Measuring the Average Peak Timing of Kinematic Variables in Youth and Adolescent Baseball Pitchers.

Background: Previous studies have examined the timing of peak kinematic variables during the pitching cycle in high school, collegiate, and professional pitchers. These same variables have been studied less in younger populations. Purpose: To determine whether youth and adolescent baseball pitchers will experience peaks in certain kinematic variables at different times throughout the pitching cycle compared to professional/collegiate pitchers. Study Design: Cross-sectional, descriptive study. Methods: Twenty-four participants were recruited for testing consisting of five recorded pitches using 3-Dimensional VICON® motion analysis system. The maximum values and timing of the peak kinematic variables were averaged across all trials using VICON Polygon® data analysis software. These values were recorded as percentages of the pitching cycle, defined from foot contact (0%) to ball release (100%). The following variables were examined: shoulder external rotation range of motion, shoulder internal rotation velocity, trunk rotation range of motion, trunk rotation velocity, pelvic rotation velocity, and stride length. Descriptive outcomes were calculated and results were compared to previous studies examining the same variables in collegiate and professional pitchers. Results: Twenty-four male participants (mean age 12.75 years, SD ± 2.02) were included in the study. Mean and standard deviations were identified for peak kinematic variables of shoulder external rotation ROM (158.71°, ±9.32), shoulder internal rotation velocity (92.26 rad/sec, ±19.29), trunk rotation velocity (15.94 rad/sec, ±1.68), trunk rotation ROM (23.57°, ±8.14), and average stride length (81.97% height ±4.57). Additionally, mean and standard deviations of peak kinematic variables were expressed as percentages to reflect when they occurred in the pitching cycle and included trunk rotation ROM (8.45%, ±12.72), pelvic rotation velocity (33.26%, ±16.42), trunk rotation velocity (41.59%, ±9.27), shoulder external rotation ROM (71.34%, ±6.61), and shoulder internal rotation velocity (86.93%, ±6.45). Conclusion: The sequential order of each variable was similar in youth and adolescents in comparison to collegiate and professional pitchers. However, the timing of each variable within the pitching cycle occurred approximately 10% earlier in the younger pitchers. The findings suggest differences in pitching mechanics exist between younger and more experienced populations. Level of Evidence: Level 3.

Test-Retest Reliability of the Closed Kinetic Chain Upper Extremity Stability Test (CKCUEST) in a Modified Test Position in Division I Collegiate Basketball Players.

BACKGROUND: The closed kinetic chain upper extremity stability test (CKCUEST) as originally described may not be appropriate for assessing athletes interchangeably considering body size variations. A modified test position may be warranted to normalize the CKCUEST to body size, in order to reflect an accurate representation of upper limb function. PURPOSE: To determine test-retest reliability of the CKCUEST in a modified test position in Division I collegiate basketball players. STUDY DESIGN: Test-retest reliability. METHODS: 15 subjects (8 male, 7 female) were recruited from Division I basketball teams. Subjects began in a push-up position with their hands located directly under their shoulders. Subjects performed one 15 second trial of the modified CKCUEST initially and a second trial one week later. Hand-written data was transferred to a spreadsheet for analysis using Minitab Statistical Software for comparison. RESULTS: Test-retest reliability was 0.88 for men's basketball, 0.79 for women's basketball, and 0.90 when both teams were combined. Test mean for men's basketball were 29.5 ± 4.78, and retest mean were 31.88 ± 4.99. Test mean for women's basketball were 24.86 ± 5.52, and retest mean were 26.71 ± 5.41. Test mean for both teams combined were 27.33 ± 5.5, and retest mean were 29.47 ± 5.67. CONCLUSIONS: The CKCUEST in a modified test position is a reliable assessment tool. Results support previous findings and may contribute to injury prevention and return to sport decision-making. LEVEL OF EVIDENCE: 3b.

Knee mechanics during a change of direction movement in division I athletes following full return to sport from anterior cruciate ligament reconstruction.

OBJECTIVES: The objective of this study was to determine whether Division I athletes following anterior cruciate ligament reconstruction (ACLR), and who are medically cleared to return to sport, demonstrate faulty knee mechanics during a change of direction maneuver, as evidenced by the presence of genu valgum on VICON® motion analysis system of 5° or greater. STUDY DESIGN: Cross-sectional study. SETTING: University. PARTICIPANTS: Ten Division I athletes performed a 90° change of direction movement on both the ACLR and unaffected limbs. MAIN OUTCOME MEASURES: Knee mechanics were assessed using the VICON® motion analysis system. Knee position was analyzed in the frontal plane and peak genu valgum position was determined during the functional movement. RESULTS: Eight out of ten athletes (80%) demonstrated genu valgum ≥ 5° on the ACLR limb during a 90° cutting movement. Fourteen out of twenty (70%) of the knees assessed demonstrated genu valgum ≥ 5° during a 90° cutting movement. CONCLUSION: Athletes who have fully returned to sport following an ACLR demonstrate substantial genu valgum during a cutting maneuver, which suggests an increased risk for future injury. These results show an increased need during ACL rehabilitation to focus on existing biomechanical deficits during sport-specific movements.

The balance error scoring system learned response among young adults.

BACKGROUND: Concussion management practices are important for athlete safety. Baseline testing provides a benchmark to which post-injury assessments are compared. Yet few neurophysical concussion assessment studies have examined learned response. The Balance Error Scoring System (BESS) measures postural stability through 6 conditions by counting the errors committed during each condition. In a study examining the performance of high school-aged athletes on the BESS, the learned response extinguished in 3 weeks. However, this phenomenon has not been studied in the college-aged population. HYPOTHESIS: College-aged adults performing the BESS will have a learned response at 1 and 2 weeks but would have no change from baseline at or after 3 weeks, as found previously in high school-aged subjects. STUDY DESIGN: Randomized controlled clinical trial. METHODS: Three groups of college-aged adults ages 18 to 26 years were tested using the BESS at scheduled intervals. Each subject was randomly assigned into 1 of 3 groups to determine learned response at weeks 1, 2, and 4. Changes in pretest and posttest BESS scores were compared using the paired t test for each group at week 4 and other intervals. Differences among groups were compared using analysis of variance for means or the chi-square test for proportions. RESULTS: After 4 weeks, participants exhibited a mean (95% confidence interval) change from pretest baseline of -2.30 (-4.75, 0.16) in the control group (P = 0.065), -3.13 (-4.84, -1.41) in Group 1 (P = 0.001), and -2.57 (-5.28, 0.15) in Group 2 (P = 0.063). There were no statistically significant differences between the 3 groups for week 4 BESS score (P = 0.291) or changes from baseline to week 4 BESS scores (P = 0.868). Overall, participant score changes from baseline to the 4-week follow-up still showed a statistically significant or close to significant reduction across the 3 groups, indicating the learned response did not extinguish after 4 weeks. CONCLUSION: Repeated BESS testing results in a learned effect in college-aged adults did not extinguish after 4 weeks. These results question the ability of the BESS to assess an athlete's balance deficits following a concussion. CLINICAL RELEVANCE: Given learned response did not extinguish in this sample and the BESS has a minimal detectable change/reliable change index of 7 or greater, the effectiveness of the BESS to assess balance may be limited.

Prevalence of neurocognitive and balance deficits in collegiate aged football players without clinically diagnosed concussion.

STUDY DESIGN: Prospective cohort. OBJECTIVES: To identify the prevalence of neurocognitive and balance deficits in collegiate football players 48 hours following competition. BACKGROUND: Neurocognitive testing, balance assessments, and subjective report of symptoms are a commonly used test battery in examining athletes when concussion is suspected. Previous literature suggests many concussions go unreported. Little research exists examining the prevalence of neurocognitive or balance deficits in athletes who do not report concussion-like symptoms to a health care provider. METHODS: Forty-five Division IA collegiate football players participated in this study. Preseason baseline scores using the Balance Error Scoring System, the Immediate Post-Concussion Assessment and Cognitive Testing, and the Postconcussion Symptom Scale were compared to posttest results obtained 48 hours following a game. Prevalence of symptoms was analyzed and reported. RESULTS: Thirty-two (71%) of the 45 athletes tested demonstrated at least 1 deficit in either the Postconcussion Symptom Scale, Balance Error Scoring System, or at least 1 composite score of the Immediate Post-Concussion Assessment and Cognitive Testing. Nineteen of the 32 subjects demonstrated a change in 2 or more categories of neurocognitive and balance function. CONCLUSION: In a cohort of football players tested 48 hours following their last game of the season, who did not seek medical attention related to a concussion, a significant number demonstrated limitations in neurocognitive and balance performance, suggesting that further research may need to be performed to improve recognition of an athlete's deficits and to improve the ability to assess concussion. LEVEL OF EVIDENCE: Differential diagnosis/symptom prevalence, level 3b.

A novel cryotherapy compression wrap in the management of acute ankle sprains: potential use for special operators on the battlefield.

OBJECTIVE: Musculoskeletal injuries related to training and operational missions frequently affect military personnel. A common treatment for these injuries is the PRICE (protection, rest, ice, compression, and elevation) method, which is time consuming and impractical in the field. Therefore, the primary objective of this study was to determine the effectiveness of the cryotherapy wrap compared to a traditional treatment in the management of acute ankle sprains. METHODS: A randomized controlled clinical trial was conducted in a university research laboratory with 13 subjects (9 males and 4 females) with the following physical characteristics: age (yr) 20.6 ? 2.2, height (cm) 177.0 ? 14.3, weight (kg) 76.6 ? 20.6, and body mass index (kg/m2) 24.1 ? 3.7. Participants were instructed to perform PRICE with a traditional ice pack and compression wrap (control group) or with an Arctic Ease? cryotherapy wrap (test group) for 48 hours following enrollment in the study. The Numeric Pain Scale, Foot and Ankle Ability Measure, and ankle/foot volumetric measurement were performed at initial presentation and 24-hour, 48-hour, and 7-day follow-up intervals. RESULTS: While the comparison of the Numeric Pain Scale scores, Foot and Ankle Ability Measure scores, and volumetric changes between groups revealed no statistically significant differences (p > 0.01), there was an 86% compliance rate for subjects in the cryotherapy wrap group compared to a 17% compliance rate of subjects in the control group. CONCLUSIONS: The cryotherapy wraps performed comparably to ice therapy and therefore may be especially applicable to military personnel required to operate in austere and hostile environments where traditional therapies are unrealistic. Although this pilot study did not demonstrate that the cryotherapy wraps produce statistically superior results, trends emerged in the data suggesting that subject compliance rate may be improved by using an alternative form of cryotherapy compression, which could lead to better management of pain, edema, and functional recovery. Future research should include a larger sample size to verify this claim.

Isokinetic profile of shoulder internal and external rotators of high school aged baseball pitchers.

The purpose of this descriptive study was to determine whether bilateral differences exist in concentric and eccentric shoulder internal and external rotation strength in high school aged baseball pitchers. Thirty-nine high school aged baseball pitchers were bilaterally tested for concentric and eccentric internal and external rotation muscle performance on a Kin-Com 500-H isokinetic dynamometer at 90 degrees .s(-1) and 180 degrees .s(-1). Paired t-tests were used to test for differences among extremities, speed, and ratio of external rotation to internal rotation (ER/IR ratios). Concentric peak torque internal rotation at 90 degrees .s(-1) was significantly greater (p < 0.05) in the dominant arm compared with the nondominant arm. Statistically significant differences (p < 0.001) were found between the nondominant and dominant in concentric 90 degrees .s(-1). The nondominant arm demonstrated significantly greater eccentric strength (p < 0.05) compared with the dominant arm in ER/IR ratios at 90 degrees .s(-1) and 180 degrees .s(-1). The nondominant arm demonstrated significantly greater eccentric strength (p < 0.05) than the dominant arm in ER/IR ratio at 180 degrees .s(-1). Data demonstrated that muscular adaptations are consistent with previous research in this area. Also, muscular adaptations occur in the shoulder in the high school aged population. These data can serve as a guideline to be used by clinicians who rehabilitate shoulders in patients in this population.