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BACKGROUND: Sitting for a long time causes various postural problems, such as slump sitting. It has been reported that employing a corrected sitting position while lifting the sternum is effective in improving this form of posture. We investigated how a corrected sitting posture with the lifting of the sternum is different from a forced position that is applied through the command and passive positions. MATERIALS AND METHODS: The postural angle of 270 subjects aged 19-23 years was measured in the passive, forced, and corrected positions using a Saunders inclinometer and a Formetric 4D system. RESULTS: As a result, the corrected position had a small range (min-max) at all angles, but the forced position and passive position had a large range (min-max). The lumbar lordosis angle in the corrected position showed positive values throughout its range (min-max), while the other groups showed negative values, which indicates the kyphotic position of the lumbar section. In addition, the percentage error in the corrected position was small, but it presented high values in the other groups. When comparing the average angles between the groups, there were substantial changes observed between the corrected position and the other groups. It was found that the corrected position with the sternum lifted, which is applied to improve slump sitting in the clinical environment, exhibited an angle that differed from that of the forced position and the passive position. CONCLUSIONS: Our results suggest that a forced position on the command "scapular retraction" does not meet the clinical assumptions of posture correction, in contrast to the corrected position with the lifting of the sternum for the improvement of slump sitting. The accurate correction of the position of the sternum and sacrum improves the position of the spine in the sagittal plane, enabling physiological values for the kyphosis and lordosis angle parameters to be obtained. This approach combines the ease of execution and precision of the effect. The fact that this method does not require complex tools to accurately correct the body encourages the implementation of this solution in clinical practice.
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[Purpose] The purpose of this study was to compare the isolation ratios of scapular retraction muscles between protracted scapular and asymptomatic groups. [Subjects] Seven males with protracted scapular and seven asymptomatic males aged 20-30â years were recruited. [Methods] We measeured the rhomboid, middle trapezius (MT), and lower trapezius (LT) muscles activities, and calculated the isolation ratio. [Results] The rhomboid and MT isolation ratio of the protracted scapular group was not significantly different from that of the asymptomatic group. The LT isolation ratio of the protracted scapular group was significantly lower than that of the asymptomatic group. [Conclusion] We suggest that a proper retraction exercise, for patients with protracted scapular posture is one that includes exercises for selectively strengthening the lower trapezius muscle.
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Background: The lower trapezius (LT) muscle, which stabilizes the scapula posteriorly during arm elevation, has been interesting to both clinicians and researchers for its importance in throwing-related shoulder rehabilitation and injury prevention. Purpose: The purpose of this study was to investigate the electromyographic activity of the LT and other relevant muscles during scapular and shoulder activities in the side-lying position. Methods: Twenty collegiate baseball players volunteered to participate in this study. Electromyographic (EMG) output of the lower trapezius, infraspinatus, posterior deltoid, middle deltoid, serratus anterior, and upper trapezius muscles were collected. All the subjects performed isometric resistance exercises in four arm positions: 0° horizontal abduction from the coronal plane (NEUT) with protraction (NEUT-PRO), 15° horizontal adduction from the coronal plane (HADD) with protraction (HADD-PRO), and NEUT with retraction (NEUT-RET), and HADD-RET in a side-lying isometric abduction exercise with two external loads: a 9.1 kg dumbbell and 40% of the manual muscle test (MMT). The subjects also performed two more isometric resistance exercises: supine protraction and side-lying external rotation (ER) of the glenohumeral (GH) joint in GH adduction at 90° of GH ER or with as much ER as possible. All raw EMG data were normalized to maximal voluntary isometric contraction (% MVIC) of the corresponding muscle. Results: LT activity was significantly greater in HADD-RET with 9.1 kg than that of HADD-PRO (p < 0.001) (55 vs 21% MVIC) while middle deltoid muscle activity was significantly decreased in both NEUT and HADD-RET compared to that of NEUT and HADD-PRO (p < 0.001). In contrast, IS muscle activity was significantly increased in HADD-RET with 9.1 kg compared with that 40% MMT (p < 0.001) (41 vs 22% MVIC). Conclusion: LT activity was modulated by changes in scapulothoracic and glenohumeral joint positioning during a side-lying isometric abduction exercise. These findings may help clinicians to select exercises to improve scapular muscle balance ratios during rehabilitation of the shoulder complex. Level of Evidence: Level 3b, Controlled laboratory study.
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Aim: Although the football goalkeepers are overhead athletes, no studies have reported the prevalence of disabled throwing shoulder (DTS) and the shoulder function. Thus, this study aimed to investigate the prevalence of DTS among youth football goalkeepers and to determine the relationship among their shoulder functions. Methods: Youth football goalkeepers, who participated in a pre-participation medical examination were included in the study. The questionnaire was handed out before the examination to determine the players' age, dominant hand, and shoulder pain history. If the player had a history of shoulder pain during ball throwing motion in the past, they were defined as goalkeepers with DTS. Physical examination of scapular positioning, scapular retraction and rotator cuff muscle strength, and ultrasonographic evaluation were performed. Results: Six goalkeepers (16%) had a history of DTS among the 38 male youth football goalkeepers. The presence of scapular malpositioning, limitation of scapular retraction, and decrease in rotator cuff strength was significantly higher in goalkeepers with DTS than in those without DTS (p = 0.03, p < 0.001, p < 0.001, respectively). Three goalkeepers with DTS revealed ultrasonographic findings. Conclusion: The prevalence of DTS among youth football goalkeepers was 16%. All these players had scapular malpositioning and limitation of scapular retraction. Scapular malpositioning and limitation of scapular retraction may be related to the DTS in youth football goalkeepers. Level of evidence: Level IV.
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BACKGROUND: Currently, clinical physical examination maneuvers alone provide variable reliability in diagnosing full-thickness rotator cuff tears (RCTs). PURPOSE: To assess the diagnostic accuracy of the scapular retraction test (SRT) to predict full-thickness RCTs. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 2. METHODS: A total of 331 patients were prospectively evaluated in this cohort study. SRT was performed to assess the status of the rotator cuff. A positive SRT indicates an intact rotator cuff, and a negative SRT indicates a full-thickness RCT. Magnetic resonance imaging (MRI) was used as the gold standard. The examiner was blinded to the results until completing the physical examination. Statistical analysis was performed to assess the sensitivity, specificity, accuracy, positive and negative predictive values, and positive and negative likelihood ratios of the SRT. RESULTS: The prevalence of full-thickness RCTs diagnosed on MRI was 54.4% (180 of 331). Among the 180 patients with an MRI-confirmed full-thickness RCT, the SRT was negative for 147. Of 150 patients with an intact rotator cuff by MRI, 122 had a positive SRT. In diagnosing full-thickness RCTs, the SRT had a sensitivity of 81.7% (95% CI, 77.2%-85.4%), specificity of 80.8% (95% CI, 75.5%-85.3%), and accuracy 81.3%. The positive predictive value was 83.5% (95% CI, 78.9%-87.4%); the negative predictive value, 78.7% (95% CI, 73.5%-83.1%); the positive likelihood ratio, 4.3 (95% CI, 3.1-5.8); the negative likelihood ratio, 0.23 (95% CI, 0.17-0.30); and the diagnostic odds ratio, 18.7 (95% CI, 10.4-34.0). CONCLUSION: The results of this diagnostic study indicate that the SRT can accurately be used to clinically assess the status of the rotator cuff. This physical examination maneuver was found to be accurate, sensitive, and specific in diagnosing full-thickness RCTs. Additionally, our results indicate that it is equally as accurate to predict an intact rotator cuff tendon. Providing an accurate, reliable, and reproducible physical examination test will allow clinicians to diagnosis the integrity of the rotator cuff and will help guide treatment recommendations.