Left or right - the development of handedness and its significance in everyday hand surgery

Handedness describes the preference for using one hand over the other in fine and gross motor tasks and represents a key manifestation of functional brain asymmetry. Around 90% of the world's population is right-handed. The development of handedness is based on a complex interplay of genetic, epigenetic, neurobiological, developmental psychological and environmental factors. Prenatal movement patterns allow conclusions to be drawn about future handedness at an early stage. However, genetic influences explain only part of the variance, meaning that polygenic and regulatory mechanisms, as well as perinatal and postnatal influences, contribute significantly to the development and stabilisation of handedness. Handedness has considerable clinical relevance for hand surgery. Injuries to the dominant hand frequently lead to greater subjective limitations, longer rehabilitation and a greater impairment of work capacity and quality of life. At the same time, cortical plasticity offers the possibility for adaptive processes. Taking handedness into account therefore influences the assessment of severity, the choice of treatment strategies, the definition of rehabilitation goals, and the interpretation of patient-reported outcomes. Occupational health aspects are also relevant, as left-handed individuals in right-handed-dominated environments have an increased risk of certain strain and compression syndromes. Furthermore, handedness is relevant not only in patients but also in surgeons, for example with regard to instrumentation, training conditions and bimanual coordination. The aim of this review is to bring together the neurobiological and developmental foundations of handedness and to critically examine their significance for diagnosis, treatment planning, rehabilitation and clinical decision-making processes in hand surgery. An integrative understanding of handedness can help to differentiate treatment strategies more functionally and to optimise them in a patient-centred and scientifically sound manner.