Extended Abstract
1. Introduction
Wrestling plays an essential role in terms of championships and international medal winnings for the country. Furthermore, its historical and chivalrous background in Iranian culture is significant. Thus, further scientific and survey studies are required in this respect. Injuries are highly prevalent among Freestyle, Greco-Roman, and Chookheh style wrestlers. Besides, we lack comprehensive information on these injuries at the old ages; therefore, a comparative study of wrestlers aged >18 years of age seems necessary. Previous research mainly focused on wrestlers’ injuries in high schools, and less comparison was performed between these wrestling styles [7].
The negative adaptation of the skeletal system to the motor needs and skills of athletes, especially in professional and elite athletes, is an important and well-studied subject; it has recently attracted the attention of researchers [22].
In this regard, various studies have investigated athletes in different sports. Comparing athletes with non-athletes in domestic and international dimensions has yielded different results. One study reported the presence of kyphosis (58.3%) of cyclists and their significant relationship with individual positions on bicycles (the effect of performance type on anomalies) in professional and semi-professional athletes. Comparing athletes with at least 2 years of training experience with non-athlete individuals, in normal standing suggested no significant difference in lumbar lordosis [21]. Therefore, the present study aimed to compare upper extremity musculoskeletal disorders in freestyle and Greco-Roman and Chookheh style Wrestlers.
2. Participants and Methods
This descriptive-analytical study was performed on 15 freestyle, 15 Greco-Roman, and 15 Chookheh style wrestlers in North Khorasan Province, Iran, in 2019. Prior to the measurements, none of the subjects performed heavy workout and spent only 6 minutes on warm-up exercises; the first 3 minutes were specified to jugging and the last 3 minutes to some stretching. To evaluate the kyphosis and lordosis abnormalities, a flexible ruler (Pistoleh, Iran) was used. Seidi et al. reported the validity of the flexible ruler in lumbar lordosis measurement to be >92% [25].

For measuring lumbar lordosis, the lumbar vertebrae and the second sacral vertebrae were marked, and the marked points on the spine were transferred to the ruler. Based on this method and according to the corresponding formula, the lordosis angle was determined [26]. Forward head posture and forward shoulders were measured using a semi-facial imaging technique.

The obtained data were analyzed in SPSS using descriptive statistics for mean score measurements, one-way analysis of Variance (ANOVA), and Scheffe posthoc test at the significance level of P<0.05.
3. Results
According to tables 1 and 2, the forward head angle in Greco-Roman and Chookheh style wrestlers was lower than in freestyle wrestlers (P<0.001). Forward shoulder in Greco-Roman and freestyle wrestlers was significantly higher than that in Chookheh style wrestlers (P<0.001). Furthermore, the kyphosis angle in Greco-Roman and freestyle wrestlers was significantly higher than that in the Chookheh style wrestlers (P<0.001). In addition, the lumbar lordosis angle in Greco-Roman style wrestlers was greater than that in freestyle wrestlers; this angle in freestyle wrestlers was also greater than that in Chookheh style wrestlers (P<0.001).

4. Discussion
The present study aimed to compare upper-trunk musculoskeletal disorders in Freestyle, Greco-Roman, and Chookheh style wrestlers. The obtained results indicated that forward head condition was more common in Freestyle, Greco-Roman, and Chookheh style wrestlers. However, forward shoulder and kyphosis were less common in Chookheh style wrestlers, compared to Freestyle and Greco-Roman wrestlers. In addition, lumbar hyperlordosis was more prevalent in Greco-Roman style wrestlers than in Freestyle ones. Besides, the Freestyle wrestlers were more likely to have this condition than the Chookheh style wrestlers. In general, in all upper trunk musculoskeletal disorders, except for lumbar lordosis, Freestyle wrestlers had a higher percentage of malformations, compared to Greco-Roman and Chookheh style wrestlers.
In terms of forward head posture, the collected results were consistent with those of other researchers. Bagherian et al. compared the ping pong players’ spine disorder with non-athletes. They concluded that the forward head angle of the ping pong players was significantly greater than that of the non-athletes. The reason for this difference is the ping pong players’ guard (body posture) during the play [20].
5. Conclusion
In conclusion, the sport type can influence the disorders in the head, shoulder, and spine. Continued training of athletes studied at the professional level may be associated with the risk of musculoskeletal disorders. Inappropriate long-term posture and deviation from the ideal posture over time can affect the musculoskeletal system.
Ethical Considerations
Compliance with ethical guidelines
All participants signed an informed consent form after being informed of the study objectives and methods, and being assured of the confidentiality of their personal information. They were free to leave the study at any time in case of any problem or dissatisfaction.
Funding
This study received no financial support from any organization.


Authors' contributions
Conceptualization, investigation, resources, and Funding Acquisition: Ali Roshandel Hesari and Mohsen Tavakoli; Methodology, preparing initial draft, Editing and Review: Ali Roshandel Hesari; Validation, analysis, visualization, supervision and administration: Mohsen Tavakoli.
Conflicts of interest
The authors declared no conflict of interest.
Acknowledgements
The authors would like to thank the Wrestling Board Chairman of North Khorasan Province and all wrestlers participated in this study for their valuable cooperation.