## 4 Discussion  
The aim of the current clinical laboratory-based study was to examine the effect of 8 weeks of individualized CEP on postural and musculoskeletal asymmetries in young soccer players. According to the authors' knowledge, this is the first study that has examined the effect of individual specific intervention programs in an attempt to improve the overall musculoskeletal health of young soccer players by individually correcting their postural asymmetries. The main findings of the current study were the significant corrections in several of the tested asymmetries (such as the ATR (A), the 90-90 test for hamstring flexibility, the external and internal hip rotation, the Stork Test, the Thomas test, and the ankle prone passive dorsiflexion) following the application of the intervention programs. These results suggest that 8 weeks of an individual CEP program may improve postural and musculoskeletal asymmetry statuses in young male soccer players. Considering that postural asymmetries may induce injury development [1; 2; 3; 4; 5; 6] and a reduction in exercise performance in young soccer players [7], they should be regularly screened for postural and musculoskeletal asymmetries for an early diagnosis and a primary correction purpose. In the current study, the ATR (A) results demonstrated a statistically significant improvement with a large effect size, following the application of the intervention programs. In mild scoliosis, the main goal of exercise intervention applications is to decrease the progression of the scoliosis curvature [38], while the same intervention has been used as the only treatment for severe adolescent idiopathic scoliosis as well [39]. In our study, most of the participants observed were in the functional scoliosis range, and individualized CEP interventions were able to improve their functional scoliosis curvature. Our results support a previous study suggesting that scoliotic posture and/or non-structural scoliosis are impermanent and reversible [40]. There was also improvement in the co-existing spine asymmetries, such as thoracic kyphosis or lumbar lordosis, results that are in agreement with a previous report [41], although in this previous study the frequency was everyday treatment under direct supervision, for 30 to 60 min, and lasted for three months in junior soccer players. However, only 8 weeks of CEP intervention may induce similar results in young soccer players. Interestingly, no significant improvement was found in the results of thoracic kyphosis or lumbar lordosis following the intervention program, which is not in agreement with the study of [PERSON] et al. (2014). In our study, the suggested frequency of the intervention program was twice a week and lasted for 8 weeks. However, in the study of [PERSON] et al. (2014), the intervention period lasted for six months and the hold during stretching  
Figure 4: Hurdle Test: pre- and post-intervention results, \(\hat{\gamma}=\) effect size. and rest periods between sets was not more than 5 s. Thus, the total time of the stretching sessions in both groups was 10-15 min, resulting in 40-65 min per week [3]. Similar to our study, holding during the stretching exercises started with 5 s, but progressively increased, resulting in 7-12 min per stretching program and a total of 14-24 min per week per program, a frequency much less than one used in the study of [PERSON] et al. (2014). Likewise, stretching exercises were used for lower body muscle tightness which decreased involved joints' ROM, and combined with strengthening exercises targeting the weak muscles, resulted in an improved muscle balance and postural asymmetries [3]. Consequently, a greater training frequency when combined with a longer-training intervention period, such as the one used in a previous study ([PERSON] et al. 2014), might possibly contribute to further improving thoracic kyphosis and lumbar lordosis. During the 8-week intervention program, there was a statistically significant increase in standing and sitting height and in body mass results as well.