en بيومکانيک ورزشی و شاخه‌های وابسته بدان Sport Biomechanics and its related branches مقاله اصیل Original Article <div style="text-align: justify;"><span style="font-family:times new roman;"><span style="font-size:12px;"><strong>Background. </strong>The kinematics of a controlled functional task in female volleyball athletes may be an interesting area of study. Therefore, investigating if there are kinematic changes in a jump landing jump task among female athletes with low back pain (LBP) may help therapists and trainers better prevent and/or rehabilitate LBP in athletes.<br> <strong>Objectives. </strong>The purpose of this study was to examine lumbopelvic and lower extremity kinematics in athletes with persistent LBP during a jumping task.<br> <strong>Methods. </strong>A comparative </span></span><span style="font-family:times new roman;"><span style="font-size:12px;">cross sectional</span></span><span style="font-family:times new roman;"><span style="font-size:12px;"> study conducted in a university research laboratory. Professional female volleyball players with (n = 20) and without (n = 18) LBP were recruited from the Iranian female volleyball league. To reduce heterogeneity, one particular subgroup of athletes with LBP were selected. Kinematic data including lumbar extension, hip flexion, rotation and adduction and knee flexion and abduction angles when the center of mass was at minimum height during a jump-landing-jump maneuver were collected using a Vicon motion analysis system and analysed using MATLAB software. Independent t-tests were used to compare mean values between the groups.<br> <strong>Results.</strong> Athletes with LBP had significantly greater hip flexion (LBP: -73.62&plusmn;11.06˚; Control: -62.88&plusmn;7.03˚, p=0.016) and significantly less knee flexion (LBP: 77.06&plusmn;7.27 ˚, Control: 81.62&plusmn;4.70 ˚, p=0.029) at the lowest point of the jump than athletes without LBP. There were no other significant differences between the groups (p>0.05).<br> <strong>Conclusion. </strong>A subgroup of female athletes with LBP display altered lower extremity kinematics during a jump task than athletes without LBP. This may have important implications for lower limb performance and injury.</span></span></div> Biomechanics, Low Back Pain, Knee, Hip 23 30 http://aassjournal.com/browse.php?a_code=A-11-599-2&slc_lang=en&sid=1 Rahman Sheikhhoseini rahman.pt82@gmail.com 10031947532846007083 10031947532846007083 Yes Faculty of Sport Sciences, Allameh Tabataba'i University, Tehran, Iran Mohammad-Hossein Alizadeh mhalizadeh47@yahoo.com 10031947532846007084 10031947532846007084 No Health & Sport Medicine Department, University of Tehran, Tehran, Iran Mahyar Salavati mahyarsalavati@gmail.com 10031947532846007085 10031947532846007085 No Department of Physical Therapy, University of Social Welfare and Rehabilitation, Tehran, Iran Kieran O'Sullivan kieran.osullivan@aspetar.com 10031947532846007086 10031947532846007086 No Sports Spine Centre, Aspetar Orthopaedic and Sports Hospital, Doha, Qatar. Department of Clinical Therapies, Univerisyt of Limerick, Limerick, Ireland Elham Shirzad eshirzad@ut.ac.ir 10031947532846007087 10031947532846007087 No Health & Sport Medicine Department, University of Tehran, Tehran, Iran Marzieh Movahed mrz.movahed@gmail.com 10031947532846007088 10031947532846007088 No Department of Physiotherapy, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran