Soccer is a laterally dominant sport owing to the repetitive nature of unilateral kicking. The relationship between functional and body composition asymmetries related to limb dominance in soccer players has yet to be established. When present, asymmetries can increase the risk of injury and low back pain. Our study investigated whether lateral dominance is associated with limb asymmetries in a comprehensive body composition assessment among varsity soccer players. Twenty-seven varsity soccer players (age 20.4 ± 1.7 years old; BMI 22.6 ± 4.6 kg/m²) participated in this study. Body composition was assessed through dual-energy X-ray absorptiometry scans. Results showed low lower limb asymmetry indices in both males (3.82%) and females (3.36%) compared to normal ranges. However, upper limb lean mass exhibited high asymmetry, surpassing thresholds in males (7.3%) and females (4.39%). Significant differences were found in total bone mass among males and total lean body mass among females. Male players exhibited higher asymmetry indices in both arm and trunk mass compared to females. Despite these asymmetries, no significant correlations were found between asymmetry indices and occurrences of lower limb injury or low back pain. The study suggests that while evaluating body composition for injury prevention in soccer shows potential, lateral dominance may be influenced by factors extending beyond sport-specific adaptations.

Background: Low back pain (LBP) is one of the most disabling diseases and a major health issue. Despite the evidence of a link between paraspinal and gluteal muscle dysfunction and LBP, it is unknown whether aquatic exercises can lead to improvements in paraspinal and gluteal muscle morphology and function, and whether improvements in overall muscle health are associated with improvements in patients’ outcomes. The unique properties of water allow a water-based exercise program to be tailored to the needs of those suffering from LBP. This study uses magnetic resonance imaging (MRI) to investigate the effect of an aquatic exercise program versus standard exercise on 1) paraspinal and gluteal muscle size, quality and strength and 2) pain, disability, and psychological factors (pain related fear, depression, anxiety, sleep quality) in chronic LBP. Methods: This study will include 34 participants with chronic non-specific LBP and moderate to severe disability, aged between 18 and 65, who will be randomly assigned (1:1) to the aquatic exercise group or land-based standard care exercise group. Both groups will receive 20 supervised sessions, twice per week over 10 weeks. MRIs will be obtained along the lumbosacral spine (L1-L5) and pelvis at the start and end of the intervention to assess the effect of each exercise intervention on paraspinal and gluteal muscle size and quality. Pre- to post-intervention changes in all outcomes between each group will be assessed, and the association between the changes in back muscle quality and clinical outcomes will be examined. Between-subjects repeated measure analysis of variance will be used to examine the changes in paraspinal muscle morphology over the different time points. Linear mixed models will be used to assess whether baseline scores can modify the response to the exercise therapy treatment. Discussion: This study will determine if water-based exercises targeting the lower back and gluteal muscles can lead to important changes in muscle quality and function, and their possible relation with patients’ pain and functional improvements. Our findings will have strong clinical implications and provide preliminary data to design a community program to better support individuals with chronic LBP. Trial registration: NCT05823857, registered prospectively on April 27^th, 2023.

The Child-Focused Injury Risk Screening Tool (ChildFIRST) assesses movement competence in children and currently uses a dichotomous scoring scale, which, while simple and practical, may lack the precision needed for nuanced movement skill analysis. This study compared the inter- and intra-rater reliability of the ChildFIRST when scored using a dichotomous scale versus a seven-point Likert scale. Fourteen trained raters evaluated video recordings of eight children performing ten standardized movement tasks using both scales across two sessions. Reliability was assessed using intraclass correlation coefficients (ICCs). The dichotomous scale demonstrated moderate to excellent inter-rater reliability (ICC = 0.50–1.00) and good to excellent intra-rater reliability (ICC = 0.75–1.00). The seven-point scale showed similar inter-rater reliability but generally lower intra-rater reliability (ICC = 0.50–1.00). In addition, raters preferred the dichotomous scale in terms of practicality (91.6%), feasibility (75%), and overall usability (66.6%). These findings suggest that while both scales provide comparable inter-rater agreement, the dichotomous format offers greater consistency across repeated ratings and is more favorably received by users. The dichotomous scoring system is therefore recommended for continued use in field-based screening and future applications of the ChildFIRST.