BRIEF CONTENTS

1. A PRELECTION ON:Effects of Functional Fatigue on Position Sense of Elbow and Shoulder Joints in Elite Female Table Tennis Players with Upper Crossed Syndrome Presented By: Dr. M. SahebozamaniProfessor of Sports Rehabilitation, ShahidBahoonar University of Kerman 2nd International Conference and Expo on Novel Physiotherapies London, UKJune, 2016

2. BRIEF CONTENTS

3. Upper crossed syndrome is a kind of musculoskeletal involvement that affects upper back and neck muscles leading weakness of the muscles and to strengthen the others. • This muscle imbalance leads to abnormalities in the person's forward head and rounded shoulders. • Several investigations have expressed the overall prevalence of UCS in the range of 34% to 42% among table tennis players. • In this field of sport as other fields, in exercises and tournaments, the athletes take an especial physical form that may predispose the body to postural abnormalities and deviations for a long time. Introduction

4. The concept of proprioception was primarily introduced by Sherrington in 1906 as a feedback from the nerves to the central nervous system. • Proprioception is a kind of the sense of touching. Pacinian corpuscles, ruffini organs, muscle spindles and Golgi tendon organs are mechanoreceptors that transfer mechanical changes as neural impalses through myelinated neural fibers from dorsal spinal root to central nervous system. • This sense has important roles such as participating in the accurate movements by neuromuscular control as well as joint stability through creating muscle reflexes. • Thus, the presence of poor proprioception and the weakness of these two functions, the increased risk for injury are expected. The studies could show that most injuries caused by table tennis playing are observable in two zones of elbow and shoulder girdle. Introduction (Cont.)

5. Several studies have been conducted on the effects of fatigue on athletic performance, but it seems that most of the fatigues were not functional and also there was not a correlation between fatigue and specific sports skills. • Also, most studies have been performed on healthy individuals without abnormalities or with emphasis on functional fatigue. • Hence, the present study aimed to assess the effects of functional fatigue as a risk factor for injury on position sense at the elbow and the shoulder girdle joints in the elite female table tennis players with upper crossed syndrome and also to compare with healthy players. Problem Statement

6. Participants This semi-experimental study was performed on 24 elite female table tennis players participating in the students Olympiad in 2014. All participants provided written informed consent to take part in this study. The research was approved by the ethical committee of the Institute of Research Management and Monitoring, ShahidBahonar University of Kerman Research Committee. Materials and Methods

7. Procedure The study was conducted to evaluate upper crossed syndrome in eligible subjects by taking pictures with camera (SONY CyberShot WX350, Japan) from a distance of 3 meters with light clothing and standing from lateral view with a camera angle of 90 degrees. In this regard, the presence of upper crossed syndrome was diagnosed based on forward head angle or FHA (determined by measuring the angle between a line drawn from the tragus to the C7 spinous process and a vertical plumb line through C7) and rounded shoulders angle or RSA (by measuring the angle between a line drawn from the tip of the acromion process to the C7 spinous process and a vertical plumb line through C7) based on the FHA higher than 46 degrees and RSA higher than 52 degrees. Materials and Methods (Cont.)

8. Procedure For assessing position sense at the elbow, in the flexor taut condition, elbow flexors were contracted with the arm held at 45°. After maintaining flexion for 5 seconds, subjects were asked to relax the arm and kept in mind the point. Then, the patients were asked to return the arm to the original position and then back again at the same point. The difference between the target angle and reconstructured angle was calculated as the absolute error using the photography of hand side view with the camera angle of 90 degrees and a distance of 3 meters by AutoCAD software. Materials and Methods (Cont.)

9. Elbow Joint Position Sense • For assessing position sense at the elbow, in the flexor taut condition, elbow flexors were contracted with the arm held at 45°. After maintaining flexion for 5 seconds, subjects were asked to relax the arm and kept in mind the point. • Then, the patients were asked to return the arm to the original position and then back again at the same point. The difference between the target angle and reconstructured angle was calculated as the absolute error using the photography of hand side view with the camera angle of 90 degrees and a distance of 3 meters by AutoCAD software. Materials and Methods (Cont.)

10. Shoulder Joint Position Sense • For assessing position sense at the shoulder, after marking ulnar bone and olecranon processes, the patient was asked to position arm and elbow at 90 degrees when lying on the bed. After closing the eyes using blindfolded, the patient was asked to slowly rotated arm internally to 45 degrees. • Then, the position was maintained constant and then asked to keep in mind the point. Then, the subject was asked to return arm to the original position and then back again on the same point. The difference between the target angle and reconstructured angle was calculated as the absolute error using the photography with the camera angle of 90 degrees and a distance of 3 meters by AutoCAD software. Materials and Methods (Cont.)

11. Fatigue Protocol • Before fatigue protocol and in order to prevent injuries, the players asked to begin warm up for 10 minutes to general movements (stretching), following 10 minutes warming up with specific movements (move looped forehand). This protocol was primarily designed by Aune specifically for table tennis. • In this protocol, patients called to turn thrown ball with the utmost precision and speed to a circular target on the opposite side of the net with a forehand technique. The patients said to return the rockets back to the starting position before each hitting. After performing each hit, a thrown ball moving in the opposite direction, and again returned to the original position to hit the next shot. The players moved to the opposite side of the ball thrown and returned again to the initial place to take the next shot. All balls were thrown to them by the balls float in a fixed location. The protocol consisted of four 4-minute stages that the frequency of throwing balls increased at each stage in order to increase the load. To ensure the fatigue level, the Borg scale test was used. Every 2 minutes, the subjects were asked to express their true feelings about the activity. The level of this scale ranged from at least 6 (very comfortable) to a maximum of 20 (very heavy), respectively. After creating functional fatigue, all the tests were reassessed and the data was recorded as a post-test. Materials and Methods (Cont.)

12. Statistical Methods • To determine the normal distribution of data and homogeneity of variances Shapiro and Lyon tests were used. • The Mixed Repeated Measure ANOVA test was used to assess the change in position sense after compared to before fatigue protocol. If significancy of χ2 value in Mauchly’s Test (p ≤ 0.05), the multivariate test (Wilks's lambda) was used, otherwise, the tests of Within-Subjects Effects (Greenhouse-Geisser corrected values for any effects) was considered. • The effect size of each data was assessed by partial eta squeard and considered as small effect (η2= 0.01), medium effect (η2= 0.06), and large effect (η2= 0.14). P values of 0.05 or less were considered statistically significant. Materials and Methods (Cont.)

13. The Findings

14. The two examined groups of players were matched in baseline characteristics including mean age, body weight and height, mean body mass index, and history of sport. • However, those players with the abnormality of upper crossed syndrome had significantly higher mean FHA and RSA values. The repeated measure test showed that the group with upper crossed syndrome experienced higher increase in position sense at the elbow following fatigue protocol compared to healthy players (5.58 degrees versus 2.38 degrees, main effect of 0.67, p < 0.001). • Also, the results showed no significant difference in the mean of angle reconstruction error between the two groups with and without abnormality after fatigue protocol before that (9.58 to 6.75 in group with upper crossed syndrome and 9.00 to 6.58 in healthy group, main effect of 0.01, p = 0.53). The Findings (Cont.)

15. The exact mechanism that affects joint position sense is not clear yet, but several possible mechanisms that may have an impact on this condition. • Studies have shown that increased joint laxity after fatigue may be involved in changes in joint position sense. It has been shown that fatigue increases the laxity around the hip joint ligaments (Nawata et al. 1999) and consequently despite the increased joint laxity, joint position sense may be decreased (Rozzi et al. 1999). • The second mechanism is the possible environmental effects on fatigue receptors. The relative role of each joint and muscle receptors in joint position sense impairment after functional fatigue still remains controversial. Discussion

16. In general, several reports have shown that fatigue has a greater effect on muscle receptors than the joint receptors. • Thus, the losing sense may be due to losing the inputs of muscle receptors (Hiemstra et al. 2001). In 2006, Allen and colleagues studied the effect of fatigue on sense of elbow. In this study, the fatigue protocol was applied to both introvert and extrovert indicating increase in angle reconstruction error at the elbow. The rate for this increase was the same after the introvert and extrovert exercise (Allen et al. 2006). • Walsh and colleagues have also reported that the exercise-induced fatigue could decrease the position sense at the elbow that was higher after extrovert exercises than in introvert exercises (Knox & Hodges, 2005). Discussion (Cont.)

17. Generally, fatigue reduces muscle power production as well as impairs neuromuscular coordination. It was also reported that fatigue impairs proprioceptive receptors, especially the activity of the muscle spindles and Golgi tendon organ and also reduces the sensitivity of transferring nerve messages (Hiemstra et al. 2001). • Also, studies have shown that any change in the head and neck due to the disruption in integrating sensory information from the vestibular systems, visual and sensorimotor systems reduces the sense of the elbow (Proske et al. 2000). Discussion (Cont.)

18. Less reconstruction error in the groups after fatigue suggests that people can coordinate fatigue with proprioceptive mechanisms. In fact, in the presence of fatigue, the speed of the stimulation ofmuscle spindles and neurons at motor cortex may bedecreased leading more injury in proprioception. • Another possible factor for the results of this study, the method used to measure the position sense. In our study, elbow joint position sense was measured in space and without contacting the object or any surface, whereas the sense of the shoulder was measured in contact with the surface. This contact can be used as a guide to help the reconstruction angle. Discussion (Cont.)

19. The Conclusions The results of this study showed that fatigue can decrease proprioception in the elbow joint, but this reduction was not seen in shoulder so the shoulder joint position sense was increased. Muscle imbalance, fatigue and reduced proprioception have been identified in many studies as factors causing injury and thus players should performed corrective exercises in order to prevent damage as well as to improve proprioception.

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