Normalized STEAM-based diffusion tensor imaging provides a robust assessment of muscle tears in football players: preliminary results of a new approach to evaluate muscle injuries

Objectives: To assess acute muscle tears in professional football players by diffusion tensor imaging (DTI) and evaluate the impact of normalization of data. Methods: Eight football players with acute lower limb muscle tears were examined. DTI metrics of the injured muscle and corresponding healthy contralateral muscle and of ROIs drawn in muscle tears (ROItear) in the corresponding healthy contralateral muscle (ROIhc_t) in a healthy area ipsilateral to the injury (ROIhi) and in a corresponding contralateral area (ROIhc_i) were compared. The same comparison was performed for ratios of the injured (ROItear/ROIhi) and contralateral sides (ROIhc_t/ROIhc_i). ANOVA, Bonferroni corrected post-hoc and Students t-tests were used. Results: Analyses of the entire muscle did not show any differences (p>0.05 each) except for axial diffusivity (AD; p=0.048). ROItear showed higher mean diffusivity (MD) and AD than ROIhc_t (p<0.05). Fractional anisotropy (FA) was lower in ROItear than in ROIhi and ROIhc_t (p<0.05). Radial diffusivity (RD) was higher in ROItear than in any other ROI (p<0.05). Ratios revealed higher MD and RD and lower FA and reduced number and length of fibre tracts on the injured side (p<0.05 each). Conclusions: DTI allowed a robust assessment of muscle tears in athletes especially after normalization to healthy muscle tissue. Key Points STEAM-based DTI allows the investigation of muscle tears affecting professional football players. Fractional anisotropy and mean diffusivity differ between injured and healthy muscle areas. Only normalized data show differences of fibre tracking metrics in muscle tears. The normalization of DTI-metrics enables a more robust characterization of muscle tears.(VLID)475075

The effects of an 8-week multicomponent inpatient treatment program on body composition and anaerobic fitness in overweight and obese children and adolescents

BACKGROUND: High intensity exercise is considered as an effective means for reducing body fat. The aims of the present study were to investigate (1) whether body mass would be lost and body composition would change and (2) whether variables of anaerobic fitness prior to the intervention period would be related to loss of body mass and changes in body composition in overweight and obese children and adolescents. METHODS: A total of 28 children and adolescents (19 boys, 9 girls) attended an 8-week multicomponent inpatient program. Caloric intake was based on the subject's weight and a daily energy deficit of ~500 kcal was targeted. At the beginning and at the end of the program, variables of anaerobic fitness were assessed using Wingate tests. Body composition was measured before and after the program using dual-energy X-ray absorptiometry. RESULTS: Body mass decreased by 11.4% ± 1.6% in boys and by 11.0% ± 2.8% in girls (P 0.05). The decrease in body mass and the decrease in fat mass were neither associated with overall energy expenditure nor with the energy deficit in both genders (P > 0.05). Mean power in W/kg increased in the Wingate tests by 95.4% ± 109.1% in boys and by 100.0% ± 119.9% in girls (P < 0.001). CONCLUSIONS: Adjustments of the chronically positive imbalance of energy intake and energy expenditure of obese children and adolescents living in obesogenic environments should be addressed in a multisectoral approach. Future research in multicomponent childhood and adolescent weight loss programs should be directed towards a better understanding of the underlying complex dynamics in energy homeostasis which promote weight loss and changes in body composition due to high intensity exercise interventions