KEA vs Towel for Early Quad Activation Post Anterior Cruciate Ligament Reconstruction

The goal of this clinical trial is to learn if a novel Knee Extensors Activation (KEA) device can improve quadriceps muscle activation in adults after anterior cruciate ligament (ACL) reconstruction surgery. The study focuses on adults aged 18-45 years undergoing primary unilateral ACL reconstruction, a population commonly affected by this injury. The main questions it aims to answer are: Does using the KEA device lead to greater quadriceps muscle activation (measured via EMG) by postoperative Day 5 compared to standard care using a rolled towel? Does the KEA device improve early knee function, reduce pain, and decrease fear of movement compared to the towel method? Researchers will compare participants using the KEA device versus a control group using the conventional rolled towel during early postoperative rehabilitation to see if the KEA device provides better outcomes. Participants will: Begin quadriceps strengthening exercises on the first day after ACL surgery. Be randomly assigned to use either the KEA device or a rolled towel for isometric quadriceps exercises. Perform 3 sets of 10 repetitions of knee extension exercises, twice daily for 5 consecutive days. Undergo assessment of quadriceps EMG activation and complete questionnaires (KOOS, IKDC, TSK, and VAS) on Day 5.