en حرکت‌شناسی و آسيب‌های ورزشی Kinesiology and Sport Injuries مقاله اصیل Original Article <div style="text-align: justify;"><strong>Background. </strong>Patellofemoral osteoarthritis (PF OA) is a leading cause of significant pain and disability of the knee joint. Stair climbing dysfunction is commonly reported in this cohort. <strong>Objectives. </strong>To compare the temporal muscle activation between females with PF OA and healthy controls during stair ascent and decide whether there is a link between altered core activity and Patellofemoral osteoarthritis. <strong>Methods. </strong>A comparative observational study was conducted on 31 females with PF OA and 11 healthy ones. The electromyographic onset times of vasti, gluteus medius (GM), multifidus, and transversus abdominus (TrA) muscles were measured during the initiation of the stair ascending task. <strong>Results. </strong>A non-significant difference was detected between females with PF OA and controls regarding the onset times of all tested muscles except for the multifidus muscle, which significantly delayed activation in the PF OA group. <strong>Conclusion. </strong>Females with patellofemoral osteoarthritis showed a significantly delayed multifidus activation during ascending stairs which indicated the neuromotor dysfunction of core muscles compared to healthy controls. Core stability may be of clinical significance in managing patients with patellofemoral osteoarthritis. Prospective longitudinal studies are recommended for prioritizing the dysfunction.</div> Patellofemoral Osteoarthritis, Stair Ascent, Electromyography, Temporal Activation 0 0 http://aassjournal.com/browse.php?a_code=A-11-1606-1&slc_lang=en&sid=1 Jilan Adel Jilanadel88@gmail.com 100319475328460010761 100319475328460010761 No Department of Physical Therapy for Musculoskeletal Disorders and Its Surgery, Faculty of Physical Therapy, Kafrelsheikh University, Kafr Elsheikh, Egypt Alaa Eldin Balbaa balbaaa@hotmail.com 100319475328460010762 100319475328460010762 No 2Department of Physical Therapy for Musculoskeletal Disorders and Its Surgery, Faculty of Physical Therapy, Cairo University, Cairo, Egypt. Faculty of Physical Therapy, Nahda University, Beni Sueif, Egypt Hala R. ElHabashy hala.elhabashy@hotmail.com 100319475328460010763 100319475328460010763 No Clinical Neurophysiology Unit, Kasr Alainy Medical School, Cairo University, Cairo, Egypt Mai R. Ibraheem Mai_amer@fci.kfs.edu.eg 100319475328460010764 100319475328460010764 No Department of Information Technology, Faculty of Computers and information, Kafrelsheikh University, Kafrelsheikh, Egypt Nadia Fayaz Nadiafayaz2000@gmail.com 100319475328460010765 100319475328460010765 No Department of Physical Therapy for Musculoskeletal Disorders and Its Surgery, Faculty of Physical Therapy, Cairo University, Cairo, Egypt Samar Abbass samar.ahmed.mahmoud@gmail.com 100319475328460010766 100319475328460010766 No Department of Biomedical Engineering and Systems, Faculty of Engineering, Cairo University, Cairo, Egypt Amany ElZawahry amany.elzawahry@gmail.com 100319475328460010767 100319475328460010767 No Department of Biomedical Engineering and Systems, Faculty of Engineering, Cairo University, Cairo, Egypt Hamda Ahmad Hamda Hamada.ahmed@pt.cu.edu.eg 100319475328460010768 100319475328460010768 Yes Department of Biomechanics, Faculty of Physical Therapy, Cairo University, Cairo, Egypt Amina Awad amina_awad@cu.edu.eg 100319475328460010769 100319475328460010769 No Department of Physical Therapy for Neuromuscular Disorders and its surgery, Faculty of Physical Therapy, Cairo University, Cairo, Egypt