not been well explored. In this sense, assuring the reliability of any assessment procedure is essential for its implementation in clinical and research practices ( Kimberlin & Winterstein, 2008 ).

This study aimed to evaluate the reliability of a range of easy-to-implement procedures assessing muscle mechanical properties, manual dexterity, pressure pain thresholds, active range of motion, and maximal isometric strength of the upper limbs in terms of absolute values and asymmetries between both sides. Furthermore, the correlations between the different assessment procedures were explored as a secondary aim to determine the interrelationship between tests.