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Spit (Smokeless) Tobacco Intervention for High School Athletes: results after 1 year.

OBJECTIVE: To determine the efficacy of a spit tobacco (ST) intervention designed to promote ST cessation and discourage ST initiation among male high school baseball athletes. METHODS: This study was a cluster-randomized controlled trial. Forty-four randomly selected high schools in rural California were randomized within strata (prevalence of ST use and number and size of baseball teams) to either the intervention or the control group. Ninety-three percent of eligible baseball athletes participated, yielding 516 subjects in 22 intervention schools and 568 subjects in 22 control schools. Prevalences of sustained ST cessation and ST use initiation over 1 year were assessed by self-report. Multivariate logistic regression models for clustered responses were used to test the null hypotheses of no association between group and the two outcomes, adjusted for the stratified design and baseline imbalances between groups in significant predictors of ST use. RESULTS: Prevalence of cessation was 27% in intervention high schools and 14% in control high schools (odds ratio (OR)=2.29; 95% confidence interval (CI), 1.36-3.87). The intervention was especially effective in promoting cessation among those who, at baseline, lacked confidence that they could quit (OR=6.4; 95% CI, 1.0-4.3), among freshmen (OR=15; 95% CI, 0.9-260), and among nonsmokers (OR=3.2; 95% CI, 0.9-11). There was no significant difference between groups in the prevalence of ST initiation. CONCLUSIONS: This intervention was effective in promoting ST cessation, but was ineffective in preventing initiation of ST use by nonusers.

Adaptation, Psychological↗

Does hard insertion and space improve shock absorption ability of mouthguard?

Mouthguards are expected to reduce sports-related orofacial injuries. Numerous studies have been conduced to improve the shock absorption ability of mouthguards using air cells, sorbothane, metal wire, or hard material insertion. Most of these were shown to be effective; however, the result of each study has not been applied to clinical use. The aim of this study was to develop mouthguards that have sufficient prevention ability and ease of clinical application with focus on a hard insertion and space. Ethylene vinyl acetate (EVA) mouthguard blank used was Drufosoft and the acrylic resin was Biolon (Dreve-Dentamid GMBH, Unna, Germany). Three types of mouthguard samples tested were constructed by means of a Dreve Drufomat (Type SO, Dreve-Dentamid) air pressure machine: the first was a conventional laminated type of EVA mouthguard material; the second was a three layer type with acrylic resin inner layer (hard-insertion); the third was the same as the second but with space that does not come into contact with tooth surfaces (hard + space). As a control, without any mouthguard condition (NOMG) was measured. A pendulum type impact testing machine with interchangeable impact object (steel ball and baseball) and dental study model (D17FE-NC.7PS, Nissin, Tokyo, Japan) with the strain gages (KFG-1-120-D171-11N30C2: Kyowa, Tokyo, Japan) applied to teeth and the accelerometer to the dentition (AS-A YG-2768 100G, Kyowa) were used to measure transmitted forces. Statistical analysis (anova, P < 0.01) showed significant differences among four conditions of NOMG and three different mouthguards in both objects and sensor. About acceleration: in a steel ball which was a harder impact object, shock absorption ability of about 40% was shown with conventional EVA and hard-insertion and about 50% with hard + space. In a baseball that was softer compared with steel ball, a decrease rate is smaller, reduction (EVA = approximately 4%, hard-insertion = approximately 12%, hard + space = approximately 25%) was admitted in the similar order. A significant difference was found with all the combinations except for between EVA and hard-insertion with steel ball (Tukey test). About distortion: both buccal and lingual, distortions had become small in order of EVA, hard-insertion, and hard + space, too. The decrease rate is larger than acceleration, EVA = approximately 47%, hard-insertion = 80% or more, and hard +space = approximately 98%, in steel ball. EVA = approximately 30%, hard-insertion = approximately 75%, and hard + space = approximately 98% in baseball. And a significant difference was found with all the combinations (Tukey test). Especially, hard + space has decreased the distortion of teeth up to several percentages. Acceleration of the maxilla and distortions of the tooth became significantly smaller when wearing any type of mouthguard, in both impact objects. But the effect of mouthguard was clearer in the distortion of the tooth and with steel ball. Considering the differences of mouthguards, the hard-insertion and the hard + space had significantly greater buffer capacity than conventional EVA. Furthermore, hard + space shows quite high shock absorption ability in the tooth distortion. Namely, hard + space has decreased the distortion of teeth up to several percentages in both impact objects.

Acceleration↗

Sex-related injury patterns among selected high school sports.

This cohort observational study was undertaken to test the hypothesis that the incidence of injuries for girls participating in high school sports is greater than that for boys. From 1995 through 1997, players were included in our study if they were listed on the school's varsity team roster for boys' or girls' basketball, boys' or girls' soccer, boys' baseball, or girls' softball. Injuries and opportunities for injury were recorded daily. Certified athletic trainers reported injury and exposure data. Based on 39,032 player-seasons and 8988 reported injuries, the injury rates per 100 players for softball (16.7) and for girls' soccer (26.7) were higher than for baseball (13.2) and boys' soccer (23.4). The knee injury rates per 100 players for girls' basketball (4.5) and girls' soccer (5.2) were higher than for their male counterparts. Major injuries occurred more often in girls' basketball (12.4%) and soccer (12.1%) than in boys' basketball (9.9%) and soccer (10.4%). Baseball players (12.5%) had more major injuries than softball players (7.8%). There was a higher number of surgeries, particularly knee and anterior cruciate ligament surgeries, for female basketball and soccer players than for boys or girls in other sports.

Adolescent↗

Autologous osteochondral mosaicplasty for capitellar osteochondritis dissecans in teenaged patients.

BACKGROUND: Autologous osteochondral mosaicplasty is a new technique to provide hyaline repair for articular defects. Although recent studies have reported the successful treatment of articular defects in the knee and ankle joints with this surgical procedure, little attention has been given to the surgical efficacy of mosaicplasty in the treatment of osteochondritis dissecans of the humeral capitellum. PURPOSE: To clarify the clinical outcomes of mosaicplasty for teenaged patients with advanced lesions of capitellar osteochondritis dissecans. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Eight teenaged patients with advanced lesions of capitellar osteochondritis dissecans underwent mosaicplasties. All patients were baseball players who were affected on the right side, which was also their throwing side. The surgical technique involves obtaining small-sized cylindrical osteochondral grafts from the lateral periphery of the femoral condyles and transplanting them to prepared osteochondral defects. At a mean follow-up of 24 months, all patients were evaluated clinically and radiographically. RESULTS: Seven of the 8 patients were free from elbow pain, and the remaining patient had mild pain occasionally. The mean clinical score described by Timmerman and Andrews (a maximum of 200 points) significantly improved from 140 points to 183 points postoperatively. All patients except one had excellent or good clinical results. Radiographically, the graft incorporation and a normal contour of the subchondral cortex were found in all patients. Magnetic resonance imaging showed that the preoperative heterogeneity of the lesion had disappeared and the signal intensity returned to normal. Six of the 8 patients, including all 3 pitchers, returned to competitive-level baseball. CONCLUSION: Mosaicplasty for advanced lesions of capitellar osteochondritis dissecans in teenaged baseball players can provide satisfactory clinical and radiographic results.

Adolescent↗

The modified docking procedure for elbow ulnar collateral ligament reconstruction: 2-year follow-up in elite throwers.

BACKGROUND: Ulnar collateral ligament injury is most common in the overhead-throwing athlete. Jobe et al published the first report of ulnar collateral ligament reconstruction in throwing athletes with a 62.5% success rate. Recently, Altchek developed a new docking technique for reconstruction of the ulnar collateral ligament. The authors report the first series using a further modification of the docking technique using a 4-strand palmaris longus graft for reconstruction of the ulnar collateral ligament. HYPOTHESIS: The modified docking technique yields a high rate of successful return to preinjury level of competition in elite baseball players. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: The authors retrospectively reviewed 25 elite professional or scholarship collegiate baseball players who underwent elbow ulnar collateral ligament reconstruction using the modified docking procedure with a minimum 2-year follow-up. RESULTS: Twenty-three of 25 (92%) were able to return to their preinjury levels of competition. The mean time to return was 11.5 months (range, 10-16 months). Complications included 1 transient postoperative ulnar nerve neurapraxia and 1 stress fracture of the ulnar bone bridge that occurred at 14 months postoperatively, after a full return to pitching. CONCLUSION: The modified docking technique yields highly successful return to preinjury level of competition rates (92%) in a select group of elite baseball players.

Adult↗

A comparative electromyographic analysis of the shoulder during pitching. Professional versus amateur pitchers.

Dynamic, fine-wire, intramuscular electromyography (EMG) was performed on 12 different shoulder muscles in 13 normal male subjects as they pitched a baseball. Seven were major league baseball pitchers and six were amateur pitchers. The act of pitching a fast ball was filmed at 450 frames per second with the EMG signals recorded synchronously. The subscapularis, supraspinatus, and infraspinatus muscles were tested in 13 subjects, the biceps brachii muscle was tested in 12, and other shoulder muscles were tested variously among the subjects. Two groups of muscles were identified. Group I muscles, the supraspinatus, infraspinatus, teres minor, deltoid, trapezius, and biceps brachii, served primarily to position the shoulder and elbow for the delivery of the pitch. These muscles were found to have greater activity during the early and late cooking stages, with less activity during acceleration. Group II muscles accelerated the arm and baseball forward in space. These muscles, the pectoralis major, serratus anterior, subscapularis, and latissimus dorsi, had stronger activity during the propulsive phase of the pitch. The professional pitchers were able to use the muscles about the shoulder in an efficient manner to achieve greater pitching velocities. The subscapularis and latissimus dorsi muscles of Group II had stronger activity among the professionals, whereas the supraspinatus, teres minor, and biceps brachii muscles of Group I had only minimal activity. The amateurs, on the other hand, continued to use all of the rotator cuff muscles and the biceps brachii muscle of Group I through the acceleration stage of the pitch.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Posterior ossification of the shoulder: the Bennett lesion. Etiology, diagnosis, and treatment.

We report a series of ossific lesions of the posterior inferior glenoid in a group of elite baseball players. We hope to clarify the etiology, diagnosis, and treatment of the Bennett lesion. From August 1985 to August 1991, we identified six professional baseball pitchers and one college pitcher with evidence of ossification of the shoulder on plain radiographs, computed tomography, or magnetic resonance imaging. Arthroscopic examination was performed in all cases. All seven players had identifiable posterior labral injury on arthroscopic examination; six of these seven also had varying degrees of undersurface posterior rotator cuff damage. No anterior tissue damage, anterior instability, or subacromial impingement was noted. No ossification was identified arthroscopically. Intraarticular labral and rotator cuff tears were debrided arthroscopically and patients underwent rehabilitation for 4 to 6 months after surgery. Six of the seven athletes returned to preinjury performance levels; however, one pitcher is no longer playing competitive baseball. The Bennett lesion is an extraarticular posterior ossification associated with posterior labral injury and posterior undersurface rotator cuff damage. It is not, however, a result of traction stresses in the region of the triceps insertion. Recognition is important for identification and treatment of the lesion and associated pathologic damage.

Adolescent↗

Little Leaguer's shoulder. A report of 23 cases.

Twenty-three cases of Little Leaguer's shoulder were reviewed including the history and physical examination findings, as well as bilateral internal and external rotation anteroposterior comparison radiographs of the proximal humerus. The average follow-up was 9.6 months (range, 1.5 to 54), and all patients were observed until they had either returned to baseball or their symptoms had resolved. The average age of the patients in this series was 14 years. The chief complaint in all patients was pain localizing to the proximal humerus during the act of throwing. The average duration of symptoms was 7.7 months. Nineteen patients (83%) were pitchers. Physical examination revealed tenderness to palpation over the proximal humerus in 20 patients (87%), with 16 (70%) demonstrating specific tenderness over the lateral aspect of the proximal humerus. Swelling, weakness, atrophy, and loss of motion were uncommon findings. All 23 patients demonstrated radiographic widening of the proximal humeral physis of the throwing arm on internal and external rotation comparison anteroposterior radiographs of the shoulder. All patients were treated with rest from baseball throwing for an average of 3 months. Twenty-one of the 23 patients (91%) returned to playing baseball and were asymptomatic. The classic radiographic finding of widening of the proximal humeral physis can easily be seen on bilateral anteroposterior internal and external rotation radiographs of the proximal humerus. Rest from throwing for at least 3 months is recommended, followed by a gradual return to throwing in an asymptomatic shoulder.

Adolescent↗

A comparison study of dynamic visual acuity between athletes and nonathletes.

A comparison study of dynamic visual acuity (DVA) was conducted using samples of nonathletic college students and college baseball players. The experimental population consisted of 17 male baseball players ranging in age from 19-24 years. The control population was made up of 25 male graduate students ranging in age from 23-29 years. Subjects reported the direction of a 20/25 "Landolt C" target exhibiting uniform angular motion produced by a projection system. Angular target velocities between 10 deg/sec and 110 deg/sec with an exposure time of 400 ms were used. The results showed a statistically significant difference between the two groups' DVA. The mean DVA for the baseball players was 82.35 deg/sec and 69.90 deg/sec for the control group.

Adult↗

Clinical profile and spectrum of commotio cordis.

CONTEXT: Although blunt, nonpenetrating chest blows causing sudden cardiac death (commotio cordis) are often associated with competitive sports, dangers implicit in such blows can extend into many other life activities. OBJECTIVE: To describe the comprehensive spectrum of commotio cordis events. DESIGN AND SETTING: Analysis of confirmed cases from the general community assembled in the US Commotio Cordis Registry occurring up to September 1, 2001. MAIN OUTCOME MEASURE: Commotio cordis event. RESULTS: Of 128 confirmed cases, 122 (95%) were in males and the mean (SD) age was 13.6 (8.2) years (median, 14 years; range, 3 months to 45 years); only 28 (22%) cases were aged 18 years or older. Commotio cordis events occurred most commonly during organized sporting events (79 [62%]), such as baseball, but 49 (38%) occurred as part of daily routine and recreational activities. Fatal blows were inflicted with a wide range of velocities but often occurred inadvertently and under circumstances not usually associated with risk for sudden death in informal settings near the home or playground. Twenty-two (28%) participants were wearing commercially available chest barriers, including 7 in whom the projectile made direct contact with protective padding (baseball catchers and lacrosse/hockey goalies), and 2 in whom the projectile was a baseball specifically designed to reduce risk. Only 21 (16%) individuals survived their event, with particularly prompt cardiopulmonary resuscitation/defibrillation (most commonly reversing ventricular fibrillation) the only identifiable factor associated with a favorable outcome. CONCLUSIONS: The expanded spectrum of commotio cordis illustrates the potential dangers implicit in striking the chest, regardless of the intent or force of the blow. These findings also suggest that the safety of young athletes will be enhanced by developing more effective preventive strategies (such as chest wall barriers) to achieve protection from ventricular fibrillation following precordial blows.

Adolescent↗

Effect of aerobic capacity on sweat rate and fluid intake during outdoor exercise in the heat.

We measured the aerobic capacity, sweat rate and fluid intake of trained athletes during outdoor exercise and examined the relationship between aerobic capacity and thermoregulatory responses at high ambient temperatures. The maximal aerobic capacity (VO2max) of the subjects, nine male baseball players of college age, was determined by maximal exercise tests on a cycle ergometer. The subjects practised baseball regularly without drinking fluids from 1330 to 1530 hours. After 30 min rest, they played a baseball game with free access to a sports drink at 15 degrees C from 1600 to 1830 hours. At a mean ambient temperature of 36.7 (SEM 0.2) degree C, the mean percentage of body mass loss (delta mb) and increase of oral temperature (delta To) from 1330 to 1530 hours was 3.47 (SEM 0.12)% and 0.81 (SEM 0.14) degree C, respectively. The sweat loss from 1330 to 1830 hours was 56.53 (SEM 1.56)ml.kg-1 of body mass (mb) while the mean fluid consumption was 44.78 (SEM 2.39)ml.kg-1 of mb, with recovery of 76.08 (SEM 2.81)% of sweat loss. The VO2max was significantly inversely correlated with delta mb, fluid intake and rehydration amount, but showed no correlation with delta To. These results would suggest that at a given exercise intensity in subjects with a higher aerobic capacity body temperature is maintained with a lower sweating rate than that in subjects with a lower aerobic capacity.

Adult↗

Influence of sports discipline on shoulder rotator cuff balance.

Isokinetic shoulder rotational strength was evaluated in four groups of subjects as follows: 12 nonathletes, 12 runners, 15 tennis players, and 12 baseball players for a total of 51 subjects. The tests were performed in the seated 45 degrees abducted test position in the scapular plane at 60, 180, and 300 degrees.s-1 for both shoulders. Peak torque and mean power values were gathered, and from these values the internal/external rotation ratios were calculated. Intergroup comparison showed a progression of the ratio related to the sports discipline. The nonathletes and runners had ratios close to those reported for nonathletes (1.3 to 1.5). The tennis players had ratios close to 1.5, whereas the baseball players had ratios from 1.6 to 2.2. The comparison between dominant and nondominant side showed no significant differences in the tennis players and higher values for the dominant side in the nonathletes and runners under certain conditions (180 degrees.s-1 for the nonathletes and 300 degrees.s-1 for the runners). Regarding the baseball players, the ratio was systematically higher for the dominant side. These results raise questions about the influence of sports discipline on the internal/external rotator muscle ratio and indicate the need to establish normative values based on the characteristics of the population under study.

Adult↗

Echolocating bats use a nearly time-optimal strategy to intercept prey.

Acquisition of food in many animal species depends on the pursuit and capture of moving prey. Among modern humans, the pursuit and interception of moving targets plays a central role in a variety of sports, such as tennis, football, Frisbee, and baseball. Studies of target pursuit in animals, ranging from dragonflies to fish and dogs to humans, have suggested that they all use a constant bearing (CB) strategy to pursue prey or other moving targets. CB is best known as the interception strategy employed by baseball outfielders to catch ballistic fly balls. CB is a time-optimal solution to catch targets moving along a straight line, or in a predictable fashion--such as a ballistic baseball, or a piece of food sinking in water. Many animals, however, have to capture prey that may make evasive and unpredictable maneuvers. Is CB an optimum solution to pursuing erratically moving targets? Do animals faced with such erratic prey also use CB? In this paper, we address these questions by studying prey capture in an insectivorous echolocating bat. Echolocating bats rely on sonar to pursue and capture flying insects. The bat's prey may emerge from foliage for a brief time, fly in erratic three-dimensional paths before returning to cover. Bats typically take less than one second to detect, localize and capture such insects. We used high speed stereo infra-red videography to study the three dimensional flight paths of the big brown bat, Eptesicus fuscus, as it chased erratically moving insects in a dark laboratory flight room. We quantified the bat's complex pursuit trajectories using a simple delay differential equation. Our analysis of the pursuit trajectories suggests that bats use a constant absolute target direction strategy during pursuit. We show mathematically that, unlike CB, this approach minimizes the time it takes for a pursuer to intercept an unpredictably moving target. Interestingly, the bat's behavior is similar to the interception strategy implemented in some guided missiles. We suggest that the time-optimal strategy adopted by the bat is in response to the evolutionary pressures of having to capture erratic and fast moving insects.

Animals↗

Recruits from other industries. What can they teach you?. Interview by John McCormack.

When Michael Jordan traded in his high-tops for cleats, people had their doubts. What skills could this high-flying king of the court bring to the baseball diamond? Ask the players for the Birmingham Barons, the minor league team that he joined last year. Jordan didn't bring sophisticated baseball skills to the organization, but he was able to teach his new peers--all lifelong baseball players--about physical conditioning, competitiveness, mental preparation, and the ups and downs of fame. When materials managers from other industries sign on to a hospital team, there may be doubts about whether their skills are transferable. But, like Jordan, they bring to the team unique experiences and perspectives that can enhance the game. Hospitals that hire managers from other disciplines often find that these people bring bold new ideas to the organization. Their special skills could even help improve the performance of longtime players in the health care arena. We recently spoke with four hospital managers who immigrated to health care from other industries. Read their stories and you, too, might see your job in a whole new way.

Career Mobility↗

Functional multijoint position reproduction acuity in overhead-throwing athletes.

CONTEXT: Baseball players rely on the sensorimotor system to uphold the balance between upper extremity stability and mobility while maintaining athletic performance. However, few researchers have studied functional multijoint measures of sensorimotor acuity in overhead-throwing athletes. OBJECTIVE: To compare sensorimotor acuity between 2 high-demand functional positions and among planes of motion within individual joints and to describe a novel method of measuring sensorimotor function. DESIGN: Single-session, repeated-measures design. SETTING: University musculoskeletal research laboratory. PATIENTS OR OTHER PARTICIPANTS: Twenty-one National Collegiate Athletic Association Division I baseball players (age = 20.8 +/- 1.5 years, height = 181.3 +/- 5.1 cm, mass = 87.8 +/- 9.1 kg) with no history of upper extremity injury or central nervous system disorder. MAIN OUTCOME MEASURE(S): We measured active multijoint position reproduction acuity in multiple planes using an electromagnetic tracking device. Subjects reproduced 2 positions: arm cock and ball release. We calculated absolute and variable error for individual motions at the scapulothoracic, glenohumeral, elbow, and wrist joints and calculated overall joint acuity with 3-dimensional variable error. RESULTS: Acuity was significantly better in the arm-cock position compared with ball release at the scapulothoracic and glenohumeral joints. We observed significant differences among planes of motion within the scapulothoracic and glenohumeral joints at ball release. Scapulothoracic internal rotation and glenohumeral horizontal abduction and rotation displayed less acuity than other motions. CONCLUSIONS: We established the reliability of a functional measure of upper extremity sensorimotor system acuity in baseball players. Using this technique, we observed differences in acuity between 2 test positions and among planes of motion within the glenohumeral and scapulothoracic joints. Clinicians may consider these differences when designing and implementing sensorimotor system training. Our error scores are similar in magnitude to those reported using single-joint and single-plane measures. However, 3-dimensional, multijoint measures allow practical, unconstrained test positions and offer additional insight into the upper extremity as a functional unit.

Journal Article↗

Medial instability of the elbow in throwing athletes. Treatment by repair or reconstruction of the ulnar collateral ligament.

From September 1974 to December 1987, seventy-one patients were operated on for valgus instability of the elbow. The average length of follow-up of sixty-eight patients (seventy operations) was 6.3 years (range, two to fifteen years). At the operation, a torn or incompetent ulnar collateral ligament was found. Fourteen patients had a direct repair of the ligament, and fifty-six had a reconstruction of the ligament using a free tendon graft. The result was excellent or good in ten patients in the repair group and in forty-five (80 per cent) in the reconstruction group. Seven of the fourteen patients who had a direct repair returned to the previous level of participation in their sport. Of the fifty-six who had a reconstruction, thirty-eight (68 per cent) returned to the previous level of participation. Twelve of the sixteen major-league baseball players who had a reconstruction as the primary operation (no previous operation on the elbow) were able to return to playing major-league baseball, and two of the seven major-league players who had a direct repair returned to playing major-league baseball. Previous operations on the elbow decreased the chance of returning to the previous level of sports participation (p = 0.04). Fifteen patients had postoperative ulnar neuropathy. This was transient in six patients, only one of whom was unable to return to the previous level of sport. The other nine patients had an additional operation for the neuropathy; four were able to return to the previous level of sport.

Adult↗

Comparison of bone mineral density between athletic and non-athletic Chinese male adolescents.

For the evaluation of the effect of exercise on bone mineral density of adolescent athletes, twenty-nine Chinese male adolescent athletes, each of whom had regular training in his major sport which included baseball, swimming, judo and middle/long-distance running for one to six years and eight age-matched non-athletic controls were included in this study. Bone mineral density (BMD) was measured in all study subjects using dual photo absorptiometry at the second to fourth lumbar spines (L2-4) and the right femoral neck (FN). The results revealed the following: (1) the combined group of athletes had significantly greater BMD of L2-4 (1.08 +/- 0.09 g/cm2) than the control group (0.99 +/- 0.08 g/cm2) and a tendency for greater BMD of FN (1.15 +/- 0.13 g/cm2) than the control group (1.09 +/- 0.13 g/cm2); (2) judo majors had significantly greater BMD of L2-4 than baseball majors (P < 0.05), swimming majors (P < 0.01), track majors (P < 0.05) and controls (P < 0.005); (3) baseball majors had significantly greater BMD of L2-4 than controls (P < 0.05) and greater BMD of FN than swimming majors (P < 0.05), judo majors (P < 0.05), track majors (P < 0.005) and controls (P < 0.005); (4) body weight and body mass index (BMI) had good correlation with BMD of L2-4 and FN in control group, (5) in the combined group of athletes, weight and BMI were only strongly linked to BMD of FN, and not to BMD of L2-4. There was no good correlation between BMI and BMD of L2-4 and FN in any group of athletes. We concluded that (1) physical activity during adolescence may contribute significantly towards increasing BMD of athletes and (2) the training type may provide a specific stimulus for increasing BMD at specific localized sites experienced in training.

Adolescent↗

Thoracic outlet syndrome in a throwing athlete diagnosed with MRI and MRA.

Thoracic outlet syndrome comprises the clinical manifestations in the arm caused by compression of the neurovascular bundle as it leaves the thoracic inlet. The neurovascular bundle is composed of the subclavian artery, the subclavian vein, and the brachial plexus. The symptoms of thoracic outlet or inlet syndrome are most often caused by compression of the nerves of the brachial plexus, which is involved in up to 98% of cases; the remainder are due to vascular compression. MRI with MRA demonstrates well the anatomy of the brachial plexus as well as any vascular compression or occlusion. The relationship of the axillary and subclavian vein to the first rib and subclavius muscle also can be demonstrated. We present a college baseball player who presented with numbness in the fingers of his throwing hand when throwing a baseball. Evaluation with spin-echo and two-dimensional time-of-flight MR angiographic (MRA) imaging of the thoracic outlet region revealed obstruction of the subclavian vein with the arm abducted. To our knowledge, no such cases have been diagnosed previously with MRI.

Adult↗