A Field-expedient Arm Care Screening Tool Can Identify Musculoskeletal Risk Factors in Baseball Players.

BACKGROUND: Preseason movement screening can identify modifiable risk factors, deterioration of function, and potential for injury in baseball players. Limited resources and time prevent high school baseball coaches from performing movement screens on their players. HYPOTHESIS: The arm care screen (ACS) will be highly sensitive to detecting musculoskeletal risk factors. STUDY DESIGN: Cross-sectional. LEVEL OF EVIDENCE: Level 3. METHODS: A total of 150 baseball players were independently scored on the ACS electronically by reviewing a video recording of each player's screening performance. Discriminability of the ACS was determined with a 2 × 2 contingency table dichotomizing musculoskeletal risk factors as present or absent based on a predetermined cutoff value and those who passed or failed the corresponding ACS subtest. RESULTS: High sensitivity was observed on the reciprocal shoulder mobility (0.89; 95% CI 0.81-0.94), 90/90 total body rotation (0.86; 95% CI 0.79-0.92), and lower body diagonal reach (0.85; 95% CI 0.78-0.91) tests of the ACS suggesting sufficient ability to identify musculoskeletal impairments and risk factors. CONCLUSION: The ACS is a simplistic screening tool that the coach can administer to discriminate between youth, high school, and college-level baseball players who possess musculoskeletal risk factors. The ACS subtests demonstrated high sensitivity for correctly identifying musculoskeletal risk factors common in baseball players and can be useful as a screening tool for baseball coaches developing arm care exercise programs. CLINICAL RELEVANCE: A field-expedient screen could provide coaches the ability to identify musculoskeletal risk factors that need to be addressed to minimize injury risk factors in a time-efficient manner.

Comparison of manual therapy techniques on ankle dorsiflexion range of motion and dynamic single leg balance in collegiate athletes.

INTRODUCTION/PURPOSE: Literature consistently identifies two key examination components when managing ankle/foot pathologies: 1) dorsiflexion range of motion (DFROM) and 2) single limb balance. Mobilizations with movement (MWM) and Instrument-Assisted Soft Tissue (IASTM) are two emerging manual therapy (MT) options in the management of ankle/foot conditions. METHODOLOGY/SAMPLE: In this observational cohort study, 147 subjects were randomized in a block fashion as follows: 1) Control, 2) IASTM, 3) MWM, and 4) Combination of both MT interventions. Descriptive statistics of the sample were conducted with integrity checks followed by comparative analysis for mean change between the variables or DFROM and YBTLQ ™ performance. RESULTS: ANOVA Welch's F indicated significant differences between the treatment conditions (Welch's F (3,75.669) = 4.533, p = .006). Games-Howell post hoc tests indicated significantly more change in DFROM in the IASTM (p = .043) and CKCMOB (p = .026) conditions when they were administered as single treatments, than in the Control Condition or when the treatments were combined. Dynamic balance, as measured by the YBT-LQ™, did not yield a significant response based on the intervention arm. DISCUSSION/CLINICAL RELEVANCE: Specifically, IASTM or closed kinetic chain (CKC) MWM MT techniques used in isolation can be considered a cost-effective intervention that can be administered by a skilled MT practitioner in a "low risk-high reward" clinical scenario with potential biomechanical and neurophysiological benefits for improving CKCDFROM.

The Intra- and Inter-rater Reliability of an Arm Care Screening Tool in High School Baseball Coaches.

BACKGROUND: Preseason movement screening can identify modifiable risk factors, deterioration of function, and potential for injury in baseball players. Limited resources and time intensive testing procedures prevent high school coaches from accurately performing frequent movement screens on their players. PURPOSE: To establish the intra-rater and inter-rater reliability of a novel arm care screening tool based on the concepts of the Functional Movement Screen (FMS™) and Selective Functional Movement Assessment (SFMA™) in high school coaches. STUDY DESIGN: Methodological intra- and inter-rater reliability study. METHODS: Thirty-one male high school baseball players (15.9 years ± 1.06) were independently scored on the Arm Care Screen (ACS) by three examiners (two coaches, one physical therapist) in real-time and again seven days later by reviewing video recordings of each players' initial screening performance. Results from each examiner were compared within and between raters using Cohen's kappa and percent absolute agreement. RESULTS: Substantial to excellent intra-rater and inter-rater reliability were established among all raters for each component of the ACS. The mean Cohen's kappa coefficient for intra-rater reliability was 0.76 (95% confidence interval, 0.54-0.95) and percent absolute agreement ranged from 0.82-0.94 among all raters. Inter-rater reliability demonstrated a mean Cohen's kappa value of 0.89 (95% confidence interval, 0.77-0.99) while percent absolute agreement between raters ranged from 0.81-1.00. Intra- and inter-rater reliability did not differ between raters with various movement screening experience (p>0.05). CONCLUSIONS: High school baseball coaches with limited experience screening movement can reliably score all three components of the ACS in less than three minutes with minimal training. LEVEL OF EVIDENCE: Level 3, Reliability study.

Current Concepts in Arm Care Exercise Programs and Injury Risk Reduction in Adolescent Baseball Players: A Clinical Review.

CONTEXT: Awareness of important injury risk factors associated with excessive pitching volume has been highlighted in the literature, but injury rates remain high. Shoulder pain in baseball players is associated with various changes in musculoskeletal movements, which presents as measurable impairments throughout the kinetic chain. Baseball coaches and rehabilitation professionals have utilized exercise programs targeting strength and flexibility of the throwing arm to prevent injuries. The purpose of this review is to summarize the current evidence regarding the effectiveness of arm care exercise programs in reducing upper extremity injury rates in adolescent baseball players. EVIDENCE ACQUISITION: A search of electronic databases, including CINAHL with full text, MEDLINE, and SPORTDiscus was conducted to retrieve available articles in English from the years 2010 through 2020. The search terms injury prevention, exercise, and adolescent baseball were used. STUDY DESIGN: Clinical review. LEVEL OF EVIDENCE: Level 4. RESULTS: Improving shoulder internal rotation range of motion by stretching the posterior shoulder muscles daily was associated with a 36% risk reduction of shoulder and elbow injuries. Group-based arm care exercise programs that target multiple musculoskeletal impairments demonstrated an approximately 50% reduced risk of elbow injury. CONCLUSION: For adolescent baseball players, arm care injury prevention programs focusing on important musculoskeletal impairments are effective at reducing injury incidence rates. Multimodal injury prevention programs that improve multiple musculoskeletal impairments are more comprehensive and may result in better injury reduction than programs focusing on a singular impairment.

Differences in PlayerLoad and pitch type in collegiate baseball players.

PlayerLoad is derived from a tri-axial accelerometer device and is a measure of an athlete's external training load. Tri-axial accelerometers (Optimeye S5, Catapult Sports, Melbourne, Australia) were worn by 25 collegiate pitchers during a pitching session. Pitches included fastballs, curve balls, sliders, and changeups. Peak and sum PlayerLoad were calculated for fastballs, curve balls, sliders, and changeups. Statistical analysis included paired t-tests (p < 0.01) and effect size indexes (ESI). Peak and sum PlayerLoad were higher for fastballs compared to changeups (N = 20; ESIpeak = 0.47, p= 0.001 and ESISum = 0.13, p = 0.001, respectively). Peak and sum PlayerLoad were not different comparing fastball to curveball (N = 12; ESIpeak = 0.24, p = 0.050 and ESISum<0.01, p = 0.106) and fastball to slider (N = 12; ESIpeak = 0.32, p = 0.088 and ESISum = 0.02, p = 0.221). Fastball velocity (37.1 ± 2.1 m/s) differed from the changeup (33.8 ± 1.9 m/s; p < 0.001), curveball (32.2 ± 1.2; p < 0.001), and slider (33.8 ± 1.3 m/s; p < 0.001). Pitching workload may differ based on pitch type. Pitch counts may not capture true player fatigue due to variability in stresses resulting from different pitch types.

Baseball pitching biomechanics in relation to pain, injury, and surgery: A systematic review.

OBJECTIVES: To investigate the relationship between baseball pitching biomechanics and pain, injury, or surgery, in pitchers of all ages and competition levels. DESIGN: Systematic review. METHODS: This study was registered on Prospero (CRD42019137462). Four online databases (MEDLINE, SPORTDiscus, CINAHL, and Embase) from inception to June 13, 2019 were systematically searched. Risk of bias was assessed through the modified Downs and Black. RESULTS: 967 titles/abstracts were screened with 11 studies (1376 pitchers) included. Four studies used 3D biomechanical analyses, five studies video analysis, and two studies evaluated EMG activity. Level 1b evidence suggests that injured pitchers had greater elbow valgus torque at late arm cocking (injured: 91.6Nm, non-injured: 74.7Nm, p=0.013) and early trunk rotation was predictive of increased upper extremity surgical risk (Hazard Ratio: 1.69 (95% CI 1.02-2.80)). Level 3b evidence observed pitchers with upper extremity surgical history had greater lateral trunk tilt at release (surgery: 29.3°, controls: 23.4°, p=0.035), and flexor carpi ulnaris EMG activity was decreased (injured: 68% MMT, controls: 103% MMT) in pitchers with elbow injury. CONCLUSIONS: Increased elbow valgus torque and early trunk rotation were injury risk factors, and elbow injured pitchers displayed diminished forearm muscle activity. Due to the low power of many of these studies, and the lack of prospective 3D biomechanical studies, other pitching biomechanical variables cannot be ascertained as injury risk factors. Future studies are needed to prospectively assess pitching injury risk through 3D biomechanical methods.

Clinical examination factors that predict delayed recovery in individuals with concussion.

BACKGROUND: Risk factors for prolonged recovery after concussion have been well researched, but specific objective clinical examination findings have not. This study examined whether clinical examination results could predict delayed recovery (DR) in individuals with concussion diagnosis. A secondary aim explored the influence of early examination on individual prognosis. METHODS: The study was a retrospective, observational cohort design that included 163 individuals seen at a concussion clinic who were followed longitudinally until cleared for sports activity. Cognitive, visual, balance, vestibular, and cervical clinical testing and symptom assessment were performed at initial evaluation. DR was calculated by taking the median value associated with time to clearance for activity. Bivariate logistic regression analysis was calculated to determine odds ratios (and 95% confidence intervals) for the odds of DR with presence or absence of each clinical finding. Multivariate analyses were used to define the best predictors of DR. RESULTS: 80 of 163 individuals were considered delayed in their clearance to activity. Cognitive impairments (OR = 2.72; 95%CI = 1.40, 5.28), visual exam findings (OR = 2.98; 95%CI = 1.31, 6.80), and vestibular exam findings (OR = 4.28; 95%CI = 2.18, 8.43) all increased the odds of a DR. Multivariate modeling retained cognitive symptoms and clinical examination-vestibular testing as predictors of delayed recovery. Time to examination after injury was a mediator for DR. CONCLUSIONS: The clinical examination provides value in identifying individuals who are likely to exhibit a delayed clearance. In particular, vestibular impairments identified clinically at initial evaluation and cognitive symptoms were associated with increased odds of a DR to return to activity. Our data support that early implementation of a standardized clinical examination can help to identify individuals who may be more at risk of prolonged recovery from concussion.

Identification of Risk Factors Prospectively Associated With Musculoskeletal Injury in a Warrior Athlete Population.

BACKGROUND: Musculoskeletal injuries are a primary source of disability. Understanding how risk factors predict injury is necessary to individualize and enhance injury reduction programs. HYPOTHESIS: Because of the multifactorial nature of musculoskeletal injuries, multiple risk factors will provide a useful method of categorizing warrior athletes based on injury risk. STUDY DESIGN: Prospective observational cohort study. LEVEL OF EVIDENCE: Level 2. METHODS: Baseline data were collected on 922 US Army soldiers/warrior athletes (mean age, 24.7 ± 5.2 years; mean body mass index, 26.8 ± 3.4 kg/m2) using surveys and physical measures. Injury occurrence and health care utilization were collected for 1 year. Variables were compared in healthy versus injured participants using independent t tests or chi-square analysis. Significantly different factors between each group were entered into a logistic regression equation. Receiver operating characteristic curve and accuracy statistics were calculated for regression variables. RESULTS: Of the 922 warrior athletes, 38.8% suffered a time-loss injury (TLI). Overall, 35 variables had a significant relationship with TLIs. The logistic regression equation, consisting of 11 variables of interest, was significant (adjusted R2 = 0.21; odds ratio, 5.7 [95% CI, 4.1-7.9]; relative risk, 2.5 [95% CI, 2.1-2.9]; area under the curve, 0.73). Individuals with 2 variables had a sensitivity of 0.89, those with 7 or more variables had a specificity of 0.94. CONCLUSION: The sum of individual risk factors (prior injury, prior work restrictions, lower perceived recovery from injury, asymmetrical ankle dorsiflexion, decreased or asymmetrical performance on the Lower and Upper Quarter Y-Balance test, pain with movement, slower 2-mile run times, age, and sex) produced a highly sensitive and specific multivariate model for TLI in military servicemembers. CLINICAL RELEVANCE: A better understanding of characteristics associated with future injury risk can provide a foundation for prevention programs designed to reduce medical costs and time lost.

Effects of a corrective heel lift with an orthopaedic walking boot on joint mechanics and symmetry during gait.

BACKGROUND: Orthopaedic walking boots are commonly prescribed following injury and surgery. The boot creates a leg length discrepancy which is thought to affect limb symmetry and gait mechanics. This study aimed to examine the effects of a corrective heel lift for the contralateral limb on the mechanics and symmetry of walking with an orthopaedic walking boot. RESEARCH QUESTION: Does a corrective heel lift reduce biomechanical alterations and asymmetries caused by an orthopaedic boot during gait? METHODS: Healthy males (n=17) walked with normal shoes (Shod), an orthopaedic boot (Boot), and a corrective heel lift on the contralateral limb to the boot (Lift). A 10-camera motion capture system (Vicon, 100Hz) and four force platforms (AMTI, 1000 Hz) recorded lower extremity biomechanics. Pairwise statistics tested for differences in hip and knee kinematics and kinetics, and a symmetry index quantified limb symmetry. FINDINGS: The Boot affected the sagittal and frontal plane hip mechanics and transverse plane knee mechanics (p<0.05), and increased the asymmetry compared to the Shod condition. The Lift improved the symmetry of some measures but increased the frontal plane hip asymmetry compared to the Boot. However, introducing the Lift did not change all kinematic variables affected by the boot. SIGNIFICANCE: The Lift reduced some of the asymmetries introduced by the Boot, but also introduced new asymmetry in the hip frontal plane motion. The leg length discrepancy caused by the boot is probably not the only cause of altered gait mechanics. Prescribing a heel lift to a patient with an orthopaedic walking boot should be based on the individual patient's needs.

THE RELATIONSHIP BETWEEN TRUNK ROTATION, UPPER QUARTER DYNAMIC STABILITY, AND THE KERLAN-JOBE ORTHOPAEDIC CLINIC OVERHEAD ATHLETE SHOULDER AND ELBOW SCORE IN DIVISION I COLLEGIATE PITCHERS.

HYPOTHESIS/PURPOSE: The purpose of this study was to assess relationships between active trunk rotation range of motion (TROM), upper quarter dynamic stability, and composite and individual item KJOC scores in collegiate baseball pitchers. A secondary purpose was to determine whether differences exist between baseball pitchers with and without an injury history in terms of their performance on TROM, upper quarter dynamic stability, and composite and individual KJOC scores. It was hypothesized that increased TROM and upper quarter dynamic stability are associated with better (higher) KJOC scores and pitchers with an injury history would exhibit lower KJOC scores compared to uninjured pitchers. STUDY DESIGN: Cross-sectional Cohort Study. METHODS: Thirty-six college pitchers were assessed for TROM, performance on the Upper Quarter Y-Balance Test (YBT-UQ) and they also completed the KJOC. Subjects were grouped based on previous injury history: injured, required surgery, (IS, n=9), injured, no surgery, (INS, n=6), and uninjured (UI, n=21). Pearson's Correlations were used to assess relationships between clinical measurements and the KJOC. One-way ANOVAs were used to assess differences in TROM, YBT-UQ, and KJOC scores between groups (P<0.05). RESULTS: No significant relationships were detected between TROM measures and KJOC composite scores (throwing arm: r = .239, p = 0.16; non-throwing arm: r=.291, p = 0.09). A moderate relationship was found between the YBT-UQ and the KJOC scores (throwing arm: r = .413, p = 0.01; non-throwing arm: r=.380, p = 0.02). The mean KJOC scores for item 1 (warm-up limitations) were significantly different between all three groups (IS: 6.7, INS: 9.7, UI: 9.1; p = 0.015). Mean scores on item 5 (strain on relationships with coaches) and item 8 (limitations in competition endurance) were significantly different between the IS and UI groups (Item 5 = IS: 7.8, UI: 9.5, p = 0.02; Item 8=IS: 6.4, UI: 8.8, p = 0.04). CONCLUSION: A positive moderate association was found between upper quarter dynamic stability as measured by the YBT-UQ and the KJOC. Pitchers with no surgical history had better KJOC scores for warm up time, competitive endurance, and impact on team relationships. LEVEL OF EVIDENCE: 3.

RELATIONSHIP BETWEEN THE LOWER QUARTER Y-BALANCE TEST SCORES AND ISOKINETIC STRENGTH TESTING IN PATIENTS STATUS POST ACL RECONSTRUCTION.

BACKGROUND: ACL injuries are common among sports populations and achieving adequate lower extremity strength is important prior to return to play. Access to isokinetic testing equipment that measures lower extremity strength is limited. Screening tools that measure functional criteria are accessible to clinicians, however the tools' relationship to strength constructs have not been investigated in an ACL reconstructed (ACLR) population. PURPOSE: The primary objective was to determine if relationships exist between isokinetic peak knee extension torque (PKET), peak knee flexion torque (PKFT), hamstring to quadriceps (HQ) ratios, and YBT-LQ performance following ACLR. The secondary objective was to observe differences in isokinetic strength ability between high and low performers on the YBT-LQ. STUDY DESIGN: Retrospective Chart Review. METHODS: Medical records of forty-five ACL-reconstructed subjects, between five-12 months post-surgery were queried for functional assessment data collected during the institution's standard outcome testing battery. Variables of interest included: demographic and anthropomorphic measures, YBT-LQ performance, and involved limb isokinetic PKET, PKFT, and HQ ratios. Performance on each measure, as well as asymmetry between sides, was analyzed using a correlation matrix. RESULTS: Statistically significant (p<0.01) relationships were identified between YBT-LQ anterior reach asymmetry and the PKET deficit (r=0.264). PKET and PKFT on the involved limb correlated to performance of anterior reach (r=0.591, p<0.01)(r=0.493, p<0.01), posteromedial reach (r=0.498, p<0.01)(r=0.577, p<0.01), and posterolateral reach (r=0.294, p<0.05)(r=0.445, p<0.01) respectively. Similar relationships existed on the uninvolved side, but to a lesser extent. High and low performers on the YBT-LQ demonstrated lower and higher extension torque deficits, respectively. CONCLUSION: While each test measures unique constructs, there are associations between components of the tests. In the ACLR population, both the YBT-LQ and isokinetic strength testing can expose asymmetries and impact return to play decision making. LEVEL OF EVIDENCE: 2b.

Incidence of Musculoskeletal Injury in US Army Unit Types: A Prospective Cohort Study.

BACKGROUND: Musculoskeletal injuries during military service are a primary source of disability, resulting in 2.4 million annual health care visits and 25 million limited-duty days. While the injury incidence during basic training is well documented, there is little understanding of injury distribution by organization type in the US Army following initial training. OBJECTIVE: To compare injury incidence, distribution, and impact across various military units. METHODS: In this prospective observational cohort study, comprehensive injury data from subject questionnaires and medical chart reviews were collected over 12 months for 1430 initially healthy Army personnel, representing combat, combat support, combat service support, and ranger units. Health care utilization and time loss due to injury were also collected. RESULTS: Of 1430 soldiers, 481 (33.6%) had time-loss injury, 222 (15.5%) were injured without limited work, 60 (4.2%) reported an injury but did not seek medical care, and 667 (46.6%) were uninjured. Across the whole sample, injuries were responsible for 5.9 ±14.4 medical visits per soldier, 21 902 days of limited work, and $1 337 000 ($1901 ± $6535 per soldier) in medical costs. Considering only those reporting injury, each person averaged 36.3 ± 59.7 limited-work days. The injury incidence was highest in combat service support units (65.6%), with a risk ratio 1.60 times that of the reference group (combat, 41.1%). CONCLUSION: Combat support and combat service support personnel were more likely to have 1 or more injuries compared to rangers and combat personnel. The higher relative risk of injury in support units should be explored further. J Orthop Sports Phys Ther 2018;48(10):749-757. Epub 22 May 2018. doi:10.2519/jospt.2018.7979.

The Relationship Between Trunk Rotation, Upper Quarter Dynamic Stability, and Pitch Velocity.

Bullock, GS, Schmitt, AC, Chasse, PM, Little, BA, Diehl, LH, and Butler, RJ. The relationship between trunk rotation, upper quarter dynamic stability, and pitch velocity. J Strength Cond Res 32(1): 261-266, 2018-Understanding the relationship between upper quarter mobility, dynamic stability, and pitching velocity may be beneficial in elucidating underlying factors that affect pitching performance. The purpose of this study was to investigate upper trunk rotation mobility and upper quarter dynamic stability and their correlation to pitch velocity in NCAA Division I collegiate pitchers. We hypothesized that collegiate pitchers with greater upper trunk rotation mobility and upper extremity dynamic stability would exhibit higher pitching velocity. Trunk rotation and the Upper Quarter Y-Balance Test (YBT-UQ) were measured using standardized protocols. Collegiate pitchers (N = 30) then proceeded to complete their team prescribed dynamic and throwing warm-up followed by a pitching session from regulation distance at 100% effort. Each pitch was recorded for velocity and pitch type, only fastballs were used in analysis. The relationships between trunk rotation and fastball velocity, and YBT-UQ scores and fastball velocity were assessed using a series of 2-tail Pearson's correlations (p < 0.05). Throwing and nonthrowing sides (69.6 ± 9.5°, 70.7 ± 9.4°) had similar trunk rotation mobility. No statistically significant correlation between upper trunk rotation mobility and pitch velocity was found (throwing arm: r = 0.131; p < 0.491; nonthrowing arm: r = 0.135; p < 0.478). There was also no correlation between the YBT-UQ and fastball velocity. In this study of Division I baseball pitchers, we found no relationship between trunk rotational mobility, upper quarter dynamic stability, and pitching velocity. This suggests that increased upper extremity stability and trunk mobility are not directly related to fastball velocity. Understanding factors that associate to velocity may be helpful in predicting pitching performance.

Basketball Players' Dynamic Performance Across Competition Levels.

Bullock, GS, Arnold, TW, Plisky, PJ, and Butler, RJ. Basketball players' dynamic performance across competition levels. J Strength Cond Res 32(12): 3537-3542, 2018-Dynamic balance is an integral component in screening lower extremity injury risk. Previous research has identified the need to create sport- and competition level-specific dynamic balance injury cut points. The purpose of this study was to determine if dynamic balance differences exist, using the Lower Quarter Y Balance Test (YBT-LQ), across varying competition levels (middle school, high school, college, and professional), in basketball players. Subjects were participating at the middle school (MS; n = 88), high school (HS; n = 105), college (COL; n = 46), and professional levels (PRO; n = 41). Statistical analysis was completed with a series of analysis of variance tests. Tukey post hoc tests were used to identify specific group-to-group differences if statistical significance (p ≤ 0.05) was observed. Effect size indices (ESI) were also calculated to provide an estimate of the clinical relevance. In the anterior reach, HS basketball players performed statistically better than the MS and COL (p < 0.01, ESI = 0.58) athletes, and all these groups performed better than the PRO basketball players (p < 0.01, ESI = 1.72). For the posteromedial, posterolateral reach directions and the composite score, the HS, COL, and PRO basketball players were not significantly different from each other; however, the HS group did reach further than the MS group (p < 0.01-0.02, ESI = 0.40-0.55). The PRO basketball players exhibited a lower asymmetrical total score compared with MS, HS, and COL players (p < 0.01-0.02, ESI = 0.52-0.68). Different competition levels displayed varying dynamic balance strategies. Creating basketball competition levels normative values for dynamic balance could help define injury risk cut points.

Examining Differences in Movement Competency in Professional Baseball Players Born in the United States and Dominican Republic.

CONTEXT: Dominican Republic (DR) players have different training norms, which can affect their resiliency and performance. The variance among DR players' training regimens may be influenced by the degree of training incorporating fundamental movement patterns. OBJECTIVE: To examine differences in fundamental movement patterns in United States (US)-born versus DR-born professional baseball players. DESIGN: Cross-sectional cohort. SETTING: Professional baseball athletic training room. PARTICIPANTS: One hundred forty-two players (76 DR-born and 66 US-born) who were recently selected by a Major League Baseball team. INTERVENTION: Subjects completed the Functional Movement Screen using the standardized 7 movement tests and the 3 isolated clearing tests. MAIN OUTCOME MEASURES: The primary variables studied were composite score, left and right asymmetry, and individual movement standard scores. Two-way chi-squared analysis was utilized for the statistical analysis with statistical significance being identified at P < .05. RESULTS: DR players had a larger number of 1s (7.8% vs 3.0%) and 3s (10.5% vs 1.5%) on the right-sided hurdle step and a greater percentage of 3s (82.8% vs 60.6%) on right-sided shoulder mobility. US players had a larger percentage of 3s (33.3% vs 13.4%) and a lower percentage of 1s (2.2% vs 15.1%) on the active straight leg raise and a greater percentage of passable scores (≥2; 99.5% vs 65.8%) on the trunk stability push-up. CONCLUSION: This study suggests that fundamental movement competency differs between US- and DR-born professional baseball players. Based on these movement competency differences, a player's country of origin may be taken into account to create an effective training program.

The validity and reliability of ultrasound on identifying supraspinatus tears during passive external rotation from 0° to 30°: a pilot project.

BACKGROUND: Controversy exists regarding how much external rotation should be allowed following rotator cuff repair. Clinicians may use ultrasound imaging (USI) to visualize the supraspinatus (SSp) tendon during passive external rotation. However, the validity and reliability of USI used to assess supraspinatus tendon gap formation during external rotation needs to be established prior to using this technique in patient cohorts. METHODS: Ten subjects with magnetic resonance imaging (MRI) confirmation of full-thickness SSp tears were matched to 10 control subjects. Images of the SSp were obtained at 0°, 10°, 20° and 30° of external rotation by a blinded tester on two occasions to establish both validity and reliability of the measure. RESULTS: Validity was established as 70% agreement between the USI and MRI confirmed SSp tear group; reliability was established at greater than 0.90 at all positions of external rotation measured. CONCLUSIONS: USI may be used to detect SSp tears with 70% validity, and the technique is reliable in all positions of external rotation.

KINEMATIC AND KINETIC VARIABLES DIFFER BETWEEN KETTLEBELL SWING STYLES.

BACKGROUND: Kettlebell (KB) and indian club swings (ICS) are used diversely for developing strength and power. It has been proposed that multiple swing techniques can be used interchangeably to elicit similar adaptations within performance training. Hypothesis/Purpose: It was hypothesized that there will be not be a difference in peak joint angles between types of swings. Furthermore, given the nature of the overhead kettlebell swing (OKS), it was hypothesized that the OKS will be associated with a greater cycle time and a greater vertical impulse compared to shoulder height swing (SKS) and ICS. The purpose of this study was to analyze the kinematics and kinetics of the SKS, OKS, and ICS. STUDY DESIGN: Cross-sectional cohort. METHODS: Fifteen healthy subjects underwent 3D biomechanical analysis for assessment of kinematic and kinetic data. Subjects performed two trials of ten repetitions at full effort for each swing in a randomized order using either a standard set of 0.45 kg indian clubs or sex specific KB loads (Female = 12kg, Male = 20kg). Lower extremity sagittal plane kinematics and kinetics were analyzed for peak values during the down and up portions of the swing patterns. Statistical analyses were carried out utilizing one-way ANOVAs (p<.05) and effect size indices. RESULTS: Cycle time for the OKS was 34% longer than the SKS and ICS (p<.001; ESISKS = 2.09, ESIICS=1.92). In general, ankle (SKS: 0.82 ± 0.16; OKS: 0.90 ± 0.21; ICS: 0.60 ± 0.15 BW*BH) and hip joint moments (SKS: 2.34 ± 0.68; OKS: 2.32 ± 0.53; ICS: 1.84 ± 0.47 BW*BH) and joint powers, along with peak vertical ground reaction forces (vGRF) (SKS: 0.98 ± 0.14; OKS: 0.96 ± 0.10; ICS: 0.86 ± 0.11 BW/s), were higher in the SKS and OKS than the ICS (p<.001; ankle: ESISKS/OKS=0.43, ESISKS/ICS=1.42; hip: ESISKS/OKS=0.03, ESISKS/ICS=0.87; vGRF: ESISKS/OKS=1.80, ESISKS/ICS=0.20). There were no observed differences found in peak joint angles between the movements. CONCLUSION: Although these swings are kinematically similar, the differing kinetic demands of these exercises may be important in selecting the right training modality for specific strength and power training. LEVEL OF EVIDENCE: 2.

Examining Fundamental Movement Competency and Closed-Chain Upper-Extremity Dynamic Balance in Swimmers.

Abnormal fundamental movement patterns and upper-quarter dynamic balance are proposed mechanisms affecting athletic performance and injury risk. There are few studies investigating functional movement and closed-chain upper-extremity dynamic stability in swimmers. The purpose of this study was to determine differences in fundamental movement competency and closed-chain upper-extremity dynamic balance, using the Functional Movement Screen (FMS) and Upper-Quarter Y Balance Test (YBT-UQ), of high school (HS; n = 70) and collegiate (COL; n = 70) swimmers. Variables included the individual movement tests on the FMS and the average normalized reach (percent limb length [%LL]) for each direction, with the YBT-UQ. Statistical analysis was completed using a chi square for the independent test scores on the FMS while independent samples t-test to examine performance on the YBT-UQ (p ≤ 0.05). HS swimmers exhibited a statistically significant greater percentage of below average performance (score of 0 or 1) on the following FMS tests: lunge (HS: 22.9%, COL: 4.3%), hurdle step (HS: 31.4%, COL: 7.1%), and push-up (HS: 61.4%, COL: 31.4%). Furthermore, COL males performed worse in the lunge (male: 9%, female: 0%), whereas COL females had poorer efficiency in the push-up (male: 17.6%, female: 44%). Significant effects of competition level and sex were observed in YBT-UQ medial reach (HS: female 92.06, male 101.63; COL: female 101.3, male 101.5% LL). Individual fundamental movement patterns that involved lumbopelvic neuromuscular control differed between HS and COL swimmers. General upper-extremity dynamic balance differed between competition levels. These data may be helpful in understanding injury and performance-based normative data for participation and return to swimming.

Difference in Functional Performance on the Upper-Quarter Y-Balance Test Between High School Baseball Players and Wrestlers.

CONTEXT: The Upper Quarter Y-Balance Test (YBT-UQ) is a unique movement test where individuals perform at the limits of their stability, requiring the coordination of balance, proprioception, range of motion, and stabilization. It is not yet clear if performance on the YBT-UQ differs between sports with dissimilar emphasis on upper-extremity performance. OBJECTIVE: To compare performance on the YBT-UQ between wrestlers, whose sport requires some degree of closed-chain activity, and baseball players, whose sport is primarily open kinetic chain in nature. DESIGN: Cross-sectional. SETTING: High school preparticipation physical assessment. PARTICIPANTS: 24 healthy high school male wrestlers (mean age 16.12 ± 1.24 y) and 24 healthy high school male baseball players (mean age 15.79 ± 1.25 y). INTERVENTIONS: All subjects performed the YBT-UQ, which requires reaching in 3 directions while maintaining a push-up position. MAIN OUTCOME MEASURES: The variables of interest include the maximum reach in each direction, as well as the composite score. In addition, asymmetries between limbs for each reach direction were compared. RESULTS: Wrestlers performed significantly better than baseball players in the medial direction, inferolateral direction, and in composite scores. In the medial direction, wrestlers exhibited greater scores (P < .01) on both left and right limbs, 10.5 ± 10.2%LL and 9.95 ± 10.2%LL, respectively. Significant differences (P < .01) were also observed in the inferolateral direction, with a difference of 11.3 ± 12.0%LL on the left and 8.7 ± 11.0%LL on the right. Composite scores were higher (P < .01) for the wrestlers, with a difference of 7.0% on the left and 7.1% on the right. CONCLUSIONS: This study suggests that wrestlers perform better on the YBT-UQ than baseball players. The findings may suggest sport-specific normative data for the YBT-UQ in high school athletes.

Competition-Level Differences on the Lower Quarter Y-Balance Test in Baseball Players.

CONTEXT: Decreased performance in dynamic balance has previously been associated with a history of ulnar collateral ligament injury in baseball players. Previous research on dynamic balance in soccer players has shown that test performance depends on competition level. However, dynamic balance has yet to be examined in baseball players. OBJECTIVE: To understand normative values and determine differences in dynamic balance, as measured by the Lower Quarter Y-Balance Test, across competition levels in baseball players. DESIGN: Cross-sectional study. SETTING: Preseason physical examinations. PATIENTS OR OTHER PARTICIPANTS: Dynamic balance was measured in 88 high school (HS), 78 collegiate (COL), and 90 professional (PRO) baseball players. MAIN OUTCOME MEASURE(S): All participants completed the Lower Quarter Y-Balance Test using the standard protocol. In unilateral stance, they reached with 1 foot in the anterior, posteromedial, and posterolateral directions. We calculated 1-way analyses of variance to compare performance, composite score, and reach asymmetry for each direction as well as the sum of the asymmetry values (P < .05). Composite score was calculated by averaging the maximum normalized reach scores. Reach asymmetry was determined by calculating bilateral differences in reach ability. RESULTS: In comparison with the HS and COL groups, the PRO players exhibited greater posteromedial (P < .01; effect size index [ESI]HS = 1.06, ESICOL = 0.95) and posterolateral reach (P < .01; ESIHS = 0.82, ESICOL = 0.84) as well as a greater composite score (P < .01; ESIHS = 0.60, ESICOL = 0.87). In contrast, HS baseball players exhibited increased anterior reach (P < .01; ESICOL = 0.60, ESIPRO = 0.39) compared with the COL and PRO cohorts. No significant differences in reach asymmetry were observed among groups. CONCLUSIONS: Lower extremity dynamic balance performance differed based on the baseball players' competition level. These baseline data may be helpful in identifying low-performing athletes who might benefit from neuromuscular interventions.