# Sport-Specific Abdominal Wall Muscle Differences:
## 1 Introduction  
Athletic performance and susceptibility to sport-related injuries are deeply influenced by the specific physical demands and training regimens associated with different sports. This issue is particularly evident in team sports such as soccer and basketball, where players exhibit different physical and physiological features shaped by the unique requirements of each sport. Both types of players need to achieve high physical conditioning levels to provide specific training adaptations [1].  
In this line, soccer and basketball impose different demands on athletes; for example, soccer involves continuous play with intermittent bursts of high-intensity activity, necessitating endurance, agility, and a robust core for effective ball and control kicking [2]. In contrast, basketball requires frequent, intense short bursts of activity during the game such as repeated jumping, sprinting, and quick changes in directions, thus demanding high levels of explosive strength and core stability to support these movements [3].  
Abdominal wall muscle strength and morphology, especially the abdominal wall thickness, play a crucial role in not just the players' performance but also in the prevention and management of injuries [4; 5].  
A strong and stable core reduces the injury risk by maintaining an appropriate alignment and function of the pelvis, hips, and lower spine during sports activities [6; 7; 8]. This is supported by studies showing that the cross-sectional area (CSA) and thickness of the multifidus muscle could be increased by activating this muscle, progressing from motor control to increased static and dynamic balance [9]. This protective feature of the abdominal wall muscles plays an important role given the high incidence of lower limb and low back injuries in sports like soccer and basketball [10]. Furthermore, differences in these muscles--such as the transversus abdominis (TrAb), internal oblique (IO), external oblique (EO), and rectus abdominis (RA)--may indicate variations in muscle function and injury risk between athletes from different disciplines [11; 12; 13].  
Ultrasound imaging (USI) has emerged as an essential technique in evaluating the morphology of the abdominal wall muscles due to its reliability and validity, in static and dynamic modes [14; 15]. This imaging modality allows for the precise measurement of muscle thickness or CSA and could detect changes in muscle size and structure with excellent intra- and inter-rater reliability [14; 15].  
USI studies that focus on the sports context have demonstrated its efficacy in assessing core muscles in athletes. For instance, research involving basketball players has shown significant differences in the thickness of the abdominal muscles when compared in elite and amateur athletes [16]. In this line, in soccer players, ultrasonography has been used to assess muscle adaptations and has proven effective in monitoring muscle changes over training periods, thus aiding in the development of targeted training programs [17].  
The aim of the present study was to investigate the thickness differences in abdominal wall muscles--EO, IO, TrAb, RA and inter-recti distance (IRD)--between amateur soccer and basketball players by USI, providing a comparative analysis that could inform more tailored and injury prevention programs. This research not only adds to the existing literature by providing detailed morphological data on core muscles specific to these sports but also explores the implications of these differences for athletic training and performance.