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http://dx.doi.org/10.14400/JDC.2019.17.3.463

The Effect of Knee Muscle Imbalance on Motion of Back Squat  

Sohn, Jee-Hoon (Department of Physical Education, Jeonju University)
Publication Information
Journal of Digital Convergence / v.17, no.3, 2019 , pp. 463-471 More about this Journal
Abstract
The purpose of this study was to investigate the effect of muscle imbalance on motion of back squat. The isokinetic muscle strength of the 8 subjects was recorded for the knee flexion/extension by the cybex 770 dynamometer. Each subject performed 3 back squats with the long barbell with an intensity of 25% body weight(BW), 50%BW, 100%BW, 125%BW. During the back squat through the recorded kinematic data the subjects' maximum flexion and extension knee angle, center of mass displacement and V-COP were calculated for evaluation of the stability of the movement. For the statistical analysis independent t-test was used. Knee flexion angle and COM displacement are dominated by the reciprocal muscle ratio. V-COP factor was dominated by bilateral extension deficit. Based on the results we can know that as the intensity of the squat increased to a level control was difficult because the muscles' imbalance influenced the movement.
Keywords
Muscle strength imbalance; Reciprocal muscle strength ratio; Deficit; Back squat; Loads;
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1 H. Y. Jung. (2009). Influence that Isokinetic exercise program for 8 weeks affects isokinetic muscle function, bone mineral density, and balance ability of low back pain patient. Master Dissertation. Sungshin Women's university, Seoul.
2 D. H. Perrin, R. Robertson & R. Ray. (1987). Bilateral isokinetic peak torque, torque acceleration energy, power, and work relationships in athletes and nonathletes. Journal of Orthopaedic and Sports Physical Therapy, 9(5), 184-189.   DOI
3 O. Alizadehkhaiyat, A. Fisher, G. Kemp & S. Frostick. (2007). Strength and fatigability of selected muscles in upper limb: assessing muscle imbalance relevant to tennis elbow. Journal of Electromyography and Kinesiology, 17(4), 428-436.   DOI
4 Y. J. Kim, K. C. Eh & S. D. Jang. (2001). The effect of squat exercise on cardio-respiratory and stress hormone. Journal of Sport and Leisure Studies, 16, 297-305.
5 R. F. Escamilla. (2001). Knee biomechanics of the dynamic squat exercise. Medicine and Science in Sports and Exercise, 33(1), 127-141.   DOI
6 K. J. Choi, B. H, Kim, J. R. Yoon & D. D. Bang. (2005). Analyzing skill-characteristics on foreign wrestling competitors and developing competition strategy for preparing 2004 olympic games. Korean Journal of Sport Science, 16(4), 60-70.
7 D. Wathen. (1994). Muscle balance. In: Essentials of strength training and conditioning. Champaign, IL: Human Kinetics.
8 P. Aagaard, E. B. Simonsen, S. P. Magnusson, B. Larsson & P. Dyhre-Poulsen. (1998). A new concept for isokinetic hamstring: quadriceps muscle strength ratio. The American Journal of Sports Medicine, 26(2), 231-237.   DOI
9 V. Baltzopoulos & D. Brodie. (1989). Isokinetic dynamometry. Applications and limitations. Sports medicine, 8(2), 101-116.   DOI
10 K. M. Newell & D. M. Corcos. (1993). Variability and Motor Control. Champaign, IL: Human Kinetics.
11 D. W. Lee. (2005). A review on the mechanism of human postural control. Korean Journal of Sport Biomechanics, 15(1), 45-61.   DOI
12 W. J. Evans. (1999). What is sarcopenia? The Journals of Gerontology Series A: Biological Sciences and Medical Sciences, 50(5), 5-8.
13 S. J. Fleck & J. Falkel. (1986). Value of resistance training for the reduction of sports injuries. Sports Medicine, 3(1), 61-68.   DOI
14 I. K. Jung & S. Y. Kim. (2004). A Comparative Study of Upper Body's Muscle Power Ratio between Judo Players and Gymnastic Players. Korea Sport Research, 15(2), 1383-1390.
15 A. Cools, E. Witvrouw, G. Declercq, G. Vanderstraeten & D. Cambier. (2004). Evaluation of isokinetic force production and associated muscle activity in the scapular rotators during a protraction-retraction movement in overhead athletes with impingement symptoms. British Journal of Sports Medicine, 38(1), 64-68.   DOI
16 T. Thomas, C. Zebas, M. Bahrke, J. Araujo & G. Etheridge. (1983). Physiological and psychological correlates of success in track and field athletes. British Journal of Sports Medicine, 17(2), 102-109.   DOI
17 J. Insall. (1982). Current concepts review: patellar pain. The Journal of Bone and Joint Surgery, 64, 147-151.   DOI
18 J. Kelso, E. L. Saltzman & B. Tuller. (1986). The dynamical perspective on speech production: Data and theory. Journal of Phonetics, 29-59.
19 S. J. Bowerman, D. R. Smith, M. Carlson & G. A. King. Requiao. (2006). A comparison of factors influencing ACL injury in male and female athletes and non-athletes. Physical Therapy in Sport, 7(3), 144-152.   DOI
20 P. J. Rasch & R. K. Burke. (1978). Kinesiology and applied anatomy(6th ed.). Philadelphia : Lea & Febiger.
21 K. M. Seo. (2005). Characteristic analysis of isokinetic muscle performance in swimmers. Master Dissertation. Kyonggi University, Suwon.
22 J. J. Kim, J. Y. Park & I. T. Ko. (2000). A study on isokinetic muscular strength of knee joint-concentric contraction and eccentric contraction. The Journal of Physical Education, 28, 345-358.
23 J. T. Kim, S. H. Kim, H. S. Kang & S. W. Youn. (1998). A study on the isokinetic functional strength of the trunk for the old male adults. Koran Journal of Sports Science, 7(1), 279-290.
24 S. J. Park & K. W. Lee. (1997). The effect of strengthening of isokinetic training for back pain relief. Institute of Martial Arts, 8(1), 139-147.
25 J. S. Harm. (2001). The comparison between muscular strength and endurance of thigh classified by dancing type. Master Dissertation. Cheongju University, Cheongju.
26 K. K. Kang & W. S. Chang. (2008). Peak torque moment and hamstring/quadriceps ratio of knee joint of taekwondo practitioners. The Korean Journal of Physical Education, 47(3), 461-471.
27 J. M. Lee. (2009). The effect of isokinetic training on flexor function development of a lumbago patient. The Korea Journal of Sports Science, 18(2), 1027-1036.