World Journal of Sport Sciences 7 (3): 149-153, 2012 ISSN 2078-4724 © IDOSI Publications, 2012 DOI: 10.5829/idosi.wjss.2012.7.3.71130 Corresponding Author: Elham Mohammadi, Department of Sport Medicine and Health, University of Tehran, Tehran, Iran. Tel: +09127769181. 149 Comparison of the Torso Stabilizer Muscles Endurance in Female Athletes with and Without Patellofemoral Pain Syndrome Elham Mohammadi, Reza Rajabi and Mohammad Hossein Alizadeh Department of Sport Medicine and Health, University of Tehran, Tehran, Iran Abstract: The purpose of this study was to compare the torso stabilizer muscles endurance in female athletes with and without patellofemoral pain syndrome. Diminished hip strength has been implicated as being contributory to lower-extremity misalignment and patellofemoral pain but other proximal muscle groups including the torso stabilizer muscles has not been investigated. Thirty female athletes diagnosed with patellofemoral pain syndrome (mean age; 21.60±2.75, mean weight; 60.70±8.70 and mean height; 165±.073) and 30 asymptomatic females athletes (mean age; 20.77±2.63, mean weight; 60.53±6.66 and mean height 164±.063) with history of 3 years participating in volleyball, basketball or handball for all subject, participated in this study. The protocol established by McGill was used to determine muscle endurance of the torso stabilizer muscles. The protocol consists of four tests that measure all aspects of the torso via isometric muscle endurance: trunk flexor test, trunk extensor test (Beiring Sorensen test) and left and right lateral musculature test (Side bridge test). Data were analyzed using the independent samples t-test in SPSS program and with the significance level set at P<0.05.The results showed a statistically significant difference between the two groups for torso stabilizer muscles endurance (P=.001) and the greatest differences were found in anterior part of the torso muscle endurance (abdominal muscles). The results indicate that young women with patellofemoral pain are less likely to demonstrate endurance in torso stabilizer muscles than age-matched control group women who are not symptomatic. In conclusion, based on this study results, it’s proposed that the torso stabilizer muscles endurance training would be used for prevention and treatment of Patellofemoral pain syndrome in persons with similar characteristics of this study samples. Key words: Patellofemoral Pain Syndrome %Female Athletes %Torso Stability %Endurance Muscles INTRODUCTION Core stability is the product of motor control and Patellofemoral pain syndrome is anterior knee pain; proposing that the stability of the pelvis and trunk is the pain is generated by retinaculum, subchondral bone, necessary for all movements of the extremities. The synovium, or local small nerve endings and muscle [1]. influence of foot mechanics on proximal structures has Several factors include overuse and overload of the been studied extensively. However, the influence of patellofemoral joint, biomechanical problems, muscular proximal stability on lower extremity structure and dysfunction and acute injury contribute to patellofemoral pathology remains largely unknown. There is a clear pain. Patellofemoral pain syndrome (PFPS) is most relationship between trunk muscle activity and lower common in athletes with reported incidence rates greater extremity movement. Current evidence suggests that than 25 % [2]. It has also been reported that females, as decreased core stability may predispose to injury and that compared with their male counterparts, are significantly appropriate training may reduce injury. Researchers more likely to experience PFPS Females are at greater risk identified trunk muscle activity before the activity of the of developing PFPS because of anatomical differences lower extremities, which served to stiffen the spine to that result in higher Q angles as compared to males [3]. provide a foundation for functional movements [1, 2]. muscular capacity of the lumbo-pelvic-hip complex [4]