Supervisors: Mohammed Shawki Abdelsalam, Ahmad Hamdi Azzam, Mohammed Moustafa Aldosouki Hegazy.

Thesis (Ph.D.)-Cairo university, Faculty of Physical Therapy, 2023.

Includes bibliographical references.

Background: Knee osteoarthritis is a common musculoskeletal disorder associated with pain, functional disability, impaired proprioception, and reduced quadriceps muscle strength. Lumbar core strengthening exercises may provide additional benefits by improving trunk stability and neuromuscular control, which may positively influence lower-limb function.

Objective: This study aimed to investigate the effect of lumbar core strengthening exercises on pain, disability, proprioception, and quadriceps muscle strength in patients with knee osteoarthritis.

Methods: Eighty patients with knee osteoarthritis were recruited and assigned to two groups. The control group received conventional physical therapy, while the experimental group received conventional physical therapy in addition to a lumbar core strengthening exercise program. Pain, disability, knee proprioception, and quadriceps muscle strength were assessed before and after the intervention.

Results: The findings demonstrated significant improvements in pain, disability, proprioception, and quadriceps muscle strength following the intervention. The group receiving lumbar core strengthening exercises in addition to conventional physical therapy showed greater improvements in the assessed outcomes compared with conventional physical therapy alone.

Conclusion: Lumbar core strengthening exercises, when added to conventional physical therapy, may be an effective approach for improving pain, functional disability, proprioception, and quadriceps muscle strength in patients with knee osteoarthritis. Incorporating core strengthening into rehabilitation programs may enhance functional recovery and improve clinical outcomes in this population