Design and Manufacture the Eccentric Smith Machine.

Document Type : Original research papers


1 Department of Sports Biomechanics, Centeral Tehran Branch, Islamic Azad University, Tehran, Iran. Iran.,

2 Department of Sports Biomechanics, Faculty of Physical Education and Sports Science, Islamic Azad University of Central Tehran Branch, Tehran, Iran.

3 Department of Sport Biomechanics, Faculty of Humanities, Islamic Azad University, Hamedan Branch, Hamedan, Iran.



The study focuses on the design and manufacture of an Eccentric Smith Machine, incorporating specialized mechanical components for enhanced athletic benefits, minimizing injuries, and promoting hypertrophy. The Eccentric Smith Machine comprises three main parts: A stable Smith machine adapted for electrical motor shocks, an electrical component with a panel and motor, and a transmission system using four pulleys and two cables. The mechanical design facilitates acute and smooth bar movement, ensuring safety and ease of use for athletes of varying heights and strengths. The Eccentric Smith Machine demonstrates resilience to electrical motor power, simplicity in usage, and safety advantages. Its adaptability makes it accessible to athletes with diverse physical characteristics, providing a tool for effective and safe resistance training. The designed device has the potential to enhance physical fitness, particularly muscle hypertrophy. It stands as a viable option for athletes, offering a reduced risk of injuries during workouts. The Eccentric Smith Machine presents itself as an alternative for those recovering from minor injuries, contributing to overall workout safety.


Main Subjects


    1. Haskell WL, Lee I-M, Pate RR, Powell KE, Blair SN, Franklin BA, et al. Physical activity and public health: updated recommendation for adults from the American College of Sports Medicine and the American Heart Association. Circulation. 2007;116(9):1081.
    2. Armstrong R, Baltzopoulos V, Langan-Evans C, Clark D, Jarvis J, Stewart C, O’Brien T. An investigation of movement dynamics and muscle activity during traditional and accentuated-eccentric squatting. Plos one. 2022;17(11):e0276096.
    3. Weyand PG, Sternlight DB, Bellizzi MJ, Wright S. Faster top running speeds are achieved with greater ground forces not more rapid leg movements. Journal of applied physiology. 2000.
    4. Barker LA, Harry JR, Mercer JA. Relationships between countermovement jump ground reaction forces and jump height, reactive strength index, and jump time. The journal of strength & conditioning research. 2018;32(1):248-54.
    5. Folland JP, Williams AG. Morphological and neurological contributions to increased strength. Sports medicine. 2007;37:145-68.
    6. Balshaw TG, Massey GJ, Maden-Wilkinson TM, Morales-Artacho AJ, McKeown A, Appleby CL, Folland JP. Changes in agonist neural drive, hypertrophy and pre-training strength all contribute to the individual strength gains after resistance training. European journal of applied physiology. 2017;117:631-40.
    7. Suchomel TJ, Wagle JP, Douglas J, Taber CB, Harden M, Haff GG, Stone MH. Implementing eccentric resistance training—Part 1: A brief review of existing methods. Journal of Functional Morphology and Kinesiology. 2019;4(2):38.
    8. Armstrong R, Baltzopoulos V, Langan-Evans C, Clark D, Jarvis J, Stewart C, O’Brien T. Determining concentric and eccentric force–velocity profiles during squatting. European journal of applied physiology. 2022;122(3):769-79.
    9. Duchateau J, Baudry S. Insights into the neural control of eccentric contractions. Journal of Applied Physiology. 2014;116(11):1418-25.
    10. Guilhem G, Cornu C, Guével A. Neuromuscular and muscle-tendon system adaptations to isotonic and isokinetic eccentric exercise. Annals of physical and rehabilitation medicine. 2010;53(5):319-41.
    11. Hortobágyi T, Katch FI. Eccentric and concentric torque-velocity relationships during arm flexion and extension: Influence of strength level. European journal of applied physiology and occupational physiology. 1990;60:395-401.
    12. Alcazar J, Csapo R, Ara I, Alegre LM. On the shape of the force-velocity relationship in skeletal muscles: The linear, the hyperbolic, and the double-hyperbolic. Frontiers in physiology. 2019;10:438208.
    13. Liederbach M, Hiebert R. The relationship between eccentric and concentric measures of ankle strength and functional equinus in classical dancers. Journal of Dance Medicine & Science. 1997;1(2):55-61.
    14. Melo RC, Takahashi AC, Quitério RJ, Salvini TF, Catai AM. Eccentric torque-producing capacity is influenced by muscle length in older healthy adults. The Journal of Strength & Conditioning Research. 2016;30(1):259-66.
    15. Pain MT, Forrester SE. Predicting maximum eccentric strength from surface EMG measurements. Journal of biomechanics. 2009;42(11):1598-603.
    16. Boling MC, Padua DA, Alexander Creighton R. Concentric and eccentric torque of the hip musculature in individuals with and without patellofemoral pain. Journal of athletic training. 2009;44(1):7-13.
    17. Brazier J, Maloney S, Bishop C, Read PJ, Turner AN. Lower extremity stiffness: considerations for testing, performance enhancement, and injury risk. The Journal of Strength & Conditioning Research. 2019;33(4):1156-66.
    18. Hyldahl RD, Hubal MJ. Lengthening our perspective: morphological, cellular, and molecular responses to eccentric exercise. Muscle & nerve. 2014;49(2):155-70.
    19. Fang Y, Siemionow V, Sahgal V, Xiong F, Yue GH. Greater movement-related cortical potential during human eccentric versus concentric muscle contractions. Journal of Neurophysiology. 2001;86(4):1764-72.
    20. Pakosz P, Konieczny M, Domaszewski P, Dybek T, Gnoiński M, Skorupska E. Comparison of concentric and eccentric resistance training in terms of changes in the muscle contractile properties. Journal of Electromyography and Kinesiology. 2023;73:102824.
    21. Duchateau J, Enoka RM. Neural control of lengthening contractions. Journal of Experimental Biology. 2016;219(2):197-204.
    22. Bollinger LM, Brantley JT, Carpenter RS, Haydon MA, Best S, Abel MG. Quadriceps electromyography during flywheel-based inertial training (FIT) and dynamic constant external resistance (DCER) squats at similar tempo. Sports Biomechanics. 2022:1-12.
    23. Ünlü G, Çevikol C, Melekoglu T. Comparison of the effects of eccentric, concentric, and eccentric-concentric isotonic resistance training at two velocities on strength and muscle hypertrophy. The Journal of Strength & Conditioning Research. 2020;34(2):337-44.
    24. Higbie EJ, Cureton KJ, Warren III GL, Prior BM. Effects of concentric and eccentric training on muscle strength, cross-sectional area, and neural activation. Journal of applied physiology. 1996;81(5):2173-81.
    25. Vikne H, Refsnes PE, Ekmark M, Medbø JI, Gundersen V, Gundersen K. Muscular performance after concentric and eccentric exercise in trained men. Medicine and science in sports and exercise. 2006;38(10):1770-81.
    26. Kay MC, Register-Mihalik JK, Gray AD, Djoko A, Dompier TP, Kerr ZY. The epidemiology of severe injuries sustained by National Collegiate Athletic Association student-athletes, 2009–2010 through 2014–2015. Journal of athletic training. 2017;52(2):117-28.
    27. Jonhagen S, Nemeth G, Eriksson E. Hamstring injuries in sprinters: the role of concentric and eccentric hamstring muscle strength and flexibility. The American journal of sports medicine. 1994;22(2):262-6.
    28. Patel DP, Redshaw JD, Breyer BN, Smith TG, Erickson BA, Majercik SD, et al. High-grade renal injuries are often isolated in sports-related trauma. Injury. 2015;46(7):1245-9.
    29. Knapik DM, Metcalf KB, Voos JE. Isolated tearing and avulsion of the distal biceps femoris tendon during sporting activities: a systematic review. Orthopaedic Journal of Sports Medicine. 2018;6(7):2325967118781828.
    30. Grindem H, Eitzen I, Engebretsen L, Snyder-Mackler L, Risberg MA. Nonsurgical or surgical treatment of ACL injuries: knee function, sports participation, and knee reinjury: the Delaware-Oslo ACL Cohort Study. JBJS. 2014;96(15):1233-41.
    31. Nielsen RØ, Malisoux L, Møller M, Theisen D, Parner ET. Shedding light on the etiology of sports injuries: a look behind the scenes of time-to-event analyses. Journal of orthopaedic & sports physical therapy. 2016;46(4):300-11.
    32. Davies MA, Lawrence T, Edwards A, Lecky F, McKay CD, Stokes KA, Williams S. Serious sports-related injury in England and Wales from 2012-2017: a study protocol. Injury epidemiology. 2020;7:1-10.
    33. Farahpour N, Jafarnezhadgero A, Allard P, Majlesi M. Muscle activity and kinetics of lower limbs during walking in pronated feet individuals with and without low back pain. Journal of Electromyography and Kinesiology. 2018;39, 35-41.‏
    34. Jafarnezhadgero A, Sorkhe E, & Meamarbashi A. Efficacy of motion control shoes for reducing the frequency response of ground reaction forces in fatigued runners. Journal of Advanced Sport Technology. 2019;3(1), 8-21.‏