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BACKGROUND: Emerging evidence suggests that the long head of the biceps (LHBT) may play a role in stabilizing the glenohumeral joint, and this has led to controversy around the efficacy of biceps tenotomy for superior labral anterior and posterior (SLAP) lesions. Therefore, the aim of this finite element analysis (FEA) study was to determine the stress absorption and humeral head translation restriction effects of the LHBT within the glenohumeral joint during the late cocking and deceleration phases of overhead throwing with a view to resolving the controversy around tenotomy. METHODS: Eight FEA models were created using computed tomography and magnetic resonance imaging data from normal glenohumeral joints. The models represented four LHBT conditions: uninjured, subpectoral tenodesis, tenotomy, and type II SLAP lesions. The late cocking and deceleration phases of the overhead throwing were simulated for each model. The impacts of the four LHBT conditions on glenohumeral joint stress absorption and humeral head displacement restriction were studied based on 1) stress and related distributions on the cartilage, labrum, capsule, and LHBT and 2) humeral head translation variation. RESULTS: The FEA analysis showed that the magnitude of the contact stress on the articular cartilage, labrum, and capsule was the lowest in the uninjured models, followed by the subpectoral tenodesis, tenotomy, and type II SLAP lesion models. Humeral head translation was the most restricted in the subpectoral tenodesis models, followed by the tenotomy and type II SLAP lesion models. CONCLUSION: Finite element analysis demonstrated that the LHBT plays a significant role in stress absorption and displacement restriction in the late cocking and deceleration phases of overhead throwing. Subpectoral tenodesis of the LHBT exhibited lesser amount of stress and humeral head translation than those of tenotomy, thereby making it a better option for patients who engage in overhead throwing.
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Background: The morphological changes in the posterior glenoid rim are unknown in relation to the area of rotator cuff tendons pinched within the glenohumeral joint in the throwing shoulders of baseball players. Therefore, this study aimed to clarify whether these changes are associated with the area of impingement in baseball players. Methods: Overall, 25 asymptomatic male college baseball players (average age19.8 years, 11.6 years of competing, and 50 shoulders) participated in this study. The area of impingement (AOI, mm2) and posterior glenohumeral distance (PGHD, mm) were measured using magnetic resonance imaging to quantitatively assess the impingement area of the rotator cuff tendon within the glenohumeral joint and the morphologic change in the posterior glenoid rim. These magnetic resonance imaging assessments were measured at 90° shoulder abduction with 90° and 100° external rotation. Multiple linear regression analysis was performed to determine whether AOI is predicted by PGHD. Findings: Multiple linear regression analysis showed that the PGHD was a predictor of the AOI at external rotation 90° (ß-coefficient = 0.738, R2 = 0.77, P < 0.001) and external rotation 100° position (ß-coefficient = 0.879, R2 = 0.76, P < 0.001). Interpretation: This study found that the area of impingement was associated with posterior glenohumeral distance. Therefore, these findings may indicate that complex shoulder joint morphologic changes result in a disabled throwing shoulder.
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Background: The shoulder motion during pitching is influenced by the trunk and pelvis motions, but their relationship during the deceleration phase of throwing on flat ground has not yet been clarified. This study aimed to investigate the relationship between shoulder, trunk, and pelvis kinematics at the maximum internal rotation (MIR) of the shoulder during the deceleration phase of throwing on flat ground. Methods: The study participants included 17 male baseball players over 20 years old and at the recreational playing level. The recreational level was illustrated by players who did not practice at high intensity and had played only 1-2 competitions per week. Reflective markers were applied to the subject, and throwing motion was assessed using a three-dimensional motion capture system. Data were captured at 1000 Hz. We assessed the angle of the shoulder, spine, and pelvis at the MIR on flat ground. Internal shoulder rotation velocity and spinal and pelvic angular velocities were also assessed. The relationship between the shoulder, spine, and pelvis kinematics at the MIR was examined using simple linear regression analysis. Results: The internal shoulder rotation angle at the MIR was negatively associated with only the spinal flexion and rotation angle at the MIR (P = .006 and P = .010, respectively). No other significant associations between shoulder, spine, and pelvis kinematics were detected at the MIR. Conclusion: For throwing on flat ground, the internal shoulder rotation motion may be suppressed by producing trunk flexion and rotation motion at the MIR.
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PURPOSE OF REVIEW: The management of shoulder instability in throwing athletes remains a challenge given the delicate balance between physiologic shoulder laxity facilitating performance and the inherent need for shoulder stability. This review will discuss the evaluation and management of a throwing athlete with suspected instability with a focus on recent findings and developments. RECENT FINDINGS: The vast majority of throwing athletes with shoulder instability experience subtle microinstability as a result of repetitive microtrauma rather than episodes of gross instability. These athletes may present with arm pain, dead arms or reduced throwing velocity. Recent literature reinforces the fact that there is no "silver bullet" for the management of these athletes and an individualized, tailored approach to treatment is required. While initial nonoperative management remains the hallmark for treatment, the results of rehabilitation protocols are mixed, and some patients will ultimately undergo surgical stabilization. In these cases, it is imperative that the surgeon be judicious with the extent of surgical stabilization as overtightening of the glenohumeral joint is possible, which can adversely affect athlete performance. Managing shoulder instability in throwing athletes requires a thorough understanding of its physiologic and biomechanical underpinnings. Inconsistent results seen with surgical stabilization has led to a focus on nonoperative management for these athletes with surgery reserved for cases that fail to improve non-surgically. Overall, more high quality studies into the management of this challenging condition are warranted.
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The strength of the shoulder musculature involved with internal rotation and arm extension plays an important role in the overhead throwing motion for baseball athletes, both for throwing-related performance and injury risk. The maintenance of shoulder strength is a high priority for baseball athletes throughout a season; however, little is known in regards to the expected changes in strength throughout a season. To examine pre-post changes in shoulder strength, lower body power, and body composition among collegiate baseball players after the completion of a summer baseball league season. Amateur baseball players (n = 12; age: 20.9 ± 1.0 years.; height: 181.6 ± 5.6 cm; body mass: 86.4 ± 11.1 kg; BMI: 26.0 ± 2.6 kg/m2) participated in the current study. Pre- and post-competitive season, the participants completed shoulder strength assessments and body composition and countermovement vertical jump (CMJ) tests. An upper-body isometric test (athletic shoulder [ASH] test) was used to evaluate shoulder strength for each arm. Each subject completed maximal isometric contractions for both the throwing and non-throwing arms at four separate angles of abduction (180°, 'I'; 135°, 'Y'; 90°, 'T'; and -180°, 'A') while lying in a prone position. For shoulder strength, the primary dependent variable of interest was a composite measure that represented the average of the forces produced across all four positions of the ASH test (I, Y, T, A). For the ASH test composite measure, there was a trend toward a significant arm-by-time interaction effect (p = 0.08), as shoulder strength decreased by 9.03% for the throwing arm (ES = 0.72; 95% CI = [-0.27, -0.01]), compared to only 2.03% for the non-throwing arm (ES = 0.15; 95% CI = [-0.16, 0.09]), over the course of the season. The main effects of time (p = 0.16) and arm (p = 0.58) were not significant for the ASH test composite measure. There was no relationship between lower body power and throwing arm strength at baseline (r = 0.20, p = 0.56), and only a non-significant weak relationship at post-test (r = 0.28, p = 0.41). Throughout a season, baseball players may experience reductions in shoulder strength of the throwing arm with minimal changes in shoulder strength in the non-throwing arm.
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Previous research has shown that action effects of self-generated movements are internally predicted before outcome feedback becomes available. To test whether these sensorimotor predictions are used to facilitate visual information uptake for feedback processing, we measured eye movements during the execution of a goal-directed throwing task. Participants could fully observe the effects of their throwing actions (ball trajectory and either hitting or missing a target) in most of the trials. In a portion of the trials, the ball trajectory was not visible, and participants only received static information about the outcome. We observed a large proportion of predictive saccades, shifting gaze toward the goal region before the ball arrived and outcome feedback became available. Fixation locations after predictive saccades systematically covaried with future ball positions in trials with continuous ball flight information, but notably also in trials with static outcome feedback and only efferent and proprioceptive information about the movement that could be used for predictions. Fixation durations at the chosen positions after feedback onset were modulated by action outcome (longer durations for misses than for hits) and outcome uncertainty (longer durations for narrow vs. clear outcomes). Combining both effects, durations were longest for narrow errors and shortest for clear hits, indicating that the chosen locations offer informational value for feedback processing. Thus, humans are able to use sensorimotor predictions to direct their gaze toward task-relevant feedback locations. Outcome-dependent saccade latency differences (miss vs. hit) indicate that also predictive valuation processes are involved in planning predictive saccades.NEW & NOTEWORTHY We elucidate the potential benefits of sensorimotor predictions, focusing on how the system actually uses this information to optimize feedback processing in goal-directed actions. Sensorimotor information is used to predict spatial parameters of movement outcomes, guiding predictive saccades toward future action effects. Saccade latencies and fixation durations are modulated by outcome quality, indicating that predictive valuation processes are considered and that the locations chosen are of high informational value for feedback processing.
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Fijación Ocular , Objetivos , Desempeño Psicomotor , Movimientos Sacádicos , Humanos , Masculino , Femenino , Adulto , Desempeño Psicomotor/fisiología , Movimientos Sacádicos/fisiología , Fijación Ocular/fisiología , Adulto Joven , Retroalimentación Sensorial/fisiologíaRESUMEN
BACKGROUND: Identification of the relationship between valgus stress in the medial elbow and ulnar nerve strain during maximum external rotation of the shoulder is pivotal for the prevention and management of ulnar neuropathies. In this observational cross-sectional study, we aimed to determine the changes in ulnar nerve stiffness under valgus stress at different nerve entrapment sites. METHODS: Twenty healthy baseball players participated in the study. The stiffness of the ulnar nerve on the throwing side was assessed at two sites, the arcade of Struthers and the Osborne's ligament, at 0°, 60°, and 90° flexion by shear wave elastography using a 10-MHz linear transducer. The arcade of Struthers was defined as the proximal site and the Osborne's ligament as the distal site. Valgus stress was applied to the medial elbow at 0, 30, 50, and 70 N using a Telos stress device, and the stiffness caused by valgus stress was measured. RESULTS: At all elbow flexion angles, the stiffness of the ulnar nerve under 70 N valgus stress was higher than that under 30 N stress. The stiffness of the ulnar nerve at the proximal site was significantly higher than that at the distal site. CONCLUSION: Valgus stress increases ulnar nerve stiffness. In addition, the stiffness of the proximal site increases.
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Underarm throwing motions are crucial in various sports, including boccia. Unlike healthy players, people with profound weakness, spasticity, athetosis, or deformity in the upper limbs may struggle or find it difficult to control their hands to hold or release a ball using their fingers at the proper timing. To help them, our study aims to understand underarm throwing motions. We start by defining the throwing intention in terms of the launch angle of a ball, which goes hand-in-hand with the timing for releasing the ball. Then, an appropriate part of the body is determined in order to estimate ball-throwing intention based on the swinging motion. Furthermore, the geometric relationship between the movements of the body part and the release angle is investigated by involving multiple subjects. Based on the confirmed correlation, a calibration-and-estimation model that considers individual differences is proposed. The proposed model consists of calibration and estimation modules. To begin, as the calibration module is performed, individual prediction states for each subject are updated online. Then, in the estimation module, the throwing intention is estimated employing the updated prediction. To verify the effectiveness of the model, extensive experiments were conducted with seven subjects. In detail, two evaluation directions were set: (1) how many balls need to be thrown in advance to achieve sufficient accuracy; and (2) whether the model can reach sufficient accuracy despite individual differences. From the evaluation tests, by throwing 20 balls in advance, the model could account for individual differences in the throwing estimation. Consequently, the effectiveness of the model was confirmed when focusing on the movements of the shoulder in the human body during underarm throwing. In the near future, we expect the model to expand the means of supporting disabled people with ball-throwing disabilities.
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Movimiento , Hombro , Humanos , Movimiento/fisiología , Hombro/fisiología , Fenómenos Biomecánicos/fisiología , Masculino , Adulto , AlgoritmosRESUMEN
Overhead athletes undergo significant biomechanical adaptations due to repetitive overhead movements, primarily affecting the glenohumeral joint. These adaptations can lead to glenohumeral internal rotation deficit (GIRD), which is characterized by posterior capsule stiffness that results in glenohumeral joint translation and a shift in the center of gravity. The severity of GIRD is dependent upon the presence of asymmetry between gained external and lost internal rotation, which is defined clinically as an asymmetry exceeding 20º; this reduces the total range of motion compared to the unaffected limb or baseline measurements. Diagnosis is challenging, as it can be mistaken for chronic scapular adaptations. To mitigate misdiagnosis, a high clinical suspicion is crucial in overhead athletes, especially those who began performing forceful overhead movements before closure of growth plates. Periodic physical examinations should establish baseline values for glenohumeral rotation and track changes in glenohumeral motion to aid in diagnosis. Symptoms of GIRD include shoulder pain, stiffness, and decreased force exertion. Magnetic resonance imaging is the preferred imaging method for evaluating GIRD and assessing concomitant soft tissue pathologies. Untreated GIRD can lead to rotator cuff strength imbalances. Treatment mainly involves conservative measures, such as physical therapy, to improve internal rotation and alleviate posterior tightness. Surgical interventions are considered when symptoms persist despite conservative treatment with physical therapy or in the presence of concomitant pathologies.
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BACKGROUND: Throwing is one of the most important movement in handball. Throwing performance is crucial for success in handball. OBJECTIVE: Τo investigate the level of evidence for the effect of resistance training (RT) on throwing performance in handball players. METHODS: Systematic searches of Pubmed, Medline complete, Cinahl, Sport Discus and Scopus were undertaken for peer reviewed articles published between 18 March 1995 to 18 March 2023. Randomized, controlled, clinical studies, written in English, aiming to investigate the effect at least one modality of RT on throwing performance (velocity or/and accuracy) in handball players were considered for inclusion in the study. The eligible studies were assessed for methodological quality using the Physical Therapy Evidence Database (PEDRO) scale. The Best Evidence Synthesis (BES) approach was used for synthesizing and reporting the results. Furthermore, the random-effects model was used for the meta-analysis and the Q-statistic was used to test the null hypothesis that all studies in the analysis share a common effect size. RESULTS: One hundred ninety-eight studies were identified, of which 30 were included. A total of 727 handball players (males = 388, females = 292) were included. 28 of the 30 studies were rated as high methodological quality studies (PEDRO score > 70%) while the rest of the studies were rated as moderate methodological quality studies (PEDRO score ≤ 60%). The mean effect size for the effectiveness of resistance training (RT) in improving jumping throw, running throw, and standing throw velocity were 1.128 (95% CI 0.457 - 1.798), 1.756 (95% CI 1.111 - 2.400), and 1.098 (95% CI 0.689 - 1.507) correspondingly. Traditional weight training using barbells in mostly compound lifts yielded the most significant and robust results. Other RT modalities such as elastic bands, medicine balls, core training and ballistic training showed no significant results or positive effects due to the limited number of the studies. CONCLUSION: Strong evidence exists only for the effectiveness of RT using barbells in increasing throwing velocity. In contrast, the remaining RT modalities, while yielding positive results, have limited support due to limited number of studies and the high heterogeneity between studies. Furthermore, there is insufficient evidence to support various forms of RT in increasing throw distance. Finally, medicine ball training and elastic band training demonstrated no benefits in improving throwing accuracy. TRIAL REGISTRATION: PROSPERO ID: CRD42023393574.
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Shoulder injuries are common in baseball pitchers and primarily involve the glenohumeral joint. Past analyses have examined shoulder biomechanics during different pitch types simply as the motion of the upper arm relative to the thorax. In this study, glenohumeral and scapulothoracic kinematics were compared between fastballs and curveballs at key timepoints throughout a pitch. Upper extremity kinematics of thirteen collegiate pitchers were collected during fastball and curveball pitches with motion capture. A linear model approach was utilised to estimate scapular kinematics based on measurable humerothoracic motion. Glenohumeral kinematics were computed from the scapular and humeral motion data. Comparisons of scapulothoracic and glenohumeral kinematic variables at times of maximum glenohumeral external rotation, ball release, and maximum glenohumeral internal rotation between pitch types were made using paired t-tests with Benjamini-Hochberg corrections. There were no significant differences in glenohumeral kinematics. Fastballs elicited significantly less scapulothoracic internal rotation and more posterior tilt at maximum glenohumeral external rotation. Fastballs produced significantly less scapulothoracic internal rotation and anterior tilt at maximum glenohumeral internal rotation. This study provides further evidence that risk of injury to the glenohumeral joint may be consistent between fastballs and curveballs and offers insights into subtle differences in scapular kinematics between pitch types.
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Background: A strong body of literature has been published outlining muscle activity differences during sports performance in groups of overhead athletes. However, there are limited studies that have directly compared the muscle activity in overhead athletes with and without history of shoulder injury during functional everyday tasks. Purpose: This study aimed to identify muscle activities across fourteen upper extremity and core muscles during three functional everyday movements in athletes with and without history of shoulder injury. Study Design: Cross-Sectional Study. Methods: Thirty-two male overhead throwing athletes (fifteen healthy and seventeen injured) were recruited and completed three everyday functional movements of high elevation, low elevation, and rotation, using their dominant arm to move an object between two fixed positions. Electromyography (EMG) was recorded for fourteen muscles including: biceps brachii, deltoids (anterior, medial, and posterior), trapezius (upper and lower), pectoralis major, latissimus dorsi, serratus anterior, infraspinatus, external obliques, and gluteus maximus (all surface electrodes) and supraspinatus (fine wire electrode). Mixed model repeated measures ANOVA and post-hoc analysis assessed mean muscle activity (%MVC) between groups and each movement phase. Results: Upper trapezius elicited higher mean activity in healthy athletes during both phases of the arm rotation task (p \< 0.05). No differences between groups were evident for arm elevation tasks. Qualitative analysis of muscle patterns during functional tasks reflected a temporal shift in muscle activation timings and magnitudes between athlete groups, suggesting potential compensatory mechanisms in injured athletes. Conclusion: Injured overhead athletes appear to utilize other upper limb and shoulder girdle muscles to compensate for lower upper trapezius activity during functional everyday tasks. Level of Evidence: 3.
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Objectives: The objective is to compare stiffness changes around the shoulder muscles between pitchers and position players after throwing overhead using shear wave elastography (SWE) in relation to throwing motion analysis and muscle strength. Methods: A total of 32 male college baseball players (12 pitchers and 20 position players) were observed throwing 20 times, and SWE was performed to evaluate 13 shoulder muscle items-tendons (supraspinatus, infraspinatus, subscapularis, and teres minor), muscles (supraspinatus, infraspinatus [transverse and oblique part], teres minor, lower trapezius, latissimus dorsi, and pectoralis minor), and capsules (posterior and posteroinferior). Motion analysis was used to assess elbow torque, forearm angle, forearm rotation speed, and maximum external rotation angle of the shoulder. Muscle strength was measured using a dynamometer for abduction, internal/external rotation of the shoulder at an abduction of 0°, internal/external rotation of the shoulder at an abduction of 90°, and internal/external rotation of shoulder at a flexion of 90°. Results: In the pitcher group, SWE values for the teres minor muscle and latissimus dorsi muscle increased significantly after throwing. In the position player group, SWE values for the teres minor muscle significantly increased, and SWE values of the pectoralis minor muscle decreased after throwing. In the pitcher group, positive correlations were found between the teres minor muscle and forearm rotation speed and between the latissimus dorsi muscle and forearm angle. No significant difference was found in muscle strength after throwing in any of the groups. Conclusions: Stiffness changes occurred after throwing and were related to the motion analysis, but the regions in which stiffness occurred varied between pitchers and position players.
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STUDY DESIGN: A retrospective, cross-sectional study was conducted to analyze the implications of asymmetric baseball movements on the incidence of spondylolysis. PURPOSE: This study aimed to evaluate the relationship between asymmetric movements and the laterality of spondylolysis. OVERVIEW OF LITERATURE: Baseball, characterized by its asymmetric throwing and batting, may disproportionately stress one side. Lumbar spondylolysis is a frequent cause of lower back pain in young athletes, particularly those involved in activities with consistent unilateral rotations such as baseball. However, whether a link exists between the laterality in spondylolysis and the dominant throwing/ batting side or whether disparities exist between pitchers and fielders remains unclear. METHODS: The study included 85 players. Participants were divided into two groups: pitchers and fielders. The association between the laterality of spondylolysis and the throwing/batting side in the overall cohort and between the two groups was evaluated. RESULTS: Among pitchers, 16 lesions appeared on the throwing side and 32 on the nonthrowing side (p =0.029). For fielders, no notable difference was observed between the two sides (p =0.363). Furthermore, batting preference did not influence the laterality of spondylolysis in either group. CONCLUSIONS: Adolescent baseball players, particularly pitchers, exhibited a higher incidence of lumbar spondylolysis on the side opposite their throwing arm. The findings of this study highlight the significant effect of asymmetrical sporting activities on the development of spondylolysis, to which pitchers are particularly susceptible.
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CONTEXT: The quality and interprogram variability of publicly available throwing programs have not been assessed. OBJECTIVE: To (1) identify publicly available interval throwing programs, (2) describe their components and structure, and (3) evaluate their quality, variability, and completeness. DATA SOURCES: Google, Bing, Yahoo; keyword: "interval throwing program." STUDY SELECTION: Baseball-specific publicly available programs. STUDY DESIGN: Systematic review. LEVEL OF EVIDENCE: Level 4. DATA EXTRACTION: Independent evaluation by 2 authors using a novel 21-item Quality Assessment Rubric (QAR). RESULTS: Of the 99 included programs, 54% were designed for return from injury/surgery; 42% explicitly stated no expected timeline for completion, and approximately 40% did not provide criteria to initiate the program. Program construction was highly variable. There were broad-ranging shortest (mean: 40±8 ft, range: 20-45 ft) and longest (mean: 150±33 ft, range: 90-250 ft) long toss distances, and variable maximum numbers of mound pitches thrown before returning to game play (range: 40-120, mean: 85). Only 63% of programs provided guidelines for handling setbacks, and standardized warm-ups, arm care, and concomitant training were absent in 32%, 63%, and 47% of programs, respectively. Mean QAR completion rate and QAR item response rate were low (62 ± 4% [range, 24-91%], 62 ± 24% [range, 7-99%], respectively). Finally, only 20 (20%) programs provided at least 1 peer-reviewed reference, most of which were published >10 years ago. CONCLUSION: Publicly available interval throwing programs are readily available but demonstrate significant interprogram heterogeneity across multiple areas including target audience, program construction, progression, and execution. The quality and consistency of publicly available interval throwing programs is poor at this time, which may limit their utility and effectiveness for baseball players attempting to return to competition. This work identifies a multitude of deficiencies in currently available throwing programs that should be targets of future improvement efforts.
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Osteochondritis dissecans of the capitellum is debilitating and is a potentially sports career-ending injury in a young and athletic population. Osteochondritis dissecans typically occurs in patients between the ages of 10 and 24 years, and boys are more commonly affected than girls. Conventional radiographs have low diagnostic accuracy, and magnetic resonance imaging (with or without contrast) or computed tomography may aid in accurate diagnosis. The primary indication for non-operative treatment is the presence of an intact cartilage cap on magnetic resonance imaging, indicating a "stable lesion." However, if operative treatment is necessary, various surgical procedures are available when operative treatment for an osteochondritis dissecans of the capitellum is considered, including open or arthroscopic removal of loose bodies, with or without microfracturing, fragment fixation, osteochondral autograft transplantation, and osteochondral allograft transplantation. The decision-making process for selecting the appropriate treatment considers factors such as the patient's characteristics, functional limitations, and lesion morphology.
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Background: The region where the ulnar nerve (UN) is swollen in baseball players with ulnar neuropathy is not apparent. This study investigated the UN's cross-sectional area (CSA) at each entrapment point in baseball players. We also aimed to clarify the relationship between valgus instability and the CSA of the UN. Methods: Forty baseball players were separated into healthy and ulnar neuropathy groups. The CSA and valgus instability were measured using ultrasonography (US). Relative to the medial epicondyle (MEC), the arcade of Struthers (SA) was 5â cm proximal, the cubital tunnel was the posterior part, and Osborne's ligament was defined as 3â cm distal. The ulnohumeral joint space was imaged as a low-echo space between the distal-medial corner of the trochlea and the proximal edge of the sublime tubercle. Results: The UN in the ulnar neuropathy group had significant swelling in the cubital tunnel and Osborne's ligament. We found a weak positive correlation between the CSA and ulnohumeral joint space, and the ulnohumeral joint space at rest and valgus stress. Conclusion: Evaluation and treatment of UN, especially cubital tunnel and Osborne's ligament, are necessary for the rehabilitation of baseball players presenting with ulnar neuropathy and valgus instability.
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While it is well known that mental fatigue impairs fine motor performance, the investigation into its neural basis remains scant. Here, we investigate the impact of mental fatigue on fine motor performance and explore its underlying neural network connectivity mechanisms. A total of 24 healthy male university students were recruited and randomly divided into two groups: a mental fatigue group (MF) and a control group (Control). Both groups completed 50 dart throws, while electroencephalography (EEG) data were collected. Following the Stroop intervention, participants in the MF group exhibited a decrease in Stroop task accuracy and throwing performance, and an increase in reaction time along with VAS and NASA scores. The EEG data during dart-throwing revealed that the network connectivity strength of theta oscillations in the frontal and left central regions was significantly higher in the MF group compared with the Control group, while the network connectivity strength of alpha oscillations in the left parietal region was significantly enhanced. The interregional connectivity within the theta and alpha rhythm bands, particularly in the frontal-central-parietal network connections, also showed a significant increase in the MF group. Mental fatigue impairs dart throwing performance and is accompanied by increased connectivity in alpha and theta.
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Electroencefalografía , Lóbulo Parietal , Humanos , Masculino , Tiempo de Reacción , Ritmo alfa , Fatiga MentalRESUMEN
[Purpose] This study aimed to investigate the changes in the trunk and pelvic lateral tilt angles at the shoulder's maximum external rotation during the late cocking phase (MER) and ball release (BR) and hip muscle strength during repetitive throwing. [Participants and Methods] In this study, 12 male baseball players participated. During the throwing, which was filmed using a high-speed video camera, the trunk and pelvic lateral tilt angles toward the nonthrowing side were measured at the MER and BR. Hip muscle strength during abduction, adduction, and external internal rotations were measured on the throwing and nonthrowing sides. Repetitive throwing was performed for nine innings, with 15 pitches per inning. Throwing motion was compared during innings 1, 7, 8, and 9. Hip muscle strength was measured before and after repetitive throwing. [Results] Compared with the trunk lateral tilt angle toward the nonthrowing side at BR in inning 1, the angle in innings 8 and 9 increased. The strength of hip abduction, adduction, and external and internal rotations on the throwing and nonthrowing sides decreased after repetitive throwing. [Conclusion] Hip muscle strength decreases after 135 pitches, and throwing >120 pitches changes the trunk lateral tilt angle at BR.
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Background: An olecranon stress fracture (OSF) is a rare injury most commonly seen in high-level overhead throwing athletes with no clear consensus on surgical treatment. The most common surgical treatment described in the literature is cannulated screw fixation but there have been high rates of reported hardware irritation and need for subsequent hardware removal. Hypothesis/Purpose: This study describes a novel surgical technique in the treatment of OSFs in high-level throwing athletes using retrograde headless compression screws. We hypothesized that patients would have excellent outcomes and decreased rates of hardware irritation postoperatively. Methods: A retrospective review of competitive-level throwing athletes who sustained OSFs that were treated operatively using a novel technique using retrograde cannulated headless compression screws to avoid disruption of the triceps tendon. Postoperative outcome measures obtained included the Disabilities of the Arm, Shoulder and Hand score, Mayo Elbow Performance Score, Simple Elbow Test score, Single Assessment Numerical Evaluation score, Visual Analog Scale, arch of motion, and time to return to sport as well as level returned to. Radiographs were obtained routinely at 2-week, 6-week, 12-week, 6-month, 1-year, and 2-year follow-up. Results: Five of 5 patients who met inclusion criteria were available for final follow-up. Mean age at time of surgery was 20 years (range 17-24). Mean follow-up was 17 months (range 4-33). All patients were baseball players, 4 of which were pitchers and 1 position player. All patients were able to return to sport at the same level or higher at a mean of 5.8 months (range 3-8). Postoperatively, mean arch of motion was 138°, Visual Analog Scale score was 0, Single Assessment Numerical Evaluation score was 90, Disabilities of the Arm, Shoulder and Hand score was 2.0, Mayo Elbow Performance Score was 100, and Simple Elbow Test score was 12. There was no incidence of hardware removal. Conclusion: This study presents a novel surgical technique in the treatment of OSFs in high-level throwing athletes. The results presented demonstrate that this technique is safe and effective for getting athletes back to play quickly without any complications of hardware irritation which has previously shown to be a significant problem in prior literature.