The study aimed to study of prevalence of neuromuscular dysfunctions especially TD among the athletic population of rocket, team and water sports. The results of the present study showed that there is no significant difference between the scores of the tuck jump test and TD among elite athletes in three different sports. It seems that due to the significant differences in the nature, movement pattern, and sport technique and the limitation in the statistical sample among three sports, it is likely that with the presence of professional and high-level athletes, because of the more dominant movement patterns, there will be a significant difference among them.
Although there was no significant difference in this study, by analyzing and comparing the results of tests in three different sports, we found that among 90 athletes in table tennis, cycling, and swimming, 30 athletes from each sport in total, 27 subjects (30%) had TD and 63 subjects (70%) did not have TD. The number of people with TD was 12 (40%) in table tennis, 6 (20%) in cycling, and 9 (30%) in swimming (breaststroke and butterfly stroke swimmers), respectively. Also, the number of people without TD was 18 (60%) in table tennis, 24 (80%) in cycling, and 21 (70%) in swimming, respectively. This means that the most and the least people with TD were table tennis and cycling, respectively.
The present study shows that TD exists in every sport and can also increase the risk of future ACL injury for athletes. Injury prevention training programs are constantly being standardizing. Identifying and modifying injury risk factor is another goal of sport and health professionals (14). The neuromuscular control dysfunctions as one of the risk factors for injury are screened and assessed by tuck jump. It also allows a coach or a trainer to assess the risks of athlete injury without the use of expensive equipment (15). The results of the present study are consistent with the statements of previous researches that have highlighted the importance of the body core stability in various sports activities, examples of which are given in all three sports. According to research, in general, injuries in athletes occur in long-term training (16). In all sports, there are risk factors for injury. Previous studies have shown that the rate of lower extremity injury was higher than the upper extremity, which is between 39–59% of the total injuries presented (lower extremity, upper extremity, and trunk injuries) (17).
Table tennis is a sport characterized by small balls, high speed, a strong rotation, and many variations (18). The trunk plays an important role in the kinetic chain of table tennis techniques, which is part of the generator and transmitter of force. The table tennis service involves a variety of muscles and describes the specific musculoskeletal demands and needs of the trunk as very important. The repetitive and unilateral nature of table tennis movements, which in most situations involves service and continuous forehand, leads to adaptations and musculoskeletal imbalances in the body which can lead to an injury. (19). According to the studies, the researchers also stated that there is a high percentage of pelvic (core) injuries (5.76%) due to the characteristics of sudden blocking movements in the game of table tennis. Strains and sprains are the most common types of injury in most sports, and also, the research shows that even due to the excessive hyperextension of the knee while the footwork of table tennis players (which is the most important element in table tennis) in short steps compared to long steps, the risk of an ACL injury may increase (17). However, probably due to the unilateral nature of table tennis and its effect on one side of the body muscles, and due to the core stability muscles, one-way muscle strengthening, neuromuscular and musculoskeletal balance, this field generally has the highest number of people with TD (40%).
Core stability is also the basis for power generation when cycling (20). Repetitive movements in cycling and sustained or long-term postures of the pelvis and legs require efficient movement patterns to prevent stress and increased pressure exerted on the musculoskeletal structures of the lower extremity (20). Aside from the role of the trunk and arm muscles when cycling, the upper body may be involved in stabilizing the body, especially when cycling on uneven surfaces such as paving or off-road roads (21). Sustained and repetitive postures or prolonged lumbar flexion are also associated with low back pain. Altered kinematics of the spine, or patterns of core stability muscle activation, appear to be associated with repetitive nature and prolonged activity, leading to an excessive back injury (20). Cyclists often suffer from trunk pain, which is often due to lumbar spine hyperflexion, which potentially puts increasing pressure on the intervertebral discs during excessive forward flexion (22). Therefore, upper body mobility and stability of cycling is also an important factor in preventing injury, because the common injuries of overuse occur in the neck and back regions in long-distance cycling (23). However, it is probably due to the bilateral activity of the hip joints during pedaling and creation of continuous flexion movement of the thigh and its effect on both skeletal muscles (psoas muscles), and its strengthening and constant oscillation in the trunk to both left and right to the same extent and strengthening the stabilizing muscles, especially the core stability muscles and the trunk isometrically, this field generally had the lowest number of people with TD (20%).
The power of core stability muscle groups (abdominal, back, and thigh muscles) is essential to maintain proper posture, balance, and alignment in the aquatic environment (24). If these elements become weak and disturbed, the resistance forces increase and lead to inefficient movements and deterioration of the technique in swimming. Increasing the strength of a swimmer's core stability improves his ability to maintain efficient technique throughout the competition (24). Strength, endurance, coordination, and extensive studies of core stability can be considered as key factors in the development of swimmers' motor skills (24). Lacking central stability or having a core deficit or TD can also be a risk factor for shoulder dysfunction in sports (especially in overhead movements such as swimming) (25). Also, swimmers with core stability weakness or TD tend to oscillate and sway their body instead of maintaining their posture, which leads to more wave tensions, which in turn prevents the swimmer from efficient propulsion (26). Musculoskeletal injuries in the swimmer population are usually due to cumulative and recurrent trauma. Careful monitoring of the volume, intensity, and duration of training by coaches and trainers can help reduce overuse injuries and identify high-risk swimmers (4). Core stability’s stamina and endurance are also essential components of any injury prevention program. Strengthening the core stability muscles should be emphasized in all exercise programs (4). The purpose is to increase the development of pelvic control by preventing anterior pelvic tilt and lumbar lordosis and reducing stress and strain on facet joints, especially in breaststroke and butterfly stroke swimmers (4). However, probably due to the activity of the trunk to control trunk movements and water resistance and its effect on trunk stabilizing muscles and neuromuscular adaptation, this sport has fewer people with TD than table tennis but has more people with TD than cycling (30%).
Although there was no significant difference in this study the value of research was not reduced. According to the present study, valuable information such as the percentage of people with and without TD in various sports, especially table tennis, cycling, and swimming (breaststroke and butterfly stroke swimmers), which have different movement patterns, was found to help future researchers who intend to have research in this field, and the basis for future research, especially to provide core stability exercise protocols.
Finally, It is worth mentioning that this research has been registered and approved by code: IR.GUMS.REC.1398.463 in the research ethics committee of Medical Science of University of Guilan, and also this article is extracted from the master thesis of sports injuries and corrective exercise of the corresponding author at the University of Guilan.