The effects of a central body stability training program on postural control, dynamic and static balance of volleyball players

Dissertation for M.A

in the field of physical education

Abstract:

The purpose of this study was to investigate the effects of a central body stability training program on posture control, dynamic balance and stability of volleyball players. The statistical population of this research was male volunteer volleyball players aged 18 to 24 from Zanjan city, who were divided into two groups of 15 experimental and control groups by simple random method. The training program included five semi-sit-ups, sit-ups with rotation, bridge from the side, bridge in the palm position and four stages of strengthening exercises for the lower abdomen. After collecting the pre-test data, the subjects of the experimental group performed central stabilizer muscle training for six weeks. Y test, star test and Sharpand-Romberg balance test with open eyes were used to measure posture control, dynamic balance and static balance, respectively. Correlated and independent t-tests were used to study the significance of intra-group and inter-group in the pre-test and post-test, respectively. The significance level of the tests was considered at the level of p?0.05. The research results showed that there is a significant increase in the averages of the reaching distance in the Y balance test for all directions. Also, the results showed a significant increase in the values ??of static and dynamic balance after central stability exercises in the experimental group compared to the control group, and therefore it can be concluded that central stability exercises can be used to increase the balance of volleyball players.

Key words: posture control, static balance, dynamic balance, central stability exercises and volleyball players.

1-1. Introduction:

Volleyball is a developing sport that has attracted many fans around the world and is one of the most widespread sports that is played by more than millions of people around the world. This sport is very popular in different countries and especially in our country, so much so that by making it to the World League matches and presenting beautiful and heartwarming games and defeating powerful teams like Italy, Cuba and Germany, a wave of great happiness and joy swept over our beloved country. The increase in the number of athletes and sports enthusiasts has also increased the amount of sports-related injuries (74). Injury is an inevitable part of any sport. It is effective (27). The neuromuscular center directs the position and condition of the upper and lower third of the cylinder, and according to King's classification, the upper and lower parts of the cylinder are very effective in the overall performance of volleyball skills. King also stated that a change in the mechanics of the system would likely lead to a change in the pattern of neuromuscular recruitment. Therefore, the performance of the upper and lower limbs can be greatly affected by the mechanical and neuromuscular stability of the central body region (28). Therefore, the main goal of stability exercises is to preserve the joint structures of the spine from small and frequent injuries, the return of pain and destructive changes, and to create the physical capacity to maintain the normal state of the spine during daily activities, which is done by increasing the endurance and coordination of the stabilizing muscles of the spine. Also, this area helps to perform sports as an interface by effectively transferring the forces produced in the lower limb to the upper limb through the trunk (29).

1-2.  Problem statement:

Stability of the core region of the body provides numerous benefits for the musculoskeletal system, from maintaining back health to preventing knee ligament damage. As a research, maintaining the stability of the central region of the body is always the main interest and trend of sports medicine doctors, physiotherapists and musculoskeletal researchers (28). The stability of the central region of the body is the ability of the lumbar, pelvic, and thigh structures to prevent bending due to pressure and to return to the equilibrium position after collapsing, which we see after performing each spike in volleyball. Although the static elements (bones and soft tissue) help to some extent, the stability of the central region of the body is mainly maintained by the dynamic function of the muscle elements (29). There is a clear relationship between trunk muscle activity and lower body movement.Current evidence suggests that reduced stability of the core can set the stage for injury and that proper training can reduce injury. Due to the simultaneous movement of the vertebral column in three dimensions, many loads act on the inactive bony structures of the vertebral column ligaments; Therefore, the spine is prone to injury. As a result, it is necessary to control the movement by the lumbar and abdominal muscles by creating the optimal required stiffness against the loads on the lumbar spine and to prevent damage by overload. Also, the main goal of spine stabilization exercises is to create physical capacity to maintain the normal position of the spine during daily activities; which does this by increasing the tolerance and coordination of the spinal stabilizing muscles (17). Due to the possibility of causing various injuries due to the lack of balance and ability to control the posture of volleyball players, stability exercises support damaged and healthy tissues to speed up their repair and strengthening, while preventing accumulated loads that can cause weak structures.

The stability of the central body area can be evaluated by isometric, isokinetic and isoinertial methods. Appropriate intervention is likely to reduce the rate of trunk and lower limb injuries. A growing body of research literature indicates that core stability is an important component of any large motor activity (15). Authors from various experts in the etiology and treatment of musculoskeletal injuries, which range from central points such as spine, thigh, pelvis to peripheral points such as shoulder, knee and ankle, understood these factors implicitly. Most evidence supports the integrity of the relationship between core stability and musculoskeletal injury. Neuromuscular exercises, which include balance and receiving information about postural movements of the body by the sensory system, are among the most effective exercises for strengthening dynamic and static balance (28). Balance is one of the integral and key components of almost all daily activities for athletes' performances. Gambetta and Ger stated that balance is the most important part of an athlete's ability and is involved in almost any form of activity. Balance is a complex motor skill that describes the dynamics of body posture to prevent falls. Therefore, in terms of the importance of dynamic balance in the optimal implementation of special skills in volleyball and prevention of lower limb injuries, the researcher sought to investigate the effect of stability exercises in the central body region on changes in dynamic balance, static balance and posture control of amateur volleyball players in Zanjan city, so that in this way he can take effective steps in the direction of preventing sports injuries (33). Various researchers have investigated the effect of central stability exercises on balance. In this context, Nicol (2009) examined the effect of 6 weeks of central stability training in healthy people. In this research, the experimental group participated in a supervised strengthening central stability training program for 6 weeks and 3 sessions per week, which had regular gradual progress, and the control group was prohibited from any central stability training. After 6 weeks of exercises, the research results showed an increase in balance in these people, which was associated with an improvement in joint proprioception (7). Also, Karps (2007) in a research conducted to investigate the effects of a back strength and stability program on balance and hip kinematics while walking in women, found that stability and strength training during 20 sessions and for 7 weeks can reduce back pain and improve the strength of the pelvic girdle in women. According to the research done, the researcher seeks to answer the question whether 6 weeks of core stabilization training has an effect on the static, dynamic balance and posture control of volleyball players or not? Thirty male volleyball players were enrolled in this study. The samples consisted of subjects were divided into two groups. Including a group of Core Stabilization-Training Program and Control Group. Core stabilization training was performed for six weeks for the study groups. Y balance test (YBT), Sebt test and Sharpened-Romberg test were used for evaluation of the subjects' postural control, dynamic and static balance. To analyze the data, Sample T. Test tests were used (P?0.05).