Static Foot Pressure and Percentage Contact Area of the Foot as an Assessment Tool for the Success of Anterior Cruciate Ligament Reconstruction: A Cross-sectional Study

Abstract

Introduction: Anterior Cruciate Ligament (ACL) plays a vital role in gait balancing and lower limb kinematics. Any injury to the ACL leads to gait imbalance and alterations in foot pressure distribution. The stability and biomechanics of the lower limb after ACL Reconstruction (ACLR) can be measured through foot pressure analysis, gait analysis, and percentage contact area of the foot, among others. Aim: To evaluate the static foot pressure and percentage contact area of the foot in ACL deficient group, comparing it with the ACLR group and the normal healthy individual group. Materials and Methods: An analytical cross-sectional study was conducted at the Department of Sports Medicine, King George Medical University, Lucknow, Uttar Pradesh, India from March 10, 2021 to March 15, 2023. A total of 15 patients in each group (ACL injury, ACLR patients, and normal healthy individuals) were included in this study. Foot pressures (static) were recorded in all three groups using the BTS P-WALK system with BTS Biomedical software, which included high- density sensors and a plate size of 700 × 500 × 5 mm. Statistical analysis was performed using Statistical Package for the Social Sciences (SPSS) software version 26.0. Chi-square and linear regression tests were used to analyse the differences between the groups. Results: In the intragroup analysis, ACL deficient patients’ ipsilateral limbs showed lower foot pressure in the mid-foot (7±3.4), hind-foot (40.33±10.08), and whole foot pressure (110.19±34.7 Pascal (N/M2)) (p-value>0.05) compared to normal healthy individuals (126.06±19.4 Pascal (N/M2) (p>0.05) and ACLR (125.06±14.3 Pascal (N/M2)) (p-value>0.05) groups, which suggested insignificant differences. The percentage contact area of the foot was significantly lower (43.15±3.4) (p-value<0.001) compared to normal healthy individuals (49.82±0.84) and ACLR (49.02±0.91) groups. However, in intergroup comparisons, the differences in mid-foot, whole foot pressure, and percentage contact area of the foot were significant (p-value <0.001) within the groups. Conclusion: Although there is a wide range of variation in the values of static foot pressure and percentage contact area of the foot in ACL deficient patients, after ACLR, these values become nearly similar to those of normal healthy individuals at around one year after ACLR.