Evaluating an Advanced System with Flexible Dielectric Insole and Inertial Sensors for Post-ACL Reconstruction Assessment

Objective This study aims to validate an integrated system combining capacitive pressure-sensing insoles with wearable inertial sensors to evaluate rehabilitation progress after ACL reconstruction. Methods A total of 60 participants were recruited. The study proceeded in three stages: initial evaluation of the pressure sensors' sensitivity, then durability, accuracy assessment, and kinematics, and finally the return-to-play evaluation for post-ACL reconstruction patients. The study analyzed various gait parameters, jump tests (single-leg jumps, triple hops, and crossover hops), and the Limb Symmetry Index (LSI) . Results The study found comparable cadence rates (63.68 ± 3.72 steps/min for the integrated system vs. 59.73 ± 3.18 steps/min for Vicon), walking speeds (61.38±2.72 m/min vs. 64.92 ± 2.13 m/min), and step lengths (113.63 ± 9.12 cm vs. 114.26 ± 8.35 cm), the stance phase (61.18 ± 1.89% vs. 62.15 ± 2.25%) and swing phase (33.14 ± 2.19% vs. 32.72 ± 1.92%) measurements, along with peak joint angles for the ankle (18.2 ± 2.9 degrees vs. 19.1 ± 2.3 degrees), knee (63.3 ± 4.1 degrees vs. 65.1 ± 4.4 degrees), and hip (21.1 ± 3.4 degrees vs. 22.5± 3.2 degrees). Results from jump tests and the Limb Symmetry Index (LSI) were also analyzed. Conclusion The integrated system offers a novel approach in evaluating lower extremity biomechanics post-ACL reconstruction, showing significant potential for improvement in sports medicine rehabilitation.