Background: Single-leg squat (SLS) is widely used for assessing lower extremity (LE) function. Although abnormal kinematics and foot pressure distribution (FPD) are key indicators of dysfunction, the relation between specific LE kinematic patterns and FPD during SLS remains under investigated. Objects: This study aimed to investigate the correlations among LE kinematics specifically the dynamic knee valgus angle (DKVA), knee inward distance (KID), hip outward distance (HOD) and FPD (hallux, medial, central, and lateral forefoot [FF]) during SLS. Methods: Thirty healthy participants performed SLS on their dominant leg. LE kinematics were analyzed using two-dimensional video analysis to determine DKVA, KID, and HOD. FPD was recorded using the Zebris FDM and analyzed across four regions (hallux, medial, central, and lateral parts of the FF). Pearson correlation coefficients were used to determine the relationships between LE kinematics and FPD. Results: Pearson correlation analysis revealed that hallux pressure was significant associated with the extent of KID (r = 0.547, p = 0.002). In addition, a moderate positive correlation was found between HOD and FF lateral (r = 0.406, p = 0.026), indicating that lateral pelvis displacement contributes to higher FF lateral loading. However, DKVA, which is conventionally used to assess LE kinematic variables, showed no significant association with FPD. Conclusion: This study identified significant relationship between specific kinematic variables (KID and HOD) and FPD (hallux and FF lateral), however, relationship between DKVA and FPD was not observed. Consequently, it is necessary to separately evaluate joint-specific kinematics, such as KID and HOD, to determine their distinct associations with FPD.

INTRODUCTION
MATERIALS AND METHODS
    1. Participants
    2. Procedure
    3. Foot Pressure Distribution
    4. Lower Extremity Kinematics
    5. Statistical Analysis
RESULTS
DISCUSSION
CONCLUSIONS
FUNDING
ACKNOWLEDGEMENTS
CONFLICTS OF INTEREST
AUTHOR CONTRIBUTIONS
ORCID
REFERENCES

• Il-kyu Ahn(Department of Physical Therapy, The Graduate School, Yonsei University, Department of Physical Therapy, Kinetic Ergocise Based on Movement Analysis Laboratory, Yonsei University)
• Ha-yeong Baek(Department of Physical Therapy, The Graduate School, Yonsei University, Department of Physical Therapy, Kinetic Ergocise Based on Movement Analysis Laboratory, Yonsei University)
• Oh-yun Kwon(Department of Physical Therapy, Kinetic Ergocise Based on Movement Analysis Laboratory, Yonsei University, Department of Physical Therapy, College of Software and Digital Healthcare Convergence, Yonsei University, Wonju, Korea) Corresponding author