## 1 Introduction  
Throwing ability, once crucial for human survival through protection and predation [1], has evolved into a skill primarily utilized in sports and recreational activities. Despite its reduced survival importance, throwing remains a significant human function, albeit one not commonly assessed in clinical practice. Rotator cuff-related shoulder pain (RCRSP) is a comprehensive term encompassing involvement of the rotator cuff muscles, tendons, and surrounding tissues, including the bursae, bone, ligament, capsule, nerve, and associated vascular structures [2; 3]. This terminology acknowledges the complexity of pain science and recognizes that the precise source of symptoms is often indeterminate. RCRSP represents the most prevalent musculoskeletal shoulder condition, typically manifesting as shoulder pain and weakness, particularly during shoulder elevation and external rotation [2]. A characteristic feature of RCRSP is reduced upper-body muscle performance [4; 5; 6], which can adversely impact valued activities involving lifting, carrying, pulling, pushing, and throwing [2]. Consequently, evaluating shoulder muscle performance in a functional manner may hold clinical significance [7]. The clinical implementation of functional tests that assess shoulder muscle performance holds particular relevance in several contexts. First, these tests can provide objective measures of functional capacity that complement traditional clinical examinations. Unlike isolated muscle testing or range of motion assessment, functional tests can evaluate the integrated performance of the upper extremity, offering insights into how RCRSP affects daily activities and occupational tasks. Second, when selecting appropriate interventions and monitoring progress, clinicians need reliable tools that can quantify functional improvements without exacerbating symptoms [7]. While functional upper extremity tests exist, including the push-up, pull-up, Y-Balance Test-Upper Quarter, and Closed Kinetic Chain Upper Extremity Test, these are performed in closed kinetic chain positions (where the distal segment is fixed and the proximal segment moves, typically with the hand or forearm fixed against a surface) [8; 9]. Many daily shoulder activities, however, occur in an open kinetic chain, where the distal segment moves freely through space while the proximal segment remains relatively fixed, such as reaching, lifting, or throwing movements. The Shoulder Performance Activity Test (SPAT) evaluates open kinetic chain shoulder tasks but does not assess strength or power [10]. There is thus a need for a functional test that is clinically feasible, measures the strength and power performance of the shoulder girdle, and is conducted in an open kinematic chain. The seated medicine ball throw (SMBT) and unilateral shot-put test (ULSPT) are open-chain throwing tests designed to measure functional muscle performance [8; 9; 11; 12]. These tests have primarily been utilized in overhead and upper extremity sports populations to quantify the distance of a chest pass or shot-put throw performed in a seated position, minimizing energy transfer from the lower body [11; 13] (Figures 1 and 2). Previous research has demonstrated good test-retest reliability of the SMBT in asymptomatic older adults (mean age = 72.24 \(\pm\) 5.2 years; ICC = 0.994, r = 0.73-0.77) [14]. The SMBT has also shown moderate to strong correlations with 'gold standard' isokinetic shoulder and elbow strength in young overhead athletes (age = 21.6 \(\pm\) 2.5 years; r = 0.595-0.803) [8]. Normative throwing distance data has been reported for three age groups in volleyball, handball, and tennis [11]. The ULSPT has demonstrated excellent reliability (ICC = 0.988 dominant, 0.971 non-dominant side) in asymptomatic recreationally active adults [9]. Moderate to high associations have been reported between ULSPT and isokinetic pushing peak forces (r = 0.75-0.87) [15].