Comparison of a Combined Strength and Handball-Specific Training vs. Isolated Strength Training in Handball Players Studying Physical Education.

OBJECTIVES: The purpose of this study was to compare the effect of combined resistance training including handball-specific drill (CRT) with resistance training excluding handball-specific drill training (NSDT). MATERIALS AND METHODS: Twenty-two male handball players who studied physical education were randomly assigned to two groups: CRT (combined resistance training with sport-specific drill; n = 12) and NSDT (resistance training without any sport-specific drill training; n = 10). Over a 10-week period during the competitive season, the players performed a specific training program twice per week, which replaced their normal team handball training. The CRT regimen consisted of a combined (associated) resistance training and handball-specific drill, whereas the NSDT program consisted of a resistance training without handball-specific drill (dissociated). Pre- and post-test measures included squat jump and countermovement jumps, bench press, back half squats, throwing velocity during a 3-step jump throw, and a jump shot, repeated-sprint ability (six 2 × 15-m shuttle sprints) (RSA), medicine ball throw and anthropometric measurements. RESULTS: In both groups, significant intervention effects (d ≥ 1.0) were seen for all sprint (3/3), throwing (3/3) and jump (2/2) measures. Regarding maximal strength parameters, an effect size lower than 0.5 was only detected in the NSDT group for half back squats (d = 0.48). The largest effects were observed in the NSDT group for squat jump (d = 6.20) and medicine ball throw (d = 6.07). Interaction effects (group × time) were found for 50 % (5/10) of parameters. The greatest difference between groups regarding performance development over time was detected for jump shot (interaction effect: η²â€Š= 0.748). In contrast, there was no difference in performance development in both groups over time for RSAbest (interaction effect: η²â€Š= 0.025). CONCLUSIONS: The current findings suggest that during the competitive season, 10 weeks of CRT with only two training sessions per week improved numerous measures of athletic performance in handball students of physical education. Such conditioning should be highly recommended as part of the annual training program of handball players.

Differences in Player Position Running Velocity at Lactate Thresholds Among Male Professional German Soccer Players.

This study investigated the differences in running velocities at specific lactate thresholds among male German soccer players. One hundred fifty-two professional (3rd league: n = 78; 4th league: n = 74) male soccer players (mean ± SD; age: 24.7 ± 4.37 years, body mass: 80.8 ± 7.33 kg, body height: 1.83 ± 0.06 m) volunteered for the investigation. Players were categorized as goalkeepers, central defenders, central midfielders, wings and forward. Players completed a treadmill test, at incremental speeds, to determine running velocity at different blood lactate concentrations (v2 = 2 mmol/l; v4 = 4 mmol/l; and v6 = 6 mmol/l). In addition, the largest difference between positions for running velocity was found at the lactate threshold v2 (p = 0.005). The running data revealed that only goalkeepers had significantly lower velocities at the lactate thresholds compared to outfield players. The central midfielders showed the highest average performance level at the lactate thresholds (v2: 12.5 ± 1.20 km/h; v4: 15.2 ± 1.14 km/h; and v6: 16.6 ± 1.14 km/h). In conclusion, this study provides soccer and position-specific reference data for the running performance of male professional German soccer players to evaluate the endurance performance in a standardized way. In this context, future research should extend the database for the first and second leagues. Further research assessing running performance during competition matches over the entire season is required to validate the endurance test performance data.

Does low back pain affect the reliability of postural regulation?

The aim of this study was to examine the intraobserver reliability of a posturographic assessment in patients with low back pain. We investigated 24 symptomatic subjects with defined low back pain (mean: 57.9 years) and a pair-matched control group including 24 asymptomatic persons (mean: 58.1 years). Each participant underwent two measurements on a posturographic device (32 Hz sampling rate) based on the Interactive Balance System (time interval: 7 d). Test procedure consisted of tests on solid ground with eyes open (1) and eyes closed (2). Data analysis included parameters of motor output and a frequency band analysis. Reliability tests were realized using by intraclass correlations (ICC). Coefficients of ICC ranged from 0.36 (95% CI: 0.01-0.73) to 0.94 (95% CI: 0.86-0.97) in both test positions. For 69% (11/16) of the investigated parameters a high level (ICC > 0.75) of intraobserver reliability was reached. Based on the results, the posturographic measurement system used in this study seems to be appropriate for use in longitudinal study designs in an orthopaedic setting.

The influence of lumbopelvic control on shoulder and elbow kinetics in elite baseball pitchers.

BACKGROUND: Research has shown that diminished lumbopelvic control has a negative effect on pitching performance and can lead to more days on the disabled list. Despite the identified correlation between lumbopelvic control and injury, there is no research that has shown whether insufficient lumbopelvic control increases the force placed on the throwing arm. METHODS: Forty-three asymptomatic, National Collegiate Athletic Association Division I and professional minor league baseball pitchers participated. We measured the bilateral amount of anterior-posterior lumbopelvic tilt during a single-leg stance trunk stability test. We measured the shoulder and elbow kinetics of the throwing arm during the pitching motion using a 3-dimensional, high-speed video capture system. We used 2-tailed Pearson product-moment correlation coefficients (r) to determine the strength of the relationships between variables (P < .05). RESULTS: There were no significant relationships between the stride leg and any of the pitching kinetic variables (r < 0.23, P > .14). Similarly, there were no significant relationships between the drive leg and maximum shoulder distraction force, shoulder external rotation torque, or elbow distraction force (r <-0.24, P > .13). However, the drive leg did have significant relationships with both maximum shoulder horizontal torque (r = 0.44, P = .003) and elbow valgus torque (r = 0.46, P = .002). CONCLUSIONS: Our results show that a relationship exists between lumbopelvic control of the drive leg and both shoulder horizontal torque and elbow valgus torque during the throwing motion. Because of these relationships, clinicians should consider incorporating lumbopelvic control training exercises to minimize the kinetic force placed on the throwing shoulder and elbow during the pitching motion.

ACUTE EFFECTS OF MUSCLE ENERGY TECHNIQUE AND JOINT MOBILIZATION ON SHOULDER TIGHTNESS IN YOUTH THROWING ATHLETES: A RANDOMIZED CONTROLLED TRIAL.

BACKGROUND: Posterior shoulder tightness (PST), defined as limited glenohumeral (GH) horizontal adduction and internal rotation motion, is a common occurrence in overhead athletes, particularly baseball and softball players, as a result of the extreme forces on the GH joint and the high number of throwing repetitions. Despite clinical evidence suggesting the use of joint mobilizations and muscle energy techniques (MET) for treating PST, there currently are no data examining the overall effectiveness of joint mobilizations and MET to determine optimal treatment for posterior shoulder tightness. PURPOSE: To compare the acute effectiveness of MET and joint mobilizations for reducing posterior shoulder tightness, as measured by passive GH horizontal adduction and internal rotation ROM, among high school baseball and softball players. STUDY DESIGN: Randomized controlled study. METHODS: Forty-two asymptomatic high school baseball and softball players were randomly assigned to one of three groups (14 MET, 14 joint mobilization, 14 control). Glenohumeral passive adduction and internal rotation ROM were measured in all participants in a pre-test post-test fashion. Between testing, the joint mobilization group received one application of GH posterior joint mobilizations. The MET group received one cycle of MET applied to the GH horizontal abductors. The control group received no intervention. Posttests measures were completed immediately following intervention or a similar amount of time resting for the control group and then again 15 minutes later. RESULTS: One-way analyses of covariance showed that the MET group had significantly more horizontal adduction ROM post-treatment compared to the control group (p = 0.04). No significant differences existed between groups in horizontal adduction (p > 0.16) or internal rotation (p>.28) or at the 15-minute posttests (p > 0.70). CONCLUSION: The results of this study indicate the application of MET to the horizontal abductors provides acute improvements to GH horizontal adduction ROM in high school baseball and softball players, while joint mobilizations provide no improvements. LEVEL OF EVIDENCE: 1.

Reliability of an ice hockey-specific complex test.

BACKGROUND: This study assessed the intra-rater reliability of an ice hockey-specific complex test (IHCT) that reflects the intense multidirectional and intermittent efforts required in ice hockey. METHODS: Twenty professional players executed the IHCT twice over an interval of 2 days. Load parameters included a 10-m sprint, a 30-m transition with and without a puck, as well as slap and wrist shots. Stress parameters were lactate concentrations and heart rates. RESULTS: The intrarater reliability (ICC) ranged from 0.54 to 0.98 for load parameters, and from 0.26 to 0.87 for stress parameters. 33 % (3/9) of stress parameters and 82 % (18/22) of load parameters had an ICC > 0.75. The largest limits of agreement were 41.6 for slap shot 1 after test and 50.4 for 6-min heart rate recovery. The smallest were 0.40 (10-m sprint without a puck) and 5.36 (resting lactate). The intra-rater reliability as shown by the coefficient of variation (CV) was lower for stress than for load parameters (mean CV: 13.4 vs. 4.7). 68 % (15/22) of load parameters and 11 % (1/9) of stress parameters showed a CV below 5 %. CONCLUSION: The IHCT is currently the only ice hockey-specific complex test with scientifically tested reliability and validity that can analyze performance under conditions similar to competition. It is suggested that coaches, fitness coaches and sports scientists explore use of this test as a valid tool to assess players' performance and the effectiveness of training interventions.

National Athletic Trainers' Association Position Statement: Evaluation, Management, and Outcomes of and Return-to- Play Criteria for Overhead Athletes With Superior Labral Anterior-Posterior Injuries.

OBJECTIVE: To present recommendations for the diagnosis, management, outcomes, and return to play of athletes with superior labral anterior-posterior (SLAP) injuries. BACKGROUND: In overhead athletes, SLAP tears are common as either acute or chronic injuries. The clinical guidelines presented here were developed based on a systematic review of the current evidence and the consensus of the writing panel. Clinicians can use these guidelines to inform decision making regarding the diagnosis, acute and long-term conservative and surgical treatment, and expected outcomes of and return-to-play guidelines for athletes with SLAP injuries. RECOMMENDATIONS: Physical examination tests may aid diagnosis; 6 tests are recommended for confirming and 1 test is recommended for ruling out a SLAP lesion. Combinations of tests may be helpful to diagnose SLAP lesions. Clinical trials directly comparing outcomes between surgical and nonoperative management are absent; however, in cohort trials, the reports of function and return-to-sport outcomes are similar for each management approach. Nonoperative management that includes rehabilitation, nonsteroidal anti-inflammatory drugs, and corticosteroid injections is recommended as the first line of treatment. Rehabilitation should address deficits in shoulder internal rotation, total arc of motion, and horizontal-adduction motion, as well as periscapular and glenohumeral muscle strength, endurance, and neuromuscular control. Most researchers have examined the outcomes of surgical management and found high levels of satisfaction and return of shoulder function, but the ability to return to sport varied widely, with 20% to 94% of patients returning to their sport after surgical or nonoperative management. On average, 55% of athletes returned to full participation in prior sports, but overhead athletes had a lower average return of 45%. Additional work is needed to define the criteria for diagnosing and guiding clinical decision making to optimize outcomes and return to play.

Pre- and postoperative postural regulation following anterior cruciate ligament reconstruction.

There are currently no longitudinal data describing the pre- and postoperative postural regulation and stability of patients with anterior cruciate ligament (ACL) damage. Therefore, the aim of this study was to evaluate postural regulation and stability prior to and during rehabilitation following surgery of the ACL. Fifty-four physically active subjects (age: 30.5±10.9 years, 29 male subjects) were examined with the Interactive Balance System pre-, 6, and at 12 weeks following surgical reconstruction of the ACL using a hamstring tendon graft. The average period of time from injury to surgery was 27 days. Data were calculated with unifactorial and univariate analysis of variance. Significant effects were found for the somatosensory system (η2=0.115), stability indicator (η2=0.123), weight distribution index (η2=0.176), and synchronization (foot coordination) (η2=0.249). Involved side weight distribution (parameter: left) increased significantly (patients with left-sided/right-sided injury: η2=0.234/0.272). Load distribution to the heel remained stable during all three examination periods (η2=0.035 and η2=0.071), although a remarkable load at forefoot was observed. In seven out of 10 parameters partial effects were seen during the first 6 weeks after surgery. The results of this study indicated that injury of the ACL and subsequent surgical reconstructions result in postural regulation, with improvements in somatosensory system function, postural stability, weight distribution index, and foot coordination. Also, overloading of the injured side on the feet reduces significantly during rehabilitation. Thus, the initial phase of rehabilitation (weeks 1 to 6) seems to be more effective than the second period (weeks 6 to 12) postoperatively.

Descriptive Profile of Lumbopelvic Control in Collegiate Baseball Pitchers.

Laudner, K, Wong, R, Latal, J, and Meister, K. Descriptive profile of lumbopelvic control in collegiate baseball pitchers. J Strength Cond Res 32(4): 1150-1154, 2018-Throwing a baseball requires the transmission of forces generated in the lower extremity, through the trunk, then to the upper extremity, and ultimately out through the ball. Disruptions in this kinetic chain, specifically in lumbopelvic control, have been associated with decreased pitching performance and increased risk of injury. The purpose of this study was to establish normative data of lumbopelvic control among collegiate baseball pitchers. Data were compared bilaterally and with a group of nonthrowing physically active individuals. Eighteen asymptomatic pitchers and 30 nonthrowing subjects participated in this study. Each subject performed 6 separate tests bilaterally: single-leg balance, single-leg mini-squat, and static single-leg bridge. An iPod-based tilt sensor was placed around the waist of each subject and used to determine the amount of anterior-posterior lumbopelvic tilt during each test. Independent t tests showed that neither group had any bilateral differences in lumbopelvic control (p > 0.10). The groups had similar lumbopelvic tilt values during the single-leg balance (p > 0.08) and mini-squat tests (p > 0.72), but a significant difference during the bridge maneuver. For this test, the pitchers had less lumbopelvic control than the control group for both the lead leg (p = 0.003) and trail leg (p = 0.01). The descriptive values of this study may assist in designing lumbopelvic conditioning programs with the intent of enhancing pitching performance, as well as in the prevention, evaluation, and treatment of various injuries associated with lumbopelvic control deviations.

Treadmill based reference running data for healthy subjects is dependent on speed and morphological parameters.

OBJECTIVE: To obtain spatiotemporal and dynamic running parameters of healthy participants and to identify relationships between running parameters, speed, and physical characteristics. METHOD: A dynamometric treadmill was used to collect running data among 417 asymptomatic subjects during speeds ranging from 10 to 24km/h. Spatiotemporal and dynamic running parameters were calculated and measured. RESULTS: Results of the analyses showed that assessing running parameters is dependent on running speed. Body height correlated with stride length (r=0.5), cadence (r=-0.5) and plantar forefoot force (r=0.6). Body mass also had a strong relationship to plantar forefoot forces at 14 and 24km/h and plantar midfoot forces at 14 and 24km/h. CONCLUSION: This reference data base can be used in the kinematic and kinetic evaluation of running under a wide range of speeds.

Differences in anthropometric characteristics in relation to throwing velocity and competitive level in professional male team handball: a tool for talent profiling.

BACKGROUND: The primary aim of the study was to examine the anthropometric characteristics as well as throwing and sprinting performance of professional handball players classified by playing position and competition level. METHODS: 21 male players (age: 25.2±5.1 years) from the first German handball league (FGL) and 34 male players (age: 26.1±4.1 years) from the third German handball league (TGL) were categorized as backs, pivots, wings and goalkeepers. Measurements included anthropometric data (height, mass and body mass index (BMI)), throwing and sprinting performance selected out of a complex handball test (HBCT), which was conducted twice (2 rounds). During the HBCT, the subjects performed two sprints (10, 20 m), two standing throws with run-up (ST) and four vertical jump throws (VJT) over a hurdle (20 cm) with and without precision for goal shot. RESULTS: The anthropometric data revealed a significantly (P=0.038 and η2=0.079) shorter body height for TGL than for FGL players. In the cohort of first league athletes the pivots were the tallest (1.98±0.04 m), backs in the third league showed the maximum body height (1.90±0.05 m). Regarding body mass, pivots were the heaviest players independent from the league membership. The FGL players showed a significantly (P<0.05 and η2>0.10) higher throwing velocity in all type of throws. Body height was significantly related to ST (r=0.53) and VJT (r=0.52) in the first round of HBCT but only for the FGL athletes. Throwing velocity was also correlated with BMI (r=-0.50) among the TGL players. CONCLUSIONS: Substantial differences of body characteristics, throwing and sprinting performance between playing positions and competitive levels underline the importance of a careful scouting and position-specific training for professional handball players.

Inter- and intrarater reliability of goniometry and hand held dynamometry for patients with subacromial impingement syndrome.

The purpose of this study was to examine the intra- and interrater reliability of measuring shoulder range of motion (ROM) and strength among patients diagnosed with subacromial impingement syndrome (SAIS). Twenty-five patients (14 female patients; mean age, 60.4± 7.84 years) diagnosed with SAIS were assessed to determine the intrarater reliability for glenohumeral ROM. Twenty-five patients (16 female patients; mean age, 60.4± 7.80 years) and 76 asymptomatic volunteers (52 female volunteers; mean age, 29.4± 14.1 years) were assessed for interrater reliability. Dependent variables were active shoulder ROM and isometric strength. Intrarater reliability was fair-to-excellent for the SAIS patients (intraclass correlation coefficient [ICC], 0.52-0.97; standard error of measurement [SEM], 4.4°-9.9° N; coefficient of variation [CV], 7.1%-44.9%). Based on the ICC, 11 of 12 parameters (92%) displayed an excellent reliability (ICC> 0.75). The interrater reliability showed fair-to-excellent results (SAIS patients: ICC, 0.13-0.98; SEM, 2.3°-8.8°; CV, 3.6%-37.0%; controls: ICC, 0.11-0.96; SEM, 3.0°-35.4°; CV, 5.6%-26.4%). In accordance with the intrarater reliability, glenohumeral adduction ROM was the only parameter with an ICC below 0.75 for both samples. Painful shoulder ROM in the SAIS patients showed no influence on the quality of reliability for measurement. Therefore, these protocols should be considered reliable assessment techniques in the prevention, diagnosis, and treatment of painful shoulder conditions such as SAIS.

Effect of Swim Training on the Physical Characteristics of Competitive Adolescent Swimmers.

BACKGROUND: Subacromial space distance and forward head and shoulder posture are common characteristics resulting from swim training. These alterations can cause abnormal scapular kinematics and positioning, potentially increasing compression of structures in the subacromial space and increasing the risk for the development of swimmer's shoulder. PURPOSE: To evaluate the effect of the swim training season on subacromial space distance and forward head and forward shoulder posture as well as to determine the relationship between these variables. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: Included in the study were 43 competitive adolescent swimmers and 29 nonoverhead adolescent athletes (controls) who were not currently experiencing any shoulder, neck, or back pain that limited their participation in sports activity. All participants were evaluated 3 times: once before the start of the swim training season and then at 2 follow-up sessions 6 and 12 weeks after the initial testing session. At each testing session, each participant completed a physical examination that included evaluation of posture and subacromial space distance. RESULTS: Swimmers had significantly greater decreases in subacromial space distance during the training season compared with nonoverhead athletes. Swimmers also demonstrated significantly greater increases in forward shoulder posture compared with nonoverhead athletes. A significant relationship was noted between changes in forward shoulder posture and changes in subacromial space distance from the baseline testing session to the assessment 6 weeks after baseline assessment. As forward shoulder posture increased, subacromial space significantly decreased. CONCLUSION: Because of their training load, swimmers experience a decrease in subacromial space distance and an increase in forward shoulder posture over the course of 12 weeks of training, potentially making these athletes more vulnerable to the development of shoulder pain and injury.

Effect of Ankle Positioning During Hamstring Stretches for Improving Straight Leg Hip Flexion Motion.

OBJECTIVE: To compare the effects of stretching the hamstrings with the ankle in either a plantar-flexed (PF) or dorsiflexed (DF) position for improving straight leg hip flexion range of motion (ROM) over a 4-week period. DESIGN: Randomized, single-blinded, pretest, posttest design. SETTING: Athletic training facility. PARTICIPANTS: Each limb of 34 asymptomatic individuals (15 males, 19 females) was randomly assigned to one of the 3 groups. Twenty-four limbs received hamstring stretches with the ankle in DF, 24 limbs received hamstring stretches with the ankle in PF, and 20 limbs received no stretch (control). INDEPENDENT VARIABLES: Ankle position (PF, DF) during hamstring stretching. MAIN OUTCOME MEASURES: We measured pretest and posttest passive straight leg hip flexion ROM with the test ankle in a neutral position. For the intervention groups, the test limb was passively stretched with the ankle held in end range DF or PF for their respective group. Each stretch was held for 30 seconds for a total of 3 applications. Two treatment sessions were completed per week for a total of 4 weeks. The control limbs received no stretching during the 4-week period. We conducted 1-way analyses of covariance to determine significant changes in ROM between groups (P < 0.05). RESULTS: There was no significant difference between treatment groups (P = 0.90), but a significant difference was found for both the PF (P = 0.04) and DF (P = 0.01) groups when compared with the control group. CONCLUSIONS: Our findings indicate that both stretching the hamstrings in either PF or DF improve straight leg hip ROM compared with a control group. CLINICAL RELEVANCE: The results of this study should be considered by clinicians when determining the optimal stretching techniques aimed at increasing hamstring length.

Forward Shoulder Posture in Collegiate Swimmers: A Comparative Analysis of Muscle-Energy Techniques.

CONTEXT: Empirical data for treating forward shoulder posture supports stretching the anterior shoulder musculature. Although muscle-energy techniques (METs) have been hypothesized to lengthen muscle, no data have described the usefulness of this technique among swimmers. OBJECTIVE: To determine if an MET provides improvements in resting pectoralis minor length (PML), forward scapular position, and scapular upward rotation in female collegiate swimmers. DESIGN: Controlled laboratory study. SETTING: Athletic training room. PATIENTS OR OTHER PARTICIPANTS: Thirty-nine asymptomatic National Collegiate Athletic Association Division I women's swimmers (19 experimental, 20 control). INTERVENTION(S): The experimental group received 2 treatment sessions per week for 6 weeks. The control group received no intervention during this 6-week period. MAIN OUTCOME MEASURE(S): We administered pretest and posttest measurements for PML, forward scapular position, and scapular upward rotation in positions of rest and 60°, 90°, and 120° of humeral elevation. The MET consisted of a 3-second stretch in the direction of the pectoralis minor fibers, followed by a 5-second isometric horizontal adduction contraction at 25% of maximum force. Immediately after this contraction, the entire sequence was repeated with the muscle being stretched to the new endpoint. A total of 4 cycles of MET were continuously applied per treatment session twice per week for 6 weeks. We conducted 1-way analyses of covariance to determine any between-groups postintervention test differences. RESULTS: The MET group had a greater increase in PML postintervention (P = .001, effect size = 1.6) and a greater decrease in forward scapular position postintervention (P = .001, effect size = 1.07) compared with the control group. No differences were found for scapular upward rotation (P > .10). CONCLUSIONS: Our results indicate that 6 weeks of MET treatments applied to the pectoralis minor of asymptomatic female swimmers provided improvements in PML and forward scapular position compared with a control group.

Intrarater reliability of goniometry and hand-held dynamometry for shoulder and elbow examinations in female team handball athletes and asymptomatic volunteers.

INTRODUCTION: To evaluate the intrarater reliability for examining active range of motion (ROM) and isometric strength of the shoulder and elbow among asymptomatic female team handball athletes and a control group using a manual goniometer and hand-held dynamometry (HHD). MATERIALS AND METHODS: 22 female team handball athletes (age: 21.0 ± 3.7 years) and 25 volunteers (13 female, 12 male, age: 21.9 ± 1.24 years) participated to determine bilateral ROM for shoulder rotation and elbow flexion/extension, as well as isometric shoulder rotation and elbow flexion/extension strength. Subjects were assessed on two separate test sessions with 7 days between sessions. Relative (intraclass correlation coefficients (ICC) and standard error of measurement (SEM) reliability were calculated. RESULTS: Reliability for ROM and strength were good to excellent for both shoulders and groups (athletes: ICC = 0.94-0.97, SEM 1.07°-4.76 N, controls: ICC = 0.96-1.00, SEM = 0.00 N-4.48 N). Elbow measurements for both groups also showed good-to-excellent reliability (athletes: ICC = 0.79-0.97, SEM = 0.98°-5.94 N, controls: ICC = 0.87-1.00, SEM = 0.00 N-5.43 N). CONCLUSIONS: It is important to be able to reliably reproduce active ROM and isometric strength evaluations. Using a standardized testing position, goniometry and HHD are reliable instruments in the assessment of shoulder and elbow joint performance testing. We showed good-to-excellent reproducible results for male and female control subjects and female handball athletes, although the single parameters in ROM and strength were different for each group and between the shoulders and elbows.

Correlation of Shoulder and Elbow Kinetics With Ball Velocity in Collegiate Baseball Pitchers.

CONTEXT: Throwing a baseball is a dynamic and violent act that places large magnitudes of stress on the shoulder and elbow. Specific injuries at the elbow and glenohumeral joints have been linked to several kinetic variables throughout the throwing motion. However, very little research has directly examined the relationship between these kinetic variables and ball velocity. OBJECTIVE: To examine the correlation of peak ball velocity with elbow-valgus torque, shoulder external-rotation torque, and shoulder-distraction force in a group of collegiate baseball pitchers. DESIGN: Cross-sectional study. SETTING: Motion-analysis laboratory. PATIENTS OR OTHER PARTICIPANTS: Sixty-seven asymptomatic National Collegiate Athletic Association Division I baseball pitchers (age = 19.5 ± 1.2 years, height = 186.2 ± 5.7 cm, mass = 86.7 ± 7.0 kg; 48 right handed, 19 left handed). MAIN OUTCOME MEASURE(S): We measured peak ball velocity using a radar gun and shoulder and elbow kinetics of the throwing arm using 8 electronically synchronized, high-speed digital cameras. We placed 26 reflective markers on anatomical landmarks of each participant to track 3-dimensional coordinate data. The average data from the 3 highest-velocity fastballs thrown for strikes were used for data analysis. We calculated a Pearson correlation coefficient to determine the associations between ball velocity and peak elbow-valgus torque, shoulder-distraction force, and shoulder external-rotation torque (P < .05). RESULTS: A weak positive correlation was found between ball velocity and shoulder-distraction force (r = 0.257; 95% confidence interval [CI] = 0.02, 0.47; r(2) = 0.066; P = .018). However, no significant correlations were noted between ball velocity and elbow-valgus torque (r = 0.199; 95% CI = -0.043, 0.419; r(2) = 0.040; P = .053) or shoulder external-rotation torque (r = 0.097; 95% CI = -0.147, 0.329; r(2) = 0.009; P = .217). CONCLUSIONS: Although a weak positive correlation was present between ball velocity and shoulder-distraction force, no significant association was seen between ball velocity and elbow-valgus torque or shoulder external-rotation torque. Therefore, other factors, such as improper pitching mechanics, may contribute more to increases in joint kinetics than peak ball velocity.

Decreased blood flow in the throwing arm of professional baseball pitchers.

BACKGROUND: As a consequence of the repetitive forces placed on the throwing arm of a baseball player, various bony, capsuloligamentous, and muscular adaptations occur and have been identified. However, no research has identified whether adaptations also exist in the vasculature of the upper extremity in the competitive baseball player. METHODS: Fifty-one professional baseball pitchers and 34 position players participated. Diagnostic ultrasound was used to measure bilateral blood flow of the brachial artery. These measurements were taken with the participant standing with the test arm resting at the participant's side and again with the test arm in a provocative shoulder position. RESULTS: The throwing arm of the pitchers had significantly less blood flow volume when in the provocative shoulder position compared with their nonthrowing arm (P = .01). Pitchers did not have any bilateral difference while in the resting position (P = .19). There were no bilateral differences among the position players while in the resting (P = .64) or provocative positions (P = .63). Pitchers had significantly less blood flow of the throwing shoulder while in the provocative position compared with position players (P = .02). There were no other between-group differences. CONCLUSIONS: While in a provocative shoulder position, pitchers have significantly less blood flow in their throwing arm compared with their nonthrowing arm and with the throwing arm of position players. These results provide a descriptive profile of blood flow volume among baseball players, which may be used in the evaluation and treatment of such athletes with vascular disorders.

Adductor longus activation during common hip exercises.

CONTEXT: Hip-adductor strains are among the most common lower-extremity injuries sustained in athletics. Treatment of these injuries involves a variety of exercises used to target the hip adductors. OBJECTIVE: To identify the varying activation levels of the adductor longus during common hip-adductor exercises. DESIGN: Descriptive study. SETTING: Laboratory. PARTICIPANTS: 24 physically active, college-age students. INTERVENTION: None. MAIN MEASUREMENT OUTCOMES: Peak and average electromyographic (EMG) activity of the adductor longus muscle during the following 6 hip-adductor rehabilitation exercises: side-lying hip adduction, ball squeezes, rotational squats, sumo squats, standing hip adduction on a Swiss ball, and side lunges. RESULTS: The side-lying hip-adduction exercise produced more peak and average activation than any other exercise (P < .001). Ball squeezes produced more peak and average activation than rotational squats, sumo squats, and standing adduction on a Swiss ball (P < .001). Ball squeezes had more average activation than side lunges (P = .001). All other variables for peak activation during the exercises were not statistically significant (P > .08). These results allowed the authors to provide an overall ranking system (highest to lowest muscle activation): side-lying hip adduction, ball squeezes, side lunges, standing adduction on a Swiss ball, rotational squats, and sumo squats. CONCLUSION: The study provides a ranking system on the activation levels of the adductor longus muscle for 6 common hip-adductor rehabilitation exercises, with the side-lying hip-adduction and ball-squeeze exercises displaying the highest overall activation.

Concussion-assessment and -management techniques used by athletic trainers.

CONTEXT: Understanding concussion-assessmment and -management practices that athletic trainers (ATs) currently use will allow clinicians to identify potential strategies for enhancing the quality of care provided to patients. OBJECTIVE: To assess current clinical concussion diagnostic and return-to-participation practices among ATs. DESIGN: Cross-sectional study. SETTING: Web-based survey. PATIENTS OR OTHER PARTICIPANTS: A link to the survey was sent randomly to a convenience sample of 3222 members of the National Athletic Trainers' Association. A total of 1053 (32.7%) certified ATs (experience as an AT = 11.2 ± 9.1 years) responded to the survey. INTERVENTION(S): Prospective participants received electronic correspondence informing them of the purpose of the study and providing a link to the Web-based survey instrument. A reminder e-mail was sent approximately 6 weeks later, and the survey remained online for a total of 8 weeks. MAIN OUTCOME MEASURE(S): We collected information on the annual number of concussions assessed and tools employed to diagnose, manage, and safely return an athlete to participation. Descriptive statistics were computed for each variable. RESULTS: Participants reported observing 10.7 ± 11.0 concussions per year. Clinical examination (n = 743, 70.6%) was the most commonly reported means for evaluating and diagnosing concussion. Less than half of our respondents employed the Standardized Assessment of Concussion (n = 467, 44.3%), any variation of the Romberg test (n = 461, 43.8%), and computerized neuropsychological testing (n = 459, 43.6%). Clinical examination (n = 773, 73.4%), return-to-participation guidelines (n = 713, 67.7%), physician recommendation (n = 660, 62.7%), or player self-report (n = 447, 42.5%) contributed to the return-to-participation decisions of ATs. Only 20.8% (n = 219) of ATs reported using all 3 recommended domains of the concussion battery. CONCLUSIONS: Our study demonstrated a growth in the number of ATs incorporating objective clinical measures of concussion as a part of their concussion management. Conversely, fewer ATs reported using a standard clinical examination in their concussion assessment. These findings suggest ATs must continue to increase their use of both objective concussion assessment tools and the standard clinical examination.