The Effect of Dynamic Neuromuscular Stability (DNS) Exercises on Knee Functional ‎Tests in Female Athletes

Abstract

Purpose: Strengthening and improving neuromuscular control in various ways, including technique modification, in order to prevent sports injuries, as a principle, is always of interest to researchers and athletes. Landing technique after jumping during sports such as volleyball is known as one of the most important non-contact mechanisms of knee joint ligament injury. The purpose of this study was to investigate the effect of dynamic neuromuscular stability (DNS) exercises on knee functional tests in female athletes. Methods: 30 female volleyball players (age 22.06±3.39 years, height 1.67±0.04 m, weight 63.70±8.86 kg and body mass index 22.81±3.38 kg/m2) with at least three years of experience in volleyball training, they participated in this research and were randomly divided into two control groups (15 people) and an experimental group (15 people). Tuck Jump and Landing Error Scoring System (LESS) tests were recorded as subjects' performance scores. The kinematic variables of the subjects' lower limbs were measured by two cameras from the sagittal and frontal views during the Tuck Jump and LESS tests, before and after DNS exercises. The functional error of the subjects was recorded using the Kinovea software and recorded in the special table for scoring the tests. The subjects of the experimental group participated in the program of DNS exercises for 6 weeks and 3 sessions per week (each session lasting about 50 minutes). In order to analyze the data, independent and dependent parametric t-tests were used for data with normal distribution, and Mann Whitney U and Wilcoxon non-parametric tests were used for data with non-normal distribution in SPSS version 23 software. Results: The findings of the current research showed that DNS exercises was led to a significant decrease in the average Tuck Jump errors from 10.66 in the pre-test to 7.80 in the post-test (p=0.001), the score of the LESS from 8.13 in the pre-test to 4.53 in the post-test (p=-0.001) and the ligament dominance score decreased from 1.40 in the pre-test to 0.8 in the post-test (p=0.003) in the experimental group. Conclusion: According to the results of the present study, it seems that performing DNS exercises in female volleyball players reduces the risk of injury and improves Motor-performance and is probably effective in the rehabilitation of athletes. Therefore, the use of DNS exercises in sports with frequent jumps and landings such as volleyball is recommended to prevent ACL injury.

Keywords

• female athletes
• tuck jump
• landing error scoring system
• anterior cruciate ligament‎