Primary acute patellar dislocation (PAPD) is a common knee injury, particularly among adolescents and young adults, and is associated with variable risks of recurrent instability, osteochondral injury, and long-term patellofemoral degeneration. The aim of this narrative review was to summarize current evidence on the epidemiology, injury mechanisms, risk factors, diagnosis, emergency management, definitive treatment, complications, and prognosis of PAPD. A structured literature search was conducted in MEDLINE, Scopus, CINAHL, and Google Scholar from database inception to July 2025 using terms including patellar dislocation, acute patellar dislocation, primary patellar dislocation, first-time patellar dislocation, MPFL injury, risk factors, emergency management, treatment, and outcomes. Peer-reviewed studies, systematic reviews, meta-analyses, randomized trials, cohort studies, and clinical guidelines addressing acute first-time patellar dislocation were considered. Evidence was narratively synthesized across clinically relevant domains. Current literature supports a risk-stratified approach in which radiographs remain the first-line imaging modality after acute presentation or reduction, while MRI is useful for identifying osteochondral injuries, MPFL lesions, and anatomical risk factors. Conservative rehabilitation remains appropriate for low-risk first-time dislocations without major osteochondral injury or significant malalignment, whereas surgery may be considered in selected patients with displaced osteochondral fragments, loose bodies, persistent instability, or high-risk anatomy. Because available studies are heterogeneous and long-term evidence remains limited, further prospective research is required to refine patient selection and optimize treatment pathways.

The assessment of shoulder function remains challenging because static imaging and isolated clinical measures may not fully capture the behaviour of the shoulder complex during dynamic tasks. Instrumented biomechanical analysis provides quantitative information on shoulder kinematics, intersegmental coordination, kinetics, and neuromuscular activation; however, its clinical interpretation remains limited by task dependency, methodological variability, and the complexity of integrating multiple biomechanical outputs. This narrative review synthesizes foundational and contemporary literature on shoulder biomechanics during dynamic upper-limb tasks. Scapular-plane arm elevation is proposed as a pragmatic reference task, with shoulder motion represented through a normalized elevation cycle to provide a common temporal framework for interpretation. Biomechanical outputs are organized into complementary domains encompassing scapulothoracic and glenohumeral kinematics, intersegmental coordination, kinetics, and neuromuscular contribution. An integrated approach to the interpretation of shoulder biomechanics is presented, emphasizing the relationships among scapulothoracic and glenohumeral motion, their intersegmental coordination, and, when available, kinetic and neuromuscular information. Three recurrent functional phenotypes are described: altered scapular contribution, compensatory trunk–shoulder strategies and altered humeral axial rotation coupling. The value of shoulder biomechanical assessment lies in the integrated interpretation of movement patterns rather than in isolated variables. This multidimensional perspective provides a framework for translating biomechanical data into functionally meaningful information for clinics and research.