Background: Obesity negatively affects balance and core muscles playing a crucial role in postural stability. However, little is known about the relationship between abdominal muscle thickness and balance in normal weight women. Objectives: This study aimed to investigate the relationship between abdominal muscle thickness and balance ability in normal-weight women in their 20s. Design: Cross-sectional observational study. Methods: Twenty-four healthy normal-weight women participated. Abdominal muscle thickness including the external oblique (EO), internal oblique (IO), and transverse abdominis (TrA) was measured by ultrasonography. Static balance was assessed during the One-leg standing test and Tetrax system, while dynamic balance was assessed using the Y-Balance and single leg triple hop tests. Pearson correlation analysis was conducted to examine the relationship between muscle thickness and balance performance. Results: IO thickness showed a negative correlation with static balance (r=- .42). EO thickness showed a positive correlation with single leg triple hop tests (r=.49-.58) and a negative correlation with posterolateral distance during YBalance test. Conclusion: Our findings suggested that abdominal muscles, specifically the IO and EO, are moderately related to balance performance in normal-weight young women. These findings demonstrated the potential benefit of targeted core strengthening interventions to improve postural stability and functional movement. Further studies involving additional muscles and diverse populations are recommended.

INTRODUCTION
SUBJECTS AND METHODS
    Study Design
    Outcome Measures
    Data and Statistical Analysis
RESULTS
    Abdominal muscle thickness
    Correlation between balance and abdominal muscle
DISCUSSION
CONCLUSION
REFERENCES

• Hwanhee Lee(Department of Physical therapy, Sunmoon University, Cheonan, Republic of Korea)
• Seowon Moon(Department of Physical therapy, Sunmoon University, Cheonan, Republic of Korea)
• Dongyeop Lee(Department of Physical therapy, Sunmoon University, Cheonan, Republic of Korea)
• Jaeho Yu(Department of Physical therapy, Sunmoon University, Cheonan, Republic of Korea)
• Jinseop Kim(Department of Physical therapy, Sunmoon University, Cheonan, Republic of Korea)
• Yeongyo Nam(Department of Physical therapy, Sunmoon University, Cheonan, Republic of Korea)
• Jonggeun Woo(Department of Physical therapy, Sunmoon University, Cheonan, Republic of Korea)
• Jiheon Hong(Department of Physical therapy, Sunmoon University, Cheonan, Republic of Korea, Digital Healthcare Institute, Sunmoon University, Cheonan, Republic of Korea) Corresponding author