A Nation-Wide Survey of High School Baseball Coaches' Perceptions Indicates their Arm Care Programs Play a Role in Injury Prevention.

BACKGROUND: Arm care programs consisting of upper extremity strengthening and stretching have been recommended for injury prevention for pitchers of all ages. There has been no investigation into high school baseball coaches' usage and perceptions of arm care programs to mitigate physical impairments associated with injuries in baseball players. HYPOTHESIS/PURPOSE: The purpose of this study was to investigate the current usage of arm care programs by high school baseball coaches. The primary objective was to determine if coaches use group-based or individualized arm care programs. The secondary objective sought to determine if the use of arm care programs is influenced by coaches' age, education, and experience level. Finally, this study explored the potential barriers to arm care implementation and high school baseball coaches' current awareness and beliefs of injury prevention. STUDY DESIGN: Descriptive cross-sectional survey. METHODS: A 29-item online survey was emailed to 18,500 high school baseball coaches throughout the United States. Data were collected for three months, and the response rate was 3.7%. RESULTS: A total of 87.3% (n=571/654) of responding coaches use arm care programs with their players. Of coaches performing arm care, only 18.5% of 571 individualize their arm care exercises based on specific player needs. However, older and more experienced coaches are more likely to individualize their programs. Among the 12.7% (n=83/654) of coaches who do not use arm care programs, the two most commonly cited reasons for not implementing arm care were lack of observed benefit (41%) and insufficient staff (31%). Although 42% of 654 coaches recognized reduced shoulder mobility as a major contributor to injury, risk factors such as throwing with a fatigued arm, previous injury history, and throwing > 8 months per year were not consistently identified as primary risk factors. CONCLUSION: The results of this study suggest that the majority high school baseball coaches implement group-based arm care exercise programs to prevent injury. Lack of confidence in the effectiveness and staffing limitations were major barriers to implementation of arm care programming. However, the responding coaches exhibited inconsistent risk factor awareness and dated injury prevention beliefs. Therefore, better educational collaboration between rehabilitation professionals and high school coaches regarding injury risk factors and preventative strategies is warranted. LEVEL OF EVIDENCE: Level 3.

Interfascicular matrix-mediated transverse deformation and sliding of discontinuous tendon subcomponents control the viscoelasticity and failure of tendons.

In the present article, we investigated the sliding of discontinuous tendon subcomponents and the variation of nonhomogeneous deformation in the human Achilles tendon (AT) over time using uniaxial tensile and relaxation tests. The deformation and the resulting strain distribution under uniaxial tension are examined using a vision-based 3-D digital image correlation (DIC) system, which allows estimation of the strain field in the axial and lateral directions. Relaxation test under B-mode ultrasound imaging with the use of DIC method provides information about the local strain variation over time in the axial and anteroposterior directions. The observed nonhomogeneous deformation, a result from the twisted structure of the tendon, shows both compressive and tensile transverse strains that can generate interfascicular matrix (IFM) failure and initiate water accumulation in the course of tendinopathy. Moreover, using B-mode elastography with the DIC method, we have observed areas of low stiffness when the strain values exceed the strength limits, and this could correspond to IFM carrying the load between discontinuous tendon subcomponents. Thus, IFM carrying complex multiscale stresses may be responsible for the strength and viscoelastic properties of the AT. The results presented here reveal a new pathomechanism of AT failure. This could be useful in further studies on tendinopathy as well as effective planning of the AT therapy.

Influence of density and environmental factors on decomposition kinetics of amorphous polylactide - Reactive molecular dynamics studies.

In this work, we investigate the influence of the surrounding environment and the initial density on the decomposition kinetics of polylactide (PLA). The decomposition of the amorphous PLA was investigated by means of reactive molecular dynamics simulations. A computational model simulates the decomposition of PLA polymer inside the bulk, due to the assumed lack of removal of reaction products from the polymer matrix. We tracked the temperature dependency of the water and carbon monoxide production to extract the activation energy of thermal decomposition of PLA. We found that an increased density results in decreased activation energy of decomposition by about 50%. Moreover, initiation of decomposition of the amorphous PLA is followed by a rapid decline in activation energy caused by reaction products which accelerates the hydrolysis of esters. The addition of water molecules decreases initial energy of activation as well as accelerates the decomposition process. Additionally, we have investigated the dependency of density on external loading. Comparison of pressures needed to obtain assumed densities shows that this relationship is bilinear and the slope changes around a density equal to 1.3g/cm(3). The conducted analyses provide an insight into the thermal decomposition process of the amorphous phase of PLA, which is particularly susceptible to decomposition in amorphous and semi-crystalline PLA polymers.

Rescaled Local Interaction Simulation Approach for Shear Wave Propagation Modelling in Magnetic Resonance Elastography.

Properties of soft biological tissues are increasingly used in medical diagnosis to detect various abnormalities, for example, in liver fibrosis or breast tumors. It is well known that mechanical stiffness of human organs can be obtained from organ responses to shear stress waves through Magnetic Resonance Elastography. The Local Interaction Simulation Approach is proposed for effective modelling of shear wave propagation in soft tissues. The results are validated using experimental data from Magnetic Resonance Elastography. These results show the potential of the method for shear wave propagation modelling in soft tissues. The major advantage of the proposed approach is a significant reduction of computational effort.

Ultrasonographic evaluation of splenic enlargement in athletes with acute infectious mononucleosis.

OBJECTIVE: To quantitatively assess the degree and rate of splenic enlargement and the time required for regression of splenic enlargement in collegiate athletes diagnosed with acute infectious mononucleosis (IM). DESIGN: Prospective cohort study. SETTING: Academic Medical Center(s) outpatient sports medicine clinic. STUDY PARTICIPANTS: Volunteer Division I University athletes. INTERVENTIONS: A limited abdominal ultrasound was performed on each participant by a licensed and experienced ultrasonographer. Splenic measurements were taken to assess maximum splenic length. Athletes who were subsequently diagnosed with infectious mononucleosis (clinical illness and a positive monospot) underwent serial splenic ultrasounds and physical exams (weekly) until resolution of clinical symptoms and splenic enlargement (as determined by ultrasound measurements). MAIN OUTCOME MEASURES: Per cent enlargement of spleen size (length) from baseline. Time (in days) from onset of clinical illness to maximum splenic length. Time (in days) required for resolution of splenic enlargement. RESULTS: 20 subjects were diagnosed with acute IM during a 5 year time period. Maximum splenic length increased a mean of 33.6% (SD 19.9%) from baseline values. Peak splenic enlargement was reached a mean of 12.3 (SD 5.1) days from onset of clinical illness. A linear model demonstrated that spleen size decreases approximately 1% per day after reaching peak splenic enlargement. CONCLUSIONS: The majority of athletes with IM experience a moderate degree of splenomegaly. Peak splenic enlargement occurs within 2 weeks from the time of symptom onset in most cases, but may extend to 3.5 weeks. The rate of splenic enlargement appears to be predictable for an individual who develops IM. Ultrasonographic data further show that splenomegaly associated with acute IM infection resolves within 4-6 weeks of symptom onset in the majority of cases.

Gabapentin suppresses spasticity in the spinal cord-injured rat.

UNLABELLED: Spasticity poses a major detrimental impact on the quality of life in a significant number of people with spinal cord injury (SCI). Recent observations in our laboratory suggest that spinal transection at the sacral S(2) level induces a significant increase in glutamatergic input to sacrocaudal motoneurons during the time spasticity is present in the tail muscles. The present study examined the efficacy of gabapentin, an agent that has been shown to reduce glutamate release, in managing spasticity within the tail musculature. METHOD: In this blinded, crossover study adult Sprague-Dawley rats with S(2) spinal transections were tested behaviorally for the progression of spasticity in the tail musculature using our established system. When the animals demonstrated a significant level of spastic behavior (e.g. increased response to quick stretch, noxious and non-noxious cutaneous stimuli), they received either saline or the antiepileptic agent gabapentin (GBP; 50 mg/kg i.p.) and were assessed behaviorally and electrophysiologically at 1, 3, 6, 12 and 24 h post-injection. RESULTS: Both spastic behavior and electromyography (EMG) activity were significantly decreased at 1 and 3 h post-GBP injection when compared with the activity level following administration of saline. Spastic behavior and EMG activity gradually increased over time and returned to baseline activity by 24 h post-injection. CONCLUSION: Gabapentin diminishes both the behavioral and electrophysiological manifestation of SCI-induced spasticity, in the tail musculature, in a time dependent manner.

Rehabilitation concepts and supportive devices for overuse injuries of the upper extremities.

Rehabilitation of overuse injuries requires the health care professional to understand normal and common pathologic mechanics of the patient's sport or physical activity. Evaluation of the total mechanics of the body, not just the local area presenting with discomfort, is important. [figure: see text] The cause of the presenting injury can be a dysfunction at a distant site. Rest and supportive devices are helpful in allowing the athlete to return to a normal activity level. A progressive reconditioning program needs to address strength and flexibility issues and endurance and eccentric exercises.

Management of ankle sprains.

Without adequate care, acute ankle trauma can result in chronic joint instability. Use of a standardized protocol enhances the management of ankle sprains. In patients with grades I or II sprains, emphasis should be placed on accurate diagnosis, early use of RICE (rest, ice, compression and elevation), maintenance of range of motion and use of an ankle support. Sprains with complete ligament [corrected] tears (grade III) may require surgical intervention. Although early motion and mobility are recommended, ligamentous strength does not return until months after an ankle sprain.

Shoulder rehabilitation strategies, guidelines, and practice.

This framework for rehabilitation is consistent with the proximal-to-distal kinetic chain biomechanical model and applies current concepts of motor control and closed chain exercises. This framework approaches the final goal--glenohumeral motion and function-through facilitation by scapular control, and scapular control through facilitation by hip and trunk activation. This article supplies guidelines for rehabilitation and practices to implement the guidelines that have proved effective in our hands. Other protocols may be effective, as long as they adhere to several basic concepts of kinetic chain-based shoulder rehabilitation: 1. Functional shoulder rehabilitation requires that the muscle activations and joint motions follow a proximal-to-distal pathway along the appropriate kinetic chain. 2. Muscles around the shoulder function in an integrated fashion and should be rehabilitated in integrated patterns. Specific muscles may need isolated activation, but this activation should be facilitated by placing the proximal segments in a facilitating function. 3. Scapular control and coupled rotator cuff activation is vital to normal shoulder function. 4. Closed chain axial loading exercises are the primary means of early shoulder rehabilitation and are the mainstays of functional rehabilitation protocols.

A review of articular cartilage pathology and the use of glucosamine sulfate.

OBJECTIVE: To refresh the athletic trainer's knowledge of articular cartilage biomechanics, physiology, and structure and explore the role of glucosamine sulfate in treating articular cartilage pathologic conditions, including supplementation methods and clinical outcomes. DATA SOURCES: We searched MEDLINE from 1989 through 2000 and SPORT Discus from 1975 through 2000 using the following key words: glucosamine sulfate, articular cartilage, osteoarthritis, and proteoglycans. DATA SYNTHESIS: Articular cartilage functions as a wear-resistant, smooth, nearly frictionless, load-bearing surface. Glucosamine sulfate can be thought of as a building block that helps restore the proteoglycan-rich extracellular matrix and thus balance articular cartilage catabolism and anabolism. Beneficial clinical effects of glucosamine sulfate in the osteoarthritic population have been documented. However, the use of glucosamine sulfate for athletic articular cartilage injuries is unproved. CONCLUSIONS/RECOMMENDATIONS: Clinical studies indicate that glucosamine sulfate has been shown to be a safe and relatively effective treatment for osteoarthritis. However, no evidence to date supports or refutes a carryover effect to the athletic population and the injuries that occur in sport.

Rehabilitation after posterolateral dislocation of the elbow in a collegiate football player: a case report.

OBJECTIVE: To describe a functional rehabilitation program for a football player with a grade 2 posterolateral elbow dislocation to facilitate early return to competition. BACKGROUND: Conservative management of a posterior dislocation of the elbow is common. The elbow is the second most frequently dislocated large joint in adults. Two common mechanisms of dislocation are hyperextension and posterolateral rotation. Prolonged immobilization can be detrimental to regaining full range of motion and function of the elbow, whereas early directed rehabilitation may lead to early return to normal function. DIFFERENTIAL DIAGNOSIS: Elbow dislocation with medial collateral ligament rupture, elbow subluxation, elbow dislocation with neurovascular compromise, or supracondylar fracture. TREATMENT: The athlete received immediate care of reduction and immobilization in a 90 degrees posterior splint followed by a radiologic evaluation. Postreduction treatment included a short immobilization period and early initiation of protected active and resistive range-of-motion exercises. The athlete was able to return to full football activities in 3 weeks. He competed for the rest of the season with the elbow braced and taped, with no recurring incidents of instability. UNIQUENESS: The time to return to full participation was rapid. The medial collateral ligament was intact, as determined by magnetic resonance imaging. The athlete has since been followed for 2 football seasons and has not demonstrated any detrimental effects due to his early return. CONCLUSIONS: Early determination of the status of the medial collateral ligament through physical examination or imaging combined with early directed rehabilitation of a posterolateral elbow instability enabled this athlete to respond well. He regained pain-free full range of motion, strength, and function, allowing full participation in football at the Division I level with no recurring incidence of dislocation.

A kinetic chain approach for shoulder rehabilitation.

OBJECTIVE: To introduce an approach to shoulder rehabilitation that integrates the kinetic chain throughout the rehabilitation program while providing the theoretical rationale for this program. BACKGROUND: The focus of a typical rehabilitation program is to identify and treat the involved structures. However, in activities of sport and daily life, the body does not operate in isolated segments but rather works as a dynamic unit. Recently, rehabilitation programs have emphasized closed kinetic chain exercises, core-stabilization exercises, and functional programs. These components are implemented as distinct entities and are used toward the end of the rehabilitation program. DESCRIPTION: Kinetic chain shoulder rehabilitation incorporates the kinetic link biomechanical model and proximal-to-distal motor-activation patterns with proprioceptive neuromuscular facilitation and closed kinetic chain exercise techniques. This approach focuses on movement patterns rather than isolated muscle exercises. Patterns sequentially use the leg, trunk, and scapular musculature to activate weakened shoulder musculature, gain active range of motion, and increase strength. The paradigm of kinetic chain shoulder rehabilitation suggests that functional movement patterns and closed kinetic chain exercises should be incorporated throughout the rehabilitation process. CLINICAL ADVANTAGES: The exercises in this approach are consistent with biomechanical models, apply biomechanical and motor control theory, and work toward sport specificity. The exercises are designed to stimulate weakened tissue by motion and force production in the adjacent kinetic link segments.

Online detection of REM sleep based on the comprehensive evaluation of short adjacent EEG segments by artificial neural networks.

1. For scientific and clinical requirements the present objective is a robust automatic online algorithm to detect rapid eye movement (REM) sleep from single channel sleep EEG data without using EMG or EOG information. 2. For data preprocessing 20 seconds time periods of the continuous EEG activity are digitally filtered in 7 frequency bands. Then the RMS values of these filtered signals are calculated along segments of 2.5 seconds. The resulting matrix of RMS values is representing information on the power of the signal localized in time and frequency and serves as input to an artificial neural network. A pooled set of EEG data together with the corresponding manual evaluation of the recordings was used in the training process. 3. Afterwards more than 90% of the time periods not belonging to the training set could be correctly labeled into REM and nonREM periods. In comparison to an older algorithm based on RMS values calculated along segments of 20 seconds, the error rate could be reduced by 20%.

Arthroscopically treated tears of the glenoid labrum. Factors influencing outcome.

Labral tears and associated glenohumeral ligament injuries were classified and treated arthroscopically in 83 patients. Transverse labral tears were the most common. Subtle increased glenohumeral translation was noted in 24% of patients. Glenohumeral ligament injury was present in 58% of the shoulders, with the middle and superior ligaments or middle ligaments alone most commonly involved. These ligament injuries were classified into different groups based on severity. Partial excision of the torn labrum was the primary treatment in all patients and was combined with glenohumeral ligament repair in 9 patients. Seventy-eight patients were available for subjective follow-up evaluation (average, 3.2 years), while 53 patients were objectively evaluated (average followup, 2.8 years). There were 14% excellent, 71% satisfactory, and 15% poor results. The main factor associated with poor results was a grade III glenohumeral ligament injury in which only partial excision of the torn labrum was performed. There was a positive correlation between injury to both the superior and middle glenohumeral ligaments and increased anterior translation demonstrated by preoperative stability testing at 60 degrees of humeral abduction in neutral rotation. We believe glenohumeral ligament injury is often associated with labral tears and arthroscopic partial labral excision is only effective in those patients who have grade I or II (less severe) glenohumeral ligament injuries.

[Knowledge of acceptance and use of preventive measures in Germany]. / Wissensstand, Akzeptanz und Anwendung von Prophylaxemassnahmen in Deutschland.

Important aspects of hygienic behaviour and patient compliance were investigated in a written survey of 500 adults. The results indicate a clear discrepancy between behaviour considered necessary by dentists and what people actually do, with reference both to thorough and methodical dental hygiene at home and knowledge of appropriate prophylactic measures. It was also seen that adults were only minimally willing to accept suggestions for improvement in their behaviour in these respects and that they were insufficiently motivated to change behaviour and habits.

Flexibility comparisons of junior elite tennis players to other athletes.

Flexibility measurements were obtained in 86 junior elite tennis players and compared to the flexibility measurements of 139 athletes involved in other sports. The measurements obtained included sit and reach flexibility, quadricep flexibility, hamstring flexibility, gastrocnemius flexibility, shoulder internal rotation, and shoulder external rotation. All measurements except sit and reach flexibility were obtained goniometrically. Tennis players were significantly tighter in sit and reach flexibility, dominant shoulder internal rotation, and nondominant shoulder internal rotation. They were significantly more flexible in dominant shoulder external rotation and nondominant shoulder external rotation. The flexibility differences found in tennis players suggest adaptations to the musculoskeletal demands of their sport. These results suggest that a sport-specific flexibility program may be necessary for junior elite tennis players in order to promote maximum performance and help prevent flexibility-related injuries.

Use of an orthotic device in the treatment of posterior heel pain.

Research Funded by the Lexington Clinic Foundation for Research and Education. Posterior heel pain (PHP) presents a difficult clinical challenge. The causes of PHP include Haglund syndrome (pump bump deformity), Achilles tendinitis, and Sever's disease (retrocalcaneal bursitis, traction apophysitis). The purposes of this study were to 1) describe a new orthotic device used in the treatment of PHP and 2) evaluate the effectiveness of this device. The orthotic device consisted of a neoprene sleeve holding 1/4 inch PPT foam rubber horseshoe (Sports Supports, Inc., Dallas, TX). The horseshoe was placed directly over the injury to protect and relieve pressure or was inverted and used as a counterforce brace to reduce the tensile stress to the Achilles tendon. Eight patients (6 children, 2 adults) were evaluated at the time of application and after 1 month of use. Three criteria were considered: 1) subjective pain scale, 2) active goniometric measurements, and 3) toe raise test. The statistical analysis indicated a significant improvement in pain during activity from initial to follow-up and in pain after activity from initial to follow-up. All patients demonstrated improved strength and flexibility. It was concluded that this device may be an effective adjunct to the treatment of PHP. J Orthop Sports Phys Ther 1990;11(9):410-413.

A musculoskeletal approach to the preparticipation physical examination. Preventing injury and improving performance.

Preparticipation physical examinations provide information concerning an athlete's ability to participate safely in sports. By collecting information specific to the musculoskeletal system in addition to that from a general medical examination, information can be gained that may improve performance and help prevent certain injuries. Two thousand one hundred seven athletes from a variety of sports from the junior high to the college level were examined using specific tests for flexibility, strength, and endurance. Females were significantly more flexible than were males on all flexibility measurements, and males were significantly stronger than were females on all strength measurements. Upper-body athletes were tighter in dominant side internal rotation and significantly looser in dominant side external rotation. Lower-body athletes, especially females, were significantly tighter in the leg muscles. These results indicate that the adaptations of the musculo-skeletal system are sport specific and depend on the body area that is placed under stress.

Isokinetic peak torque and work values for the shoulder.

The purposes of this study were to: a) measure peak torque (PKT) at 60 and 180 degrees /sec of angular velocity and work data at 180 degrees /sec of angular velocity for isokinetic muscular performance during external/internal rotation (ER/IR) and modified abduction/adduction (MOD-AB/AD) tests, b) compare the dominant and nondominant upper extremity data, and c) compare the relative peak torque between sexes. Twenty-one males and 20 females were tested isokinetically at 60 and 180 degrees /sec in MOD-AB/AD and ER/IR. A significant difference did not exist between the dominant and nondominant shoulders for the PKT. A significant difference did exist between sexes when comparing PKT, total work, and power but not when comparing endurance and agonist/antagonist PKT and work ratios. The data described demonstrated large standard deviations suggesting the need for specific categorization of persons to establish normative values. J Orthop Sports Phys Ther 1989;10(7):264-269.