Association of Head-Neck Rotation With History of Pitching-Related Elbow Pain in Youth Baseball Players.

Background: Prevention of pitching-related elbow pain in youth baseball players is important. Overhead pitching involves a whole-body motion, including head-neck rotation. A limited range of motion of head-neck rotation may cause inefficient pitching motion; however, this association is unclear. Purpose: To determine whether the range of motion of head-neck rotation is associated with the history of pitching-related elbow pain in youth baseball players. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A total of 311 youth baseball players were selected and asked to complete a questionnaire survey about their age, weight, height, sex, baseball experience, main position, pitching side, and previous/current elbow pain during pitching. The range of motion of the upper and lower limb joints, head-neck rotation, and thoracic kyphosis angle were measured. Binomial logistic regression analysis was used to identify factors associated with the history of elbow pain related to pitching. Results: There were 101 players with a history of pitching-related elbow pain (history group) and 142 players with no pitching-related elbow pain (no-history group). The history group had significantly lower values than the no-history group regarding the range of motion of head-neck rotation on the nondominant side (74.9°± 9° vs 77.7°± 9.6°; P = .02) and overall head-neck rotation (150.6°± 14.7° vs 154.9°± 18.4°; P = .04). Binomial logistic regression analysis identified head-neck rotation on the nondominant side (odds ratio [OR], 0.97 [95% CI, 0.94-1.00]), shoulder horizontal adduction on the dominant side (OR, 0.98 [95% CI, 0.96-1.00]), height (OR, 1.04 [95% CI, 1.00-1.08]), and playing position (pitcher) (OR, 0.40 [95% CI, 0.21-0.76]) as factors associated with a history of pitching-related elbow pain. Conclusion: Our cross-sectional analysis demonstrated that youth baseball players with a history of pitching-related elbow pain had limited head-neck rotation range of motion on the nondominant side, and this was a significant factor associated with the history of pitching-related elbow pain.

Medial elbow joint space gapping associated with repetitive baseball pitching in preadolescent baseball players.

BACKGROUND: The baseball pitching motion creates valgus stress to the medial elbow, which contributes to increased medial elbow joint space gapping. The musculoskeletal systems of preadolescent baseball players are immature compared with those of adults, but it is unclear whether the repetitive pitching action causes an increase in medial elbow joint space gapping. This study aimed to examine differences in medial elbow joint space gapping based on the pitch count of preadolescent baseball players compared with those of adult players. METHODS: The participants were 11 healthy preadolescent baseball players and 12 college students with baseball experience. They threw 60 maximal-effort pitches arranged into 4 sets of 15 pitches. The medial elbow joint space was measured ultrasonographically with the forearm weight before pitching and following every set of 15 pitches. Repeated-measures analysis of variance and the Bonferroni post hoc test were used to compare the medial elbow joint space among the 5 pitching sets (before pitching and after 15, 30, 45, and 60 pitches) and between the groups of preadolescent baseball players and college students. RESULTS: There was no significant change in the medial elbow joint space gapping of the dominant elbow based on age/pitch count (F = 0.42, P = .796). There was a significant effect of pitch count (F = 30.28, P < .001) and between-group effects (F = 4.56, P = .045). The medial elbow joint space gapping increased significantly after 60 pitches in preadolescent baseball players (P = .023) and college students (P = .021). The medial elbow joint space gapping in preadolescent baseball players was significantly wider than that in college students (P = .007 before pitching, P = .027 at 15 pitches). CONCLUSION: Sixty repetitive pitches contributed to an increase in the medial elbow joint space gapping, regardless of age. The results of this study provide further evidence when considering pitching limitations.

Ultrasonographic prevalence of ulnar nerve displacement at the elbow in young baseball players.

BACKGROUND: Overhead-throwing athletes are at risk of elbow injury because of valgus stress, leading to unstable ulnar nerves and neuropathy. Studies regarding ulnar nerve damage/displacement have been performed primarily in adults. OBJECTIVE: To determine the prevalence and related factors associated with ulnar nerve displacement at the elbow in young baseball players. DESIGN: Cross-sectional study. PARTICIPANTS: Youth baseball players ages 10-12 years were eligible to participate. Exclusion criteria were history of neuropathic pain, trauma, or prior surgery of the upper limb. Fifty-seven participants were eligible for inclusion in the study. MAIN OUTCOME MEASUREMENTS: Demographic data and ultrasonography findings of ulnar nerve dynamics at the cubital tunnel were analyzed in a total of 114 elbows. Elbows were grouped into nondislocation and displacement (subluxation or dislocation) groups according to ultrasound findings. Logistic generalized estimating equations were used to identify factors associated with ulnar nerve displacement. RESULTS: Thirty-six (31.6%) elbows demonstrated sonographic findings of ulnar nerve displacement, with 13 (11.4%) subluxations and 23 (20.2%) dislocations. Fourteen (24.6%) participants experienced nerve displacement in the dominant elbow only, whereas nerve displacement in both elbows occurred in 11 (19.3%) participants. Nerve displacement in the nondominant elbow only was not observed. Hand dominance and tenderness of the arcade of Struthers' were factors associated with ulnar nerve displacement (odds ratio, 2.81, and 9.73; 95% confidence interval, 1.34-5.91 and 2.45-38.68; p = .006 and .001, respectively). CONCLUSION: One-third of the young baseball players evaluated had ultrasonographic findings compatible with ulnar nerve displacement at the elbow. Hand dominance and tenderness of Struthers arcade were the only factors associated with ulnar nerve displacement. Ultrasound may help identify patients with ulnar nerve displacement and contribute to the understanding of its pathophysiology in young baseball players.

Adaptation of the acetone method for the δ15 N-NO3 - analysis of saline water with a low concentration of nitrate.

RATIONALE: The recently reported acetone method for δ15 N-NO3 - analysis is a straightforward sample preparation process. However, the applicability of the method to water samples having high salinity and low concentration of nitrates is not good. Therefore, we developed a new method to measure δ15 N-NO3 - values in a saline sample having low nitrate concentration by improving the acetone method (the adapted method), and verified its usability. METHODS: The adapted method involves (a) reducing a large volume of sample by evaporation, (b) removing NaCl by mixing acetone twice, (c) changing the volume ratio of the acetone/NaI/n-hexane solvent from 21/0.35/10 to 30/0.25/5 mL, (d) using an increased volume of BaI2 (0.1 M) - from 0.75 to 1 mL, and (e) using an alternative capsule drying process of lyophilization. RESULTS: The adapted method has provided nearly exact δ15 N-NO3 - values of standard materials with high precision and accuracy (<0.1‰) at a lower cutoff of 2 µmol of NO3 - in a sample capsule. The recovery of NO3 - in this method was significantly dependent (P < 0.05) on the Cl- concentration of the samples. However, a minimum recovery of 60% NO3 - , required for the reproducibility of the accurate value of δ15 N-NO3 - , was possible from the concentrated sample aliquot containing up to 6 g of Cl- . The application of the adapted acetone method to creek water samples, collected from mangrove watersheds, has shown high consistency in the analysis results. CONCLUSIONS: It was proved that the inexpensive and easy-to-handle adapted acetone method could be used for the δ15 N-NO3 - analysis of saline water samples when the sample aliquot contained about 4 µmol of NO3 - with less than 6 g of Cl- .

Reproducibility and validity of the Japanese version of the Western Ontario Rotator Cuff Index.

BACKGROUND: The Western Ontario Rotator Cuff Index (WORC) is a self-report, disease-specific, quality-of-life assessment tool. Good reliability and validity have been demonstrated with several language versions of the WORC. In this study, the WORC was translated into Japanese, and its reproducibility and validity for use in Japanese patients with rotator cuff disorder were determined. MATERIALS AND METHODS: The translated version of the WORC was certified by the developer of the original version. Of 78 consecutive Japanese patients with rotator cuff disorder, 75 completed the following questionnaires: the WORC; the Disabilities of the Arm, Shoulder, and Hand (DASH); and the Short Form 36 (SF-36). In total, 50 patients completed the WORC twice within 2-14 days. Internal consistency, test-retest reliability, absolute reliability, and construct validity were assessed. RESULTS: Cronbach's alpha coefficients ranged from 0.78-0.95, and intraclass correlation coefficients ranged from 0.72-0.84 for the total score as well as scores on all WORC domains. A fixed bias was revealed between the test and retest for the total score and scores of some domains. Limits of agreement (LOA) ranged from -19.0-27.9% for the total score on the WORC. Furthermore, the WORC scores correlated with those of DASH (r = 0.63-0.78) and SF-36 (r = -0.24 to -0.69). CONCLUSIONS: Good test-retest reliability and construct validity were demonstrated for the Japanese WORC, but relatively high absolute measurement errors were observed. LOA values must be considered when using the WORC for individual patients with rotator cuff disorder.

Calcaneal lengthening for planovalgus foot deformity in children with spastic cerebral palsy.

The purpose of this study was to evaluate the effectiveness of calcaneal lengthening in the treatment of planovalgus foot deformity of children with spastic cerebral palsy. Sixteen children (27 feet) with spastic cerebral palsy underwent calcaneal lengthening along with peroneal tendons. The results were assessed clinically and radiographically. Over an average of 3.2 years of follow-up (2.0-5.0), 20 (74.1%) feet showed a satisfactory clinical result, and 21 (77.8%) feet showed a satisfactory radiographic result, according to the modified Mosca's criteria. Dependent ambulators with severe pes planovalgus showed unsatisfactory results compared with independent ambulators with mild to moderate pes planovalgus. These findings suggest that for severe pes planovalgus of children with cerebral palsy, it may be difficult to correct the foot deformity by calcaneal lengthening with peroneal tendons.