Abstract
Background & Objectives: Motor performance deficit is one of the main causes of musculoskeletal injuries. It is caused by dynamic postural instability, a dynamic neuromuscular defect. On the other hand, preventing musculoskeletal injuries is a major challenge in studies of physical activity. Therefore, if dynamic postural stability and functional movement defects are considered the main causes of injuries of internal origin, it is likely that various injuries can be prevented by improving postural stability through participation in functional movement correction exercises and basic skills. Preventing skeletal–muscular injuries is the main challenge in sports science research; accordingly, internal risk factors cause more than 70% of musculoskeletal injuries. Some studies have shown that defects in motor performance are among the main causes of endogenous injuries, which are themselves caused by instability in dynamic body posture. This study investigated the effect of dynamic neuromuscular stability (DNS) exercises on landing error scoring system (LESS) and single–leg squat test scores in athletic male students.
Methods: The study employs a quasi–experimental design with a pretest–posttest and control group. A total of 40 male secondary school students from physical education schools in the educational districts of Mashhad City, Iran, served as the research sample. They were randomly assigned to the experimental group (20 people) and the control group (20 people). The inclusion criteria for the subjects in the study were as follows: being 16–18 years old, having a history of 2–3 years of regular exercise, not suffering from musculoskeletal disorders, lacking any medical contraindications to performing the exercises, and not having had any injuries in the six months before the start of the study. The exclusion criteria for the study included not participating in two consecutive or three alternating exercise sessions and voluntarily withdrawing from further participation. Before and after the training intervention, the scores for the Single Leg Squat Test and the Landing Error Scoring System (LESS) were evaluated. The experimental group performed dynamic neuromuscular stability exercises for 6 weeks (3 sessions per week, 45 to 60 minutes per session), while the control group received no intervention. The exercises of retaining DNS patterns and transferring from one pattern to another were performed in the order of their occurrence in the baby and by degree of difficulty, while simultaneously teaching, correcting, and practicing deep breathing in all patterns for about 40 minutes. Exercises included diaphragmatic breathing, lying on the back 90–90, lying on the stomach, rolling over, sitting on the side, sitting on an incline, tripod, kneeling, squatting, and standing up. Descriptive (mean and standard deviation) and inferential (analysis of covariance) statistics were used to analyze the data in SPSS version 26, with a significance level of 0.05.
Results: After 6 weeks of DNS exercises, there was a significant and positive difference in single–leg squat test scores (p<0.001) and single–leg landing test scores (p<0.001) in the experimental group compared to the control group. Also, the eta–squared values for the single–leg squat test score (45.2%) and single–leg landing test score (67.7%) indicated the moderate effectiveness of dynamic neuromuscular stability exercises.
Conclusion: Considering the study's results showing the effectiveness of dynamic neuromuscular stability (DNS) exercises in improving the single–leg squat test and single–leg landing test, it is recommended that the DNS exercises used in the present study be incorporated alongside other methods during the preparation stages for young people in physical education schools.