Efficacy of Six Weeks Stability Exercises on the Glenohumeral Joint of Female Tennis Players with Scapular Dyskinesia.

Background: Stabilizing exercises reduce pain intensity, improves shoulder position and scapular function, and provides an appropriate strategy for the improvement of scapular dyskinesia. The purpose of this study was to investigate the effect of six weeks of stability exercises (stretching-strengthening) on joint proprioception, strength, and range of motion of the glenohumeral joint in female tennis players with scapular dyskinesia. Methods: Thirty-six female elite tennis players with scapular dyskinesia in both experimental and control groups participated in this study. Goniometer, Isokinetic and Biodex devices were used to evaluate the range of motion, internal and external rotation strength in 60° and 180°, and joint proprioception at 45° and 60°, respectively. Also, the lateral scapular slide test (LSST) was used to evaluate the scapulohumeral rhythm. For analyzing dependent variables and determining statistical significance the ANCOVA and an alpha of 5% was used. Results: The results of this study indicated the effect of the stability exercise program on the range of motion of internal (p = 0.016) and external (p = 0.023) rotation of the shoulder. Also, significant differences were observed between the control and training groups for internal rotation strength 60° (p = 0.013), 180° (p = 0.017) and external rotation strength 60° (p = 0.005), 180° (p = 0.045) and strength ratio 60° (p = 0.001) and 180° (p = 0.023). However, there were no significant differences for proprioception. Conclusion: In general, the findings of this study support the effectiveness of exercise therapy as a safe intervention for improving scapular function in tennis players with scapular dyskinesia.

Effect of Stretching Protocols on Glenohumeral-Joint Muscle Activation in Elite Table Tennis Players.

CONTEXT: Several studies report static-stretch-induced deficits and dynamic-stretch performance improvement after intervention. PURPOSE: To investigate the muscle activation of the forehand and backhand in table tennis players after experiencing static- and dynamic-stretching protocols. METHODS: A total of 24 elite male table tennis players (age 22.7 [3.46] y, height 1.78 [0.03] m) were tested before and 0, 10, 20, and 30 min after the 3 conditions (dynamic stretch, static stretch, and no stretch). The MEGA ME6000 (Mega Electronics, Kuopio, Finland) was used to capture the surface EMG data of the anterior deltoid, middle deltoid, posterior deltoid, biceps, and triceps muscles. Muscle activation data of the pretest were compared with posttest 0, 10, 20, and 30 min. These data were also compared between 3 different conditions (dynamic stretch, static stretch, and no stretch). RESULTS: A 2-way repeated-measures analysis of variance indicated significant differences in the forehand and backhand, and Bonferroni test as a post hoc comparison revealed significant differences between the pretest and posttests in several muscles (P < .05). Furthermore, there were significant differences in the posttest between the 3 conditions (P < .05). CONCLUSIONS: In general, there was a short-term effect of static- and dynamic-stretching protocols on glenohumeral-joint muscle activation in elite table tennis players. The static and dynamic stretching presented a decrease and increase, respectively, in muscle activation up to 30 min after stretching. In conclusion, the additive and subtractive effects of dynamic- and static-stretching protocols on muscle activation seem to persist after 30 min.

Comparison of push-out bond strength of mineral trioxide aggregate and calcium enriched mixture cement as root end filling materials.

BACKGROUND: The purpose of this study was to compare the push-out bond strength of mineral trioxide aggregate (MTA) and calcium enriched mixture (CEM) as root end filling materials. MATERIALS AND METHODS: A total of 40 root dentin slices (1 ± 0.2 mm) were prepared from freshly extracted human maxillary central teeth and their lumens were enlarged to 1.3 mm. The slices were randomly divided into two groups (n = 20). MTA and CEM cement were mixed according to manufacturer's instruction and introduced into the lumens. The specimens were wrapped in pieces of wet gauze soaked in distilled water and incubated at 37°C for 3 days. The push-out bond strength was measured using a universal testing machine. The slices were then examined under a light microscope at ×10 magnification to determine the nature of bond failure. The data were analyzed using Mann-Whitney test (P < 0.001). RESULTS: The mean push-out bond strength for CEM cement and MTA were 1.68 ± 0.9 and 5.94 ± 3.99 respectively. The difference was statistically significant (P < 0.001). The bond failure was predominantly of adhesive type in MTA group and cohesive type in CEM group. CONCLUSION: CEM cement showed significantly lower bond strength to the dentinal wall compared to MTA.