Studies in Sport Medicine

The Effect of Eight Weeks Reactive Neuromuscular Training on Balance and Genu Valgum of 8–12-Year-Old Students

Document Type : Research Paper

Authors

Faezeh Karimzadeh jazy 1
Nader Rahnama 2

1 Master of Corrective Exercise and Sport Injuries, Faculty of Sport Sciences, University of Isfahan, Isfahan, Iran

2 Full Professor, Department of Sport Injuries, Faculty of Sport Sciences, University of Isfahan, Isfahan, Iran

https://doi.org/10.22089/smj.2025.16715.1746
Abstract
 
The knee joint, one of the most complex and essential joints in the lower limb, is particularly susceptible to postural abnormalities, with Genu Valgum being among the most prevalent. Individuals with Genu Valgum exhibit knees positioned close together, external tibial rotation, and internal femoral rotation. These biomechanical alterations may contribute to balance impairments. Given that specific training interventions may improve both the deformity and functional performance, this study aimed to evaluate the effect of reactive neuromuscular training (RNT) on the degree of Genu Valgum as well as static and dynamic balance in female students.
Methods
This applied quasi-experimental study was conducted as part of a master’s thesis in Corrective Exercise and Sport Injuries. The study population included female students aged 8–12 years from schools located in District 6 of Isfahan. Based on statistical power considerations and G*Power software recommendations, a sample of 30 individuals diagnosed with Genu Valgum was selected and randomly allocated into two groups of 15: experimental and control.
Inclusion criteria included: age 8–12 years, absence of lower limb injuries in the preceding year, no ongoing pain or history of surgery in the lower limbs, equal leg lengths, voluntary participation with informed consent, and no use of orthotic insoles. Exclusion criteria were withdrawal from the study, missing more than three consecutive or five nonconsecutive training sessions, and any injury precluding protocol completion or participation in post-testing. All participants provided informed consent before the study.
Anthropometric data, age, height, weight, actual leg lengths, and inter-malleolar distance  were measured. Height and leg length were measured using a wall-mounted tape accurate to 1 cm; weight was recorded with a Breuer digital scale; the inter-malleolar distance was assessed with a caliper.
Dominant foot was determined by two methods: (1) instructing the participant to kick a soccer ball toward a one-meter-wide goal at 10 meters distance with moderate power and maximal accuracy, with the kicking foot classified as dominant; (2) self-report confirmation.
Dynamic balance was assessed using the Star Excursion Balance Test, whereas static balance was evaluated via the Stork Balance Test. Following pre-testing, the experimental group underwent an eight-week selective reactive neuromuscular training program, while the control group received no intervention. Post-testing replicated baseline assessments.
 
Results
Static balance: Repeated measures ANOVA revealed significant improvement in static balance post-intervention for both groups, with the experimental group demonstrating significantly greater gains than controls (p < 0.05).
Dynamic balance: Analysis of Star Excursion Balance Test results indicated significant improvements after eight weeks of RNT in the anterior, anterolateral, and posterior directions compared to control (p < 0.05). No significant changes were found in anteromedial, posteromedial, posterolateral, lateral, or medial directions.
Genu Valgum: Cross-knee distance analyses showed an increase in the control group from pre- to post-test, whereas the experimental group exhibited a decrease post-intervention. Time and interaction effects were statistically significant (p < 0.001), while the between-group effect was non-significant (p > 0.05).
 
Table1- Mean and standard deviation of research variables by groups





Variable


Groups


Pre-test
Mean and standard deviation


Post-test mean and standard deviation




Static balance (Stork test)
(Sec)


Control


33/0 ± 14/4


45/9 ± 15/3




Experimental


36/8 ± 17/2


73/5 ± 27/2




Anterior dynamic balance
(Cm)


Control


96/8± 12/8


100/2 ± 12/6




Experimental


89/0 ± 12/1


103/0 ± 9/5




Anterior medial Dynamic balance (Cm)


Control


95/4 ± 16/6


98/0 ± 17/4




Experimental


86/5 ± 13/5


90/8 ± 14/8




Anterior external Dynamic balance (Cm)


Control


92/6 ± 13/7


95/7 ± 12/8




Experimental


83/9 ± 11/0


104/9 ± 11/2




Posterior dynamic balance
(Cm)


Control


81/0 ± 12/5


83/9 ± 11/3




Experimental


73/4 ± 8/7


87/6 ± 9/1




Posterior medial dynamic balance (Cm)


Control


81/0 ± 11/1


83/3 ± 11/5




Experimental


79/2 ± 15/6


84/2 ± 16/7




Posterior external dynamic balance (Cm)


Control


86/7 ± 15/3


187/8 ± 10/7




Experimental


78/6 ± 13/8


87/4 ± 10/7




 Medial dynamic balance
(Cm)


Control


78/4 ± 14/6


81/5 ± 16/7




Experimental


75/5 ± 20/4


76/2 ± 19/8




External dynamic balance
(Cm)


Control


83/0 ± 24/0


91/2 ± 13/9




Experimental


74/2 ± 18/3


85/2 ± 9/0




Amount of Genu Valgum
(Inner ankle distance)
 (Cm)


Control


6/9 ± 1/5


7/1 ± 1/6




Experimental


8/2 ± 1/5


6/5 ± 1/2
 





 
Conclusion
This study evaluated the effects of an eight-week reactive neuromuscular training on Genu Valgum and balance performance. RNT exercises, such as linear lunges with Thera Band elastic resistance, impose controlled perturbations that enhance stability and static balance. Improved strength across the lumbar-pelvic-femoral kinetic chain and enhanced proprioception contributed to superior test performance. These findings concur with Kim et al. (2012), who documented balance improvements following eight weeks of RNT (8), and Mirzaei et al. (2020), who reported improved dynamic balance in women with dynamic knee valgus after a single RNT session (4).
RNT promotes correct movement patterns via active error detection and feedback, facilitating dynamic muscular stability and limiting abnormal joint motions. Elastic resistance in these exercises is utilized not for strength gains per se but to provide tension cues emphasizing proper body positioning and control during movement (33, 34, 22). Such interventions have been employed successfully to restore functional stability in injured athletes (22).
Melinda Pittman (2013) studied the impact of RNT on knee biomechanics in 29 women, demonstrating increased landing stability and reduced dynamic valgus after eight weeks of RNT. She concluded that pre-sport specific RNT improves performance and diminishes anterior cruciate ligament injury risk in individuals exhibiting valgus at landing (35). The present results align closely with Pittman’s study, as the training targeted valgus control in frontal and sagittal planes.
Article Message
Based on this study’s findings, reactive neuromuscular exercises effectively reduce Genu Valgum and improve balance. It is recommended these exercises be integrated into corrective exercise programs for students with musculoskeletal dysfunctions.
Ethical Considerations
This study was conducted under the supervision of the Ethics Committee of the University of Isfahan, with approval code IR.UI.REC.1402.093 (https://ethics.research.ac.ir/EthicsProposalView.php?&code=IR.UI.REC.1402.093).
Authors’ Contributions
Conceptualization, data collection, data analysis, and manuscript writing were performed by Faezeh Karimzadeh. Review and editing were conducted by Dr. Nader Rahnama, who also served as project manager and responsible author. Literature review was contributed by Karimzadeh, Rahnama, and Dr. M. Namazizadeh.
Conflict of Interest
The authors declare no conflicts of interest.
 
Acknowledgments
This research derives from Faezeh Karimzadeh’s master’s thesis, supervised by Dr. Nader Rahnama. The authors express sincere gratitude to all who supported and participated in this study.
 

Keywords

Reactive Neuromuscular Training, Genu Valgum, Balance, Female Students

Subjects

 
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Studies in Sport Medicine
Volume 17, Issue 44
Spring 2025
Pages 17-32

  • Receive Date 19 June 2024
  • Revise Date 24 December 2024
  • Accept Date 02 February 2025

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