##Hong Y, Cheung CK. 2003. Electromyographic response of back muscles during load carriage. Gait & Posture. 17(1): 28-33.##Babakhani F, Woodra M. 2011. The effect of backpack load on the posture of children and its relationship to trunk muscle activity during walking on a treadmill. International Symposium Science based Prevention, Berlin, Germany.##Tseng HY, Lio BS. 2011. Effects of Load Carrying Methods and Stair Slopes on Physiological Response and Postures during Stairs Ascending and Descending. Industrial Health. 49(4): 30-36.##Demura T, Demura S. 2010. Relationship among Gait Parameters while Walking with Varying Loads. J Physiol Anthropol. 29(1): 29-34.##Hong Y, Li JX, Fong DTP. 2008. Effect of prolonged walking with backpack load on trunk muscle activity and fatigue in children. J of Electromyography and Kinesiology. 18(6): 990-996.##Hoseini H. 2011. The effect of backpacks with load condition on EMG activity of rectos abdominous and erectero spinal muscles in primery school. Olympic Magazine. 3:56-59.##Nylund T, Mattila V, Salmi T, Pihlajamaki H, Makela J. 2011. A follow-up case series. BMC, Musculoskeletal Disorders on lung volumes in Chinese primary school children. Early Human Development. 7962:7986.##Ozgul B, Akalan NE, Kuchimov Sh, Uygur F, Temelli Y, Polat MG. 2012. Effects of unilateral backpack carriage on biomechanics of gait in adolescents: a kinematic analysis. Acta Orthop Traumatol Turc. 46(4): 269-274.##Hazel M, Clarkson MA. 2012. Musculoskeletal Assessment. Philadelphia: Lippincott Williams & Wilkins.16:18-34.##Lucas-Cuevas AG, Perez-Soriano P, Bush M. 2013. Effects of Different Backpack Loads in Acceleration Transmission during Recreational Distance Walking. J of Human Kinetics Volume. 24(2): 81-89.##Vera-Garcia FJ, Moreside MM, McGill MS. 2010. MVC techniques to normalize trunk muscle EMG in healthy women. J of Electromyography and Kinesiology. 20: 10-16.##Daneshmandi H, Hoseini H. 2009. National norm of backpack weight in Iranian students. Research in sport sciences. 8(4):13-34.##Shamsoddini AR, Hollisaz MT, Hafezi R. 2010. Backpack Weight and Musculoskeletal Symptoms in School Students. Iranian J Publ Health. 39(4): 120-125.##Kathleen MH. 1993. Life Span Motor Development .Tehran, Samt Publishers. 12: 88-387. ##Linder T, Schulze CH. 2012. The effect of the Weight of Equipment on Muscle Activity of the Lower Extremity in Soldiers. The Scientific World Journal Volume. 76 (5): 13-18.##Namazizadeh M. 2003. The cinematic effects of carrying backpack on gait and posture in adolescence. Harakat magazine. 16(8): 5-21.##All-Hazza HM. 2006. How much load do Saudi school boys carry on their shoulder posture in Indian school children. Indian J Physiotherapy and Occupational Therapy. 1(2): 4-13.##