عنوان مقاله [English]
Background & Purpose: The location of center pressure and the amplitude of vertical ground reaction force (GRFz) during daily activities such as walking and step descent and ascent is associated with lower limb and lumbar injuries. The aim of this study was to examine the effects of two different resistance training programs on the biomechanical variables such as vertical ground reaction forces and center of pressure (COPx) during stair descent.
Methodology: Twenty healthy male students of Bu Ali Sina University were randomly divided into squat (average age: 25.1±2.7 year) and leg press (average age: 23.8±3.2 year) groups. GRFz and COPx values before and after 12 sessions of exercise recorded by force plate at sampling rate of 1000 Hz. The squat group performed squat movement with maximum hip adduction, while the leg press group performed leg press movement with maximum hip adduction during 12 sessions. Paired and independent sample t tests were used for within and between groups comparisons, respectively. The significant level was set at pResults: In leg press group, mediolateral displacements of COP after training program was decreased (P=0.027). However, GRF and COP values were not statistically different between both groups.
Conclusion: Leg press training could improve center of pressure (COP) displacement, and the second peak of GRFz, and consequently lead to improvement in postural control during step descent.
##de Oliveira Silva D, Barton CJ, Pazzinatto MF, Briani RV, de Azevedo FM. 2016. Proximal mechanics during stair ascent are more discriminate of females with patellofemoral pain than distal mechanics. Clinical Biomechanics. 35:56-61.##Cappozzo A, Marchetti M, Tosi V. Biolocomotion: a century of research using moving pictures: Promograph; 1992.##Lewis J, Freisinger G, Pan X, Siston R, Schmitt L, Chaudhari A. 2015. Changes in lower extremity peak angles, moments and muscle activations during stair climbing at different speeds. Journal of Electromyography and Kinesiology. 25(6):982-9.##Costigan PA, Deluzio KJ, Wyss UP. 2002. Knee and hip kinetics during normal stair climbing. Gait & posture. 16(1):31-7.##Qu X, Hu X. 2014. Lower-extremity kinematics and postural stability during stair negotiation: Effects of two cognitive tasks. Clinical Biomechanics. 29(1):40-6.##Lord SR, Ward JA, Williams P, Anstey KJ. 1993. An epidemiological study of falls in older community‐dwelling women: the Randwick falls and fractures study. Australian journal of public health. 17(3):240-5.## Startzell JK, Owens DA, Mulfinger LM, Cavanagh PR. 2000. Stair negotiation in older people: a review. Journal of the American Geriatrics Society. 48(5):567-80.##Trombini-Souza F, Kimura A, Ribeiro AP, Butugan M, Akashi P, Passaro AC, et al. 2011. Inexpensive footwear decreases joint loading in elderly women with knee osteoarthritis. Gait & posture. 34(1):126-30.##Nigg BM, Emery C, Hiemstra LA. 2006. Unstable shoe construction and reduction of pain in osteoarthritis patients. Medicine and Science in Sports and Exercise. 38(10):1701.##Grasso R, Bianchi L, Lacquaniti F. 1998. Motor patterns for human gait: backward versus forward locomotion. Journal of Neurophysiology. 80(4):1868-85.##Stacoff A, Diezi C, Luder G, Stüssi E, Kramers-de Quervain IA. 2005. Ground reaction forces on stairs: effects of stair inclination and age. Gait & posture. 21(1):24-38.##Spanjaard M, Reeves ND, Van Dieën J, Baltzopoulos V, Maganaris CN. 2009. Influence of gait velocity on gastrocnemius muscle fascicle behaviour during stair negotiation. Journal of Electromyography and Kinesiology. 19(2):304-13.##Spanjaard M, Reeves ND, Van Dieën J, Baltzopoulos V, Maganaris CN. 2008. Lower-limb biomechanics during stair descent: influence of step-height and body mass. Journal of experimental biology. 211(9):1368-75.##Reeves ND, Spanjaard M, Mohagheghi AA, Baltzopoulos V, Maganaris CN. 2008. The demands of stair descent relative to maximum capacities in elderly and young adults. Journal of Electromyography and Kinesiology. 18(2):218-27.##Reid SM, Lynn SK, Musselman RP, Costigan PA. 2007. Knee biomechanics of alternate stair ambulation patterns. Medicine and science in sports and exercise. 39(11):2005.##Riener R, Rabuffetti M, Frigo C. 2002. Stair ascent and descent at different inclinations. Gait & posture. 15(1):32-44.##Savvidis E, von der Decken C. 1999. Forces acting on foot soles during stair climbing in healthy probands and in patients with coxarthrosis. Biomedizinische Technik Biomedical engineering. 44(4):98-103.## Christina KA, Cavanagh PR. 2002. Ground reaction forces and frictional demands during stair descent: effects of age and illumination. Gait & posture. 15(2):153-8.##Lobo da Costa P, Amadio A editors. Ground reaction force factors and electromyographic patterns during level and stair walking in children. Proceedings of the, XV, congress of the international society of biomechanics; 1995.##Salsich GB, Brechter JH, Powers CM. 2001. Lower extremity kinetics during stair ambulation in patients with and without patellofemoral pain. Clinical Biomechanics. 16(10):906-12.##Kaufman KR, Hughes C, Morrey BF, Morrey M, An K-N. 2001. Gait characteristics of patients with knee osteoarthritis. Journal of biomechanics. 34(7):907-15.##Hanten WP, Schulthies SS. 1990. Exercise effect on electromyographic activity of the vastus medialis oblique and vastus lateralis muscles. Physical Therapy. 70(9):561-5.##Noorbhai H. 2012. The effects of open vs closed kinetic chain exercises among injured adolescent cricket players in KZN, South Africa. Journal of Science and Medicine in Sport. 15:S131.##Levin S, de Solórzano SL, Scarr G. 2017. The significance of closed kinematic chains to biological movement and dynamic stability. Journal of Bodywork and Movement Therapies. [In press]##Peng H-T, Kernozek TW, Song C-Y. 2013. Muscle activation of vastus medialis obliquus and vastus lateralis during a dynamic leg press exercise with and without isometric hip adduction. Physical Therapy in Sport. 14(1):44-9.##Earl J, Schmitz RJ, Arnold B. 2001. Activation of the VMO and VL during dynamic mini-squat exercises with and without isometric hip adduction. Journal of Electromyography and Kinesiology. 11(6):381-6.##Coqueiro KRR, Bevilaqua-Grossi D, Bérzin F, Soares AB, Candolo C, Monteiro-Pedro V. 2005. Analysis on the activation of the VMO and VLL muscles during semisquat exercises with and without hip adduction in individuals with patellofemoral pain syndrome. Journal of Electromyography and Kinesiology. 15(6):596-603.##Lymbery JK, Gilleard W. 2005. The stance phase of walking during late pregnancy: temporospatial and ground reaction force variables. Journal of the American Podiatric Medical Association. 95(3):247-53.##McCrory JL, Chambers AJ, Daftary A, Redfern MS. 2011. Ground reaction forces during gait in pregnant fallers and non-fallers. Gait & posture. 34(4):524-8.##Hamel KA, Okita N, Bus SA, Cavanagh PR. 2005. A comparison of foot/ground interaction during stair negotiation and level walking in young and older women. Ergonomics. 48(8):1047-56.##Cohen J. Statistical power analysis for the behavior science. Lawrance Eribaum Association. 1988.##Laprade J, Culham E, Brouwer B. 1998. Comparison of five isometric exercises in the recruitment of the vastus medialis oblique in persons with and without patellofemoral pain syndrome. Journal of Orthopaedic & Sports Physical Therapy. 27(3):197-204.##Alcock L, Vanicek N. 2015. Biomechanical demands of the 2-step transitional gait cycles linking level gait and stair descent gait in older women. Journal of biomechanics. 48(16):4191-7.##Whitehead JMA, Esposito ER, Wilken JM. 2016. Stair ascent and descent biomechanical adaptations while using a custom ankle-foot orthosis. Journal of Biomechanics. [In press]## Liikavainio T, Isolehto J, Helminen HJ, Perttunen J, Lepola V, Kiviranta I, et al. 2007. Loading and gait symmetry during level and stair walking in asymptomatic subjects with knee osteoarthritis: importance of quadriceps femoris in reducing impact force during heel strike? The Knee. 14(3):231-8.##Winter DA. Biomechanics and motor control of human movement: John Wiley & Sons; 2009.##