Pronation and palmar pinch improve the stability of the medial elbow joint space in high school baseball pitchers.

HYPOTHESIS: We aimed to investigate the contributions of grip, pronation, and pinch to stabilization of the medial elbow joint space; examine their relationship with muscle strength; and assess the effect of stabilization on the medial elbow joint space in baseball pitchers. METHODS: In this controlled laboratory study, we measured the medial elbow joint space using ultrasound during the following conditions: unloading; loading; and loading with grip, pronation, and pinch. To evaluate changes in the medial elbow joint space as a result of various conditions, 1-way repeated-measures analysis of variance and post hoc analysis for multiple comparisons were performed. To investigate whether strong or weak muscle strength improved the medial elbow joint space during the loaded condition, Pearson correlation analysis was performed. Finally, a post hoc power analysis was performed. RESULTS: We enrolled 121 pitchers. The medial elbow joint space in the loaded condition, loaded condition with full grip, and loaded condition with full pinch was significantly larger than that in the unloaded condition. The medial elbow joint space in the loaded condition with full grip, loaded condition with full pronation, and loaded condition with full palmar pinch was significantly smaller than that in the loaded condition. A post hoc power analysis showed that the power of the 1-way repeated-measures analysis of variance was 100%. The strengths of the full grip and palmar pinch were significantly correlated with a reduced gap distance of the medial elbow joint space (P < .001 for both). CONCLUSION: In high school baseball pitchers, pronation and palmar pinch contraction significantly improved the gap distance of the medial elbow joint space in the loaded condition and during grip contraction. Moreover, the grip and palmar pinch strengths were significantly correlated with stabilizing effects on the medial elbow joint space.

Preoperative Nutrition Impacts Retear Rate After Arthroscopic Rotator Cuff Repair.

BACKGROUND: A rotator cuff retear following arthroscopic rotator cuff repair (ARCR) is a concern in older patients. However, only a few of its risk factors are amenable to preoperative intervention. We aimed to elucidate the relationship between preoperative nutritional status and rotator cuff retears after ARCR. METHODS: This single-center retrospective study included patients aged ≥65 years with rotator cuff tears who underwent ARCR. The Geriatric Nutritional Risk Index (GNRI) was used to assess preoperative nutritional status. Data collection encompassed patient demographics, clinical assessments, and surgical specifics. Patients were divided into healed and retear groups based on 2-year post-ARCR magnetic resonance imaging results. Logistic regression analysis was conducted to adjust for confounding factors and detect independent risk factors for retears. The GNRI cutoff value for retear prediction was determined by a stratum-specific likelihood ratio; clinical outcomes were compared based on the cutoff values obtained. RESULTS: Overall, 143 patients were included. The retear rate was 20.3%. The albumin level, GNRI, postoperative shoulder strength of abduction and external rotation, and postoperative Japanese Orthopaedic Association and Constant scores in the retear group were significantly lower than those in the healed group. The logistic regression analysis showed that low risk of morbidity and mortality (compared with no risk) based on the GNRI (odds ratio [OR], 3.39) and medial-lateral tear size per mm (OR = 1.10) were independent risk factors for a retear 2 years after ARCR. Stratum-specific likelihood ratio analysis identified data-driven strata as GNRI < 103, 103 ≤ GNRI < 109, and GNRI ≥ 109. Univariate analysis showed that patients with GNRI < 103 had a significantly higher retear risk than those with 103 ≤ GNRI < 109 and those with GNRI ≥ 109. Logistic regression analysis showed that GNRI < 103 compared with 103 ≤ GNRI < 109 (OR = 3.88) and GNRI < 103 compared with GNRI ≥ 109 (OR = 5.62), along with the medial-lateral tear size per mm (OR = 1.10), were independent risk factors for a retear at 2 years after ARCR. CONCLUSIONS: When assessing the risk of a retear after ARCR, GNRI ≥ 103 may indicate good preoperative nutritional status. However, more data are essential to ascertain the importance of this finding. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Triamcinolone acetonide with arthroscopic capsular release for frozen shoulder promotes early recovery of shoulder abduction.

Background: Current treatment options for frozen shoulder are not established as the standard-of-care. The condition may resolve without intervention, but symptoms may persist despite treatment. Frozen shoulder is associated with inflammatory reactions that can reduce quality of life. Our aim was to determine whether triamcinolone acetonide, an immunosuppressive steroid, improved functional recovery when administered after arthroscopic capsular release (ACR) for frozen shoulder. Methods: We selected participants using inclusion and exclusion criteria designed to reduce the impact of potential confounding factors. Under general anesthesia, we performed ACR followed by manipulation to ensure adequate range of motion (ROM) and wound closure. In the steroid treatment group, we injected triamcinolone acetonide into the glenohumeral joint immediately prior to wound closure. The follow-up period was six months. To determine the efficacy of steroids in improving overall post procedure functional recovery we statistically analyzed data from various qualitative and quantitative variables. Results: Our study consisted of 22 patients with frozen shoulder, 11 in each of the surgery-only and surgery with steroid injection groups. There were no significant differences between groups in the demographic data of the study participants. We observed significantly greater improvements in abduction ROM in the steroid treatment group than in the surgery-only group, at three and six months post treatment. Improvements in other movement parameters were similar in both groups. The steroid-treated group had a significantly higher numerical rating scale score for night pain at three months post treatment than the surgery-only group. Conclusions: Postoperative steroid treatment led to early recovery of the abduction ROM in patients with frozen shoulder. Hence, the current standard-of-care protocol for frozen shoulder and other similar conditions requiring surgical intervention should include this type of treatment. Therapeutic reduction in the inflammatory response following ACR can significantly improve prognosis and quality of life.

The Relationship Between Dynamic Balance Ability and Shoulder Pain in High School Baseball Pitchers.

BACKGROUND: Dynamic balance is essential for pitching motion because pitching kinematics requires whole body coordination. The Star Excursion Balance Test (SEBT) and the Y balance test (YBT) evaluate dynamic balance quantitatively. There are some reports that investigated the relationship between SEBT/YBT and pain in upper and lower extremities, but there is no study among high school baseball pitchers. HYPOTHESIS: Dynamic balance deficiency is associated with shoulder pain among high school baseball pitchers. STUDY DESIGN: Cross-sectional study. LEVEL OF EVIDENCE: Level 4. METHODS: A total of 259 male high school pitchers who participated in the preseason medical checkups were included in the study. YBT was used to measure their dynamic balance. The participants completed a questionnaire which asked if they were currently experiencing shoulder pain. RESULTS: Twenty-two pitchers had shoulder pain during the preseason medical checkups. In the YBT, the posterolateral balance while standing with the axis leg as well as the posteromedial and posterolateral balance while standing with the step leg were significantly lower in the pain group than in the nonpain group (P = 0.05, 0.04, and 0.001, respectively). A logistic regression analysis showed that posterolateral balance when standing with the step leg was an independent risk factor for current shoulder pain (P = 0.04, odds ratio 0.942, 95% CI 0.892-0.996). CONCLUSION: The dynamic balance of high school baseball pitchers with shoulder pain was lower than that of participants without shoulder pain. In particular, posterolateral direction with the step leg standing was significantly related to shoulder pain. CLINICAL RELEVANCE: Among high school baseball pitchers, decreased dynamic balance was related to current shoulder pain. YBT maybe recommended in preseason medical checkups for high school baseball pitchers.

Relationship between upper limb injuries and hip range of motion and strength in high school baseball pitchers.

We aimed to examine the relationship between hip range of motion (ROM) and abduction strength and throwing-related shoulder/elbow injuries in high school baseball pitchers. The study included 135 baseball pitchers. We asked them to fill out a questionnaire at the checkups, that included the dominant arm and the years of baseball experience. To avoid a confirmation bias, the examiners were blinded to the participants' hand dominance. All players underwent physical function measurements, such as height, weight, shoulder and hip strength, and shoulder and hip ROM. Shoulder and elbow injury was defined as shoulder and elbow pain that the patient had been aware of in the past 3 years. The results of injured and non-injured pitchers were compared. Eighty-five pitchers had experienced a shoulder or elbow injury in the past 3 years. The shoulder ROM and strength in the injured and non-injured groups did not differ to a statistically significant extent. The hip external rotation ROM on the dominant side, the hip abduction strength on the non-dominant side, and the hip abduction strength on the dominant side were significantly lower in the injured group than in the non-injured group. The results may contribute to reducing the incidence of these injuries.

Relationship between the Lower Limb Function and Shoulder and Elbow Injuries in Elementary School Baseball Pitchers.

OBJECTIVES: We aimed to examine the relationship between the hip range of motion (ROM) and ankle ROM and throwing-related shoulder and elbow injuries in elementary school baseball pitchers. METHODS: This retrospective comparative study (Level of evidence: Level III) included 195 baseball pitchers (mean age 10.8±1.0 years, range 8-12 years). All pitchers underwent physical function measurements, including height, weight, shoulder strength, and hip and ankle ROM. Shoulder and elbow injury was defined as shoulder and elbow pain that the pitchers had been aware of in the past or at the time of medical checkups. The results for the injured and non-injured groups were then compared. RESULTS: The shoulder ROM and strength in the injured and non-injured groups did not differ to a statistically significant extent. The hip external rotation on the dominant side (injured vs. non-injured: 48.9±11.1° vs. 53.3±9.7°, P<0.01), the hip internal rotation on the non-dominant side (injured vs. non-injured: 36.6±12.0° vs. 40.9±11.0°, P=0.01), and ankle plantar flexion on the non-dominant side (injured vs. non-injured: 52.0±6.8° vs. 54.3±6.7°, P=0.02) were significantly smaller in the injured group than in the non-injured group. CONCLUSIONS: The hip external rotation ROM on the dominant side and the hip internal rotation and ankle plantar flexion on the non-dominant side were significantly lower in the injured group than in the non-injured group. These results may suggest measures to reduce the incidence of elbow and shoulder injuries in elementary school baseball pitchers.

Ankle dorsiflexion deficit in the back leg is a risk factor for shoulder and elbow injuries in young baseball players.

The relationship between ankle joint function and throwing-related injuries has not been demonstrated. We hypothesized that limited ankle joint range of motion (ROM) was related to risk factors for shoulder and elbow injuries in young baseball players. This 12-month prospective cohort study evaluated the age, height, weight, playing position, shoulder, elbow, and ankle function of 228 enrolled baseball players. Shoulder and elbow injuries were tracked during the season. Univariate and multivariate analyses were performed to identify risk factors for shoulder and elbow injuries among participants divided into non-injured and injured groups. Univariate analysis showed that age, height, weight, ROM of elbow flexion in the dominant arm, muscle strength ratio of shoulder abduction, and the likelihood of being a pitcher or a catcher were significantly greater in the injured group than in the non-injured group. ROM of shoulder abduction-external/internal rotation, shoulder total arc on the dominant arm, ankle joint dorsiflexion, and plantar flexion on the back (non-lead) and front (lead) legs were significantly less in the injured group than in the non-injured group. In conclusion, ROM dorsiflexion deficits in the back leg, shoulder abduction-external rotation in the dominant arm, ROM increase in elbow flexion on the dominant side, older age, and being a pitcher were significant independent risk factors for injury.

Risk factor for elbow symptom manifestation in young baseball players with asymptomatic medial elbow abnormalities: a prospective cohort study.

Asymptomatic elbow abnormalities are relatively common in young baseball players, but the factors responsible are unclear. To prospectively identify risk factors related to symptom manifestation in asymptomatic elbow abnormalities, we recruited 573 baseball players (age: 7-14 years) at a pre-participation medical/physical examination in the preseason who were right-handed and had asymptomatic medial elbow abnormalities on ultrasound (US). Baseline preseason and postseason participant characteristics were assessed. A "symptomatic" elbow was defined as an elbow with medial elbow joint problems that prevented ball throwing for ≥ 8 days. After exclusions, 82 players were enrolled, of whom 22 (26.8%) developed a symptomatic elbow. In univariate analyses, the external and internal rotation strengths of the dominant shoulder were significantly greater in the symptomatic group than in the asymptomatic group (P = 0.021). Multivariate logistic regression analysis showed that the internal rotation strength of the dominant shoulder was a significant independent risk factor (odds ratio = 1.091, P = 0.027) for developing a symptomatic elbow. In young asymptomatic baseball players with abnormalities in the medial elbow region of the dominant arm on US, stronger preseason internal rotation strength of the dominant shoulder was a significant independent risk factor for the development of a "symptomatic" elbow.

An analysis of pre-season risk factors for low back injury in high-school baseball pitchers: a prospective study.

Pitching motion requires whole-body coordination; therefore, poor control of the lower extremities, pelvis and trunk may cause shoulder and elbow injuries. However, few studies have described the relationship between the shoulder joint function and low back injury in high-school baseball pitchers. A total of 128 healthy high school pitchers underwent pre-season medical checkups, where their shoulder range of motion and shoulder strength were measured. The participants completed a self-recorded daily questionnaire regarding the presence of low back pain. Pitchers were divided into injured and non-injured groups. Low back injury was observed in 13 participants (13.4%). In the injured group, horizontal adduction on the dominant shoulder was significantly less than in the non-injured group. A logistic regression analysis showed that horizontal adduction on the dominant side was a significant independent risk factor for low back injury during the season. It is important to recognize that restriction of the shoulder function not only causes shoulder and elbow injuries but can also risk low back injury.

Four-year trend in shoulder and elbow injuries in competitive-level high school baseball pitchers: a repeated cross-sectional survey.

BACKGROUND: Shoulder and elbow injuries are the main cause of throwing disability among high school baseball pitchers. However, longitudinal studies on shoulder and elbow injuries among competitive-level high school baseball pitchers have been insufficient. This study aimed to investigate shoulder and elbow injuries in competitive-level high school baseball pitchers over a four-year period and elucidate the effects of implementing medical checkups on the incidence of shoulder and elbow injuries. METHODS: Five hundred fifty-two high school baseball pitchers, who received preseason medical checkups from February 2012 to February 2015, were enrolled in this study. Shoulder and elbow injuries occurring during the season after medical checkups were prospectively evaluated by a postseason questionnaire. Pitchers who were not able to pitch for >7 days owing to shoulder or elbow pain were defined as having shoulder and elbow injuries during the season. The incidence rates of shoulder and elbow injuries during the seasons were calculated and compared over the 4-year period. RESULTS: Ninety-six percent of medical checkup participants were included in the study. The mean questionnaire collection rate of the prospective study was 71.6% (range: 67.7-78.9%). The incidence of shoulder and elbow injuries significantly decreased from 20.0% in 2012 to 7.7% in 2015 (P = .013). CONCLUSION: The four-year trend in the incidence of shoulder and elbow injuries in competitive-level high school baseball pitchers was evaluated. The incidence of shoulder and elbow injuries during the season significantly decreased with a linear downward trend during the survey period after the implementation of medical checkups.

Relationship Between Upper Limb Injuries and Hip Range of Motion in Elementary and Junior High School Baseball Players.

BACKGROUND: Shoulder and elbow injuries are major problems in baseball players. Tightness of the upper extremities has been reported as a risk factor for shoulder and elbow injuries in elementary and junior high school baseball players. However, few studies have been conducted on the relationship between decreased hip range of motion (ROM) and shoulder and elbow injuries. PURPOSE/HYPOTHESIS: This study aimed to prospectively examine the relationship between hip ROM and throwing-related shoulder and elbow injuries in elementary and junior high school baseball players. The hypothesis was that players with unrestricted ROM in the hip would have a reduced risk of upper extremity injuries. METHODS: The study included 263 baseball players (mean ± SD age, 10.5 ± 1.3 years; range, 7-14 years). The following physical parameters were assessed: (1) hip flexion ROM measured in the supine position and (2) hip internal and external rotation in the prone position. After the season, players completed questionnaires regarding shoulder and/or elbow injuries. For comparison, the players were classified as injured (not able to play for ≥8 days because of shoulder and/or elbow problems) or noninjured. RESULTS: During the season, 52 players had shoulder and/or elbow injuries. When the injured and noninjured groups were compared, hip flexion on the dominant side (121.5° ± 12.0° vs 126.7° ± 9.8°, respectively; P < .01), hip flexion on the nondominant side (119.6° ± 11.7° vs 126.0° ± 9.9°, respectively; P < .01), and internal rotation on the dominant side (52.5° ± 11.3° vs 56.8° ± 10.8°, respectively; P = .01) were significantly reduced in the injured group. CONCLUSION: We identified preseason decreases in flexion bilaterally and internal rotation on the dominant side as risk factors for shoulder and elbow injuries in elementary and junior high school baseball players. Further studies are required to prevent disabilities in elementary and junior high school baseball players through development of prevention and intervention programs.