Pelvic Gait Symmetry and Morphometric Monitoring in ACL Rehabilitation: Integration of Wearable Sensors and Clinical Measurement Tools

Anterior cruciate ligament (ACL) injuries often cause persistent pelvic gait asymmetries, posing challenges for rehabilitation and functional recovery. This study applied an integrated monitoring approach combining wearable inertial measurement unit (IMU) sensors with established clinical tools in 32 individuals (9 women, 23 men; aged 19–64) following ACL reconstruction with patellar tendon autografts. Pelvic-mounted IMUs captured oscillations in the sagittal, transverse, and frontal planes during standardized walking tests, providing objective digital biomarkers of gait recovery. Complementary clinical assessments included knee range of motion, thigh circumference to detect muscle hypotrophy, knee swelling, and pain using a visual analogue scale (VAS). Patients performed targeted proprioceptive exercises as part of individualized rehabilitation. Over the rehabilitation period, VAS scores decreased from 13.6 to 3, knee swelling reduced from 2.88 cm to 1.09 cm, knee extension deficit decreased from 9.38° to 2.03° (angle remaining to achieve full extension), and flexion increased from 61.56° to 98.75°, while thigh muscle hypotrophy persisted and slightly increased from 1.13 cm to 2.53 cm. Pelvic oscillations improved in all planes, from 36.2 to 49.2 in the sagittal plane, from 71.9 to 92.2 in the transverse plane, and from 73.4 to 90.9 in the frontal plane, reflecting progressive recovery of gait dynamics as patients transitioned from crutch-assisted to independent walking. The integration of wearable sensor data with clinical metrics and exercise-based interventions demonstrates the potential of technology-driven rehabilitation monitoring to guide individualized therapy and optimize functional outcomes following ACL reconstruction.