Showing papers in "Journal of Athletic Training in 2001"

The Neurometabolic Cascade of Concussion

Abstract: OBJECTIVE: To review the underlying pathophysiologic processes of concussive brain injury and relate these neurometabolic changes to clinical sports-related issues such as injury to the developing brain, overuse injury, and repeated concussion DATA SOURCES: Over 100 articles from both basic science and clinical medical literature selected for relevance to concussive brain injury, postinjury pathophysiology, and recovery of function DATA SYNTHESIS: The primary elements of the pathophysiologic cascade following concussive brain injury include abrupt neuronal depolarization, release of excitatory neurotransmitters, ionic shifts, changes in glucose metabolism, altered cerebral blood flow, and impaired axonal function These alterations can be correlated with periods of postconcussion vulnerability and with neurobehavioral abnormalities While the time course of these changes is well understood in experimental animal models, it is only beginning to be characterized following human concussion CONCLUSIONS/RECOMMENDATIONS: Following concussion, cerebral pathophysiology can be adversely affected for days in animals and weeks in humans Significant changes in cerebral glucose metabolism can exist even in head-injured patients with normal Glasgow Coma Scores, underscoring the need for in-depth clinical assessment in an effort to uncover neurocognitive correlates of altered cerebral physiology Improved guidelines for clinical management of concussion may be formulated as the functional significance and duration of these postinjury neurometabolic derangements are better delineated

Postural Stability and Neuropsychological Deficits After Concussion in Collegiate Athletes.

Abstract: OBJECTIVE: Postural stability and neuropsychological testing are gradually becoming integral parts of postconcussion assessment in athletes. Clinicians, however, sometimes question the viability of instituting preseason baseline testing and the value of these results in making return-to-play decisions. Our purpose was to examine the course of recovery on various postural stability and neuropsychological measures after sport-related concussion. A secondary goal was to determine if loss of consciousness and amnesia, both of which are heavily weighted in most of the concussion classification systems, affect the rate of recovery. DESIGN AND SETTING: All subjects underwent a battery of baseline postural stability and neuropsychological tests before the start of their respective seasons. Any athletes subsequently injured were followed up at postinjury days 1, 3, and 5. Matched control subjects were assessed using the same test battery at the same time intervals. SUBJECTS: We studied 36 Division I collegiate athletes who sustained a concussion and 36 matched control subjects. MEASUREMENTS: We assessed postural stability using the Sensory Organization Test on the NeuroCom Smart Balance Master System and the Balance Error Scoring System. Neurocognitive functioning was measured with several neuropsychological tests: Trail-Making Test, Wechsler Digit Span Test, Stroop Color Word Test, and Hopkins Verbal Learning Test. RESULTS: Injured subjects demonstrated postural stability deficits, as measured on both the Sensory Organization Test and Balance Error Scoring System. These deficits were significantly worse than both preseason scores and matched control subjects' scores on postinjury day 1. Only the results on the Trail-Making Test B and Wechsler Digit Span Test Backward resulted in a logical recovery curve that could explain lowered neuropsychological performance due to concussive injury. Significant differences were revealed between the control and injured groups at day 1 postinjury, but a significant decline between baseline and postinjury scores was not demonstrated. Loss of consciousness and amnesia were not associated with increased deficits or slowed recovery on measures of postural stability or neurocognitive functioning. CONCLUSIONS: Athletes with cerebral concussion demonstrated acute balance deficits, which are likely the result of not using information from the vestibular and visual systems effectively. Neurocognitive deficits are more difficult to identify in the acute stages of concussion, although concentration, working memory, immediate memory recall, and rapid visual processing appear to be mildly affected. More research is necessary to determine the best neuropsychological test battery for assessing sport-related concussion.

Posttraumatic Retrograde and Anterograde Amnesia: Pathophysiology and Implications in Grading and Safe Return to Play.

Abstract: OBJECTIVE: The presence of posttraumatic amnesia (PTA) and loss of consciousness have been main factors used in a number of concussion guidelines. In this article, the focus is on using PTA (both retrograde and anterograde) as salient indicators of traumatic brain injury severity and the most reliable index of outcome prediction, even in mild cases. DATA SOURCES: A MEDLINE search for the years 1990-2000 using the key words posttraumatic retrograde and anterograde amnesia, concussion and mild traumatic brain injury was done. DATA SYNTHESIS: On-the-field testing of PTA is a salient and integral component of the initial and follow-up neurologic assessments of the head-injured athlete. CONCLUSIONS/RECOMMENDATIONS: Initial and follow-up assessments of PTA, anterograde and retrograde, are an essential part of the neurologic evaluation of the head-injured athlete. Increasingly, neuropsychological testing, including computer models, is being employed in this assessment. The importance of not just PTA but all postconcussion signs and symptoms being absent at rest and exertion before allowing the athlete to return to play is emphasized.

Standardized Mental Status Testing on the Sideline After Sport-Related Concussion.

Abstract: OBJECTIVE: The effects of concussion on mental status are often difficult to assess on routine clinical examination. I investigated the efficacy of standardized mental status testing on the sport sideline to detect abnormalities that result from concussion and provide an objective measure of postinjury cognitive recovery. DESIGN AND SETTING: All subjects underwent a standardized preseason baseline mental status evaluation. Standardized testing of injured and uninjured control subjects was repeated on the sideline immediately after concussion and 48 hours after injury. SUBJECTS: Sixty-three high school and collegiate football players with concussion and 55 uninjured control subjects were studied. MEASUREMENTS: The Standardized Assessment of Concussion (SAC) was administered to evaluate neurocognitive functioning and neurologic status. RESULTS: Immediately after concussion, injured subjects performed significantly below preinjury baseline and below uninjured controls on the SAC. Measurable deficits in orientation, concentration, and memory were evident immediately after concussion. A decline in SAC score at time of injury was 95% sensitive and 76% specific in accurately classifying injured and uninjured subjects on the sideline. Injured subjects demonstrated significant improvements in SAC score 48 hours after injury. CONCLUSIONS: Standardized mental status testing can be a valuable tool to assist the sports medicine clinician in detecting the immediate effects of concussion on mental status, tracking resolution of immediate postconcussive mental status abnormalities, and making more informed decisions on return to play after injury.

Duration of Maintained Hamstring Flexibility After a One-Time, Modified Hold-Relax Stretching Protocol.

Abstract: OBJECTIVE: Previous research suggests proprioceptive neuromuscular facilitation (PNF) stretching techniques produce greater increases in range of motion than passive, ballistic, or static stretching methods. The purpose of our study was to measure the duration of maintained hamstring flexibility after a 1-time, modified hold-relax stretching protocol. DESIGN AND SETTING: The study had a 1 x 1 mixed-model, repeated-measures design. The independent variables were group (control and experimental) and time (0, 2, 4, 6, 8, 16, and 32 minutes). The dependent variable was hamstring flexibility as measured in degrees of active knee extension with the hip flexed to 90 degrees. Measurements were taken in a preparatory military academy athletic training room. SUBJECTS: Thirty male subjects (age, 18.8 +/- 0.63 years; height, 185.2 +/- 14.2 cm; weight, 106.8 +/- 15.7 kg) with limited hamstring flexibility in the right lower extremity were randomly assigned to a control (no-stretch) group or an experimental (stretch) group. MEASUREMENTS: All subjects performed 6 warm-up active knee extensions, with the last repetition serving as the prestretch measurement. The experimental group received 5 modified (no-rotation) hold-relax stretches, whereas the control group rested quietly supine on a table for 5 minutes. Posttest measurements were recorded for both groups at 0, 2, 4, 6, 8, 16, and 32 minutes. RESULTS: The repeated-measures analysis of variance revealed a significant group-by-time interaction, a significant main effect for group, and a significant main effect for time. Dunnett post hoc analysis revealed a significant improvement in knee-extension range of motion in the experimental group that lasted 6 minutes after the stretching protocol ended. CONCLUSIONS: Our findings suggest that a sequence of 5 modified hold-relax stretches produced significantly increased hamstring flexibility that lasted 6 minutes after the stretching protocol ended.

Isokinetic Hamstrings:Quadriceps Ratios in Intercollegiate Athletes.

Abstract: OBJECTIVE: To compare the differences in the concentric hamstrings:quadriceps (H:Q) ratio among athletes in different sports at 3 velocities. DESIGN AND SETTING: We measured the H:Q ratio of both knees using the Biodex Pro Isokinetic Device. SUBJECTS: Eighty-one male and female collegiate athletes. MEASUREMENTS: We performed analyses for sport, velocity, and side of body for each sex. To compare the means of the concentric H:Q ratios for mean peak torque and mean total work, a 2 x 3 x 4 mixed-factorial analysis of variance was computed for women and a 2 x 2 x 3 mixed-factorial analysis of variance was computed for men. RESULTS: We observed no significant interactions for men and women for the concentric H:Q ratio for mean peak torque. There was a significant mean difference among velocity conditions and a significant difference for men with respect to velocity. No significant differences were found for side of body or sport. CONCLUSIONS: The H:Q ratio increased as velocity increased. No differences existed for the H:Q ratio for sport or side of body.

The meniscus: review of basic principles with application to surgery and rehabilitation.

Abstract: Objective To review basic meniscal anatomy, histology, and biomechanical principles as they apply to surgery and rehabilitation. Data sources We searched MEDLINE and CINAHL for the years 1960-1999 using the terms meniscus,surgery,rehabilitation,meniscal repair, and arthroscopy. Data synthesis Injuries to a healthy meniscus are usually produced by a compressive force coupled with transverse-plane tibiofemoral rotation as the knee moves from flexion to extension during rapid cutting or pivoting. The goal of meniscal surgery is to restore a functional meniscus to prevent the development of degenerative osteoarthritis in the involved knee. The goal of rehabilitation is to restore patient function based on individual needs, considering the type of surgical procedure, which meniscus was repaired, the presence of coexisting knee pathology (particularly ligamentous laxity or articular cartilage degeneration), the type of meniscal tear, the patient's age, preoperative knee status (including time between injury and surgery), decreased range of motion or strength, and the patient's athletic expectations and motivations. Progressive weight bearing and joint stress are necessary to enhance the functionality of the meniscal repair; however, excessive shear forces may be disruptive. Prolonged knee immobilization after surgery can result in the rapid development of muscular atrophy and greater delays in functional recovery. Conclusions/recommendations Accelerated joint mobility and weight-bearing components of rehabilitation protocols represent the confidence placed in innovative surgical fixation methods. After wound healing, an aquatic therapy environment may be ideal during all phases of rehabilitation after meniscal surgery (regardless of the exact procedure), providing the advantages of controlled weight bearing and mobility progressions. Well-designed, controlled, longitudinal outcome studies for patients who have undergone meniscectomy, meniscal repair, or meniscal reconstruction are lacking.

Acceleration-Deceleration Sport-Related Concussion: The Gravity of It All.

Abstract: OBJECTIVE: To discuss a newtonian physics model for understanding and calculating acceleration-deceleration forces found in sport-related cerebral concussions and to describe potential applications of this formula, including (1) an attempt to measure the forces applied to the brain during acceleration-deceleration injuries, (2) a method of accruing objective data regarding these forces, and (3) use of these data to predict functional outcome, such as neurocognitive status, recovery curves, and return to play. BACKGROUND: Mild concussion in sports has gained considerable attention in the last decade. Athletic trainers and team physicians have attempted to limit negative outcomes by gaining a better understanding of the mechanisms and severity of mild head injuries and by developing meaningful return-to-play criteria. Mild head injury in sports has become an even greater area of focus and concern, given the negative neurobehavioral outcomes experienced by several recent high-profile professional athletes who sustained repeated concussions. Applying the principles of physics to characterize injury types, injury severity, and outcomes may further our development of better concussion management techniques and prevention strategies. DESCRIPTION: We describe the search for models to explain neuronal injury secondary to concussion and provide an exploratory method for quantifying acceleration-deceleration forces and their relationship to severity of mild head injury. Implications for injury prevention and reduction of morbidity are also considered.

Monitoring Resolution of Postconcussion Symptoms in Athletes: Preliminary Results of a Web-Based Neuropsychological Test Protocol.

Abstract: OBJECTIVE: A new Web-based neuropsychological test was field tested to determine usefulness in detecting and monitoring resolution of symptoms after sport-related concussions and in providing objective information for return-to-play decisions. DESIGN AND SETTING: We obtained neuropsychological baseline data on all subjects. After concussion, subjects were administered alternate, equivalent follow-up tests until symptoms resolved. Follow-up testing typically occurred at 1- to 2-day intervals after the concussion. SUBJECTS: Baseline testing was obtained for 834 athletes as part of ongoing field trials. Subsequently, 26 athletes sustained concussions and were studied. MEASUREMENTS: We administered The Concussion Resolution Index (CRI) at baseline and alternate forms posttrauma. Follow-up tests included a self-report inventory of neurophysiologic symptoms. RESULTS: A total of 88% of patients were identified as symptomatic on initial postconcussion testing. The CRI appeared relatively resistant to retest effects, and multiple administrations tracked resolution of symptoms over short and extended time periods. CONCLUSIONS: Although the CRI is still in field trials, preliminary data indicate that the CRI may be a useful method for athletic trainers and other professionals to expeditiously track resolution of symptoms after sport-related concussion.

The anatomy and mechanisms of syndesmotic ankle sprains.

Abstract: OBJECTIVE To present a comprehensive review of the anatomy, biomechanics, and mechanisms of tibiofibular syndesmosis ankle sprains. DATA SOURCES MEDLINE (1966-1998) and CINAHL (1982-1998) searches using the key words syndesmosis, tibiofibular, ankle injuries, and ankle injuries-etiology. DATA SYNTHESIS Stability of the distal tibiofibular syndesmosis is necessary for proper functioning of the ankle and lower extremity. Much of the ankle's stability is provided by the mortise formed around the talus by the tibia and fibula. The anterior and posterior inferior tibiofibular ligaments, the interosseous ligament, and the interosseous membrane act to statically stabilize the joint. During dorsiflexion, the wider portion anteriorly more completely fills the mortise, and contact between the articular surfaces is maximal. The distal structures of the lower leg primarily prevent lateral displacement of the fibula and talus and maintain a stable mortise. A variety of mechanisms individually or combined can cause syndesmosis injury. The most common mechanisms, individually and particularly in combination, are external rotation and hyperdorsiflexion. Both cause a widening of the mortise, resulting in disruption of the syndesmosis and talar instability. CONCLUSIONS AND RECOMMENDATION: Syndesmosis ankle injuries are less common than lateral ankle injuries, are difficult to evaluate, have a long recovery period, and may disrupt normal joint functioning. To effectively evaluate and treat this injury, clinicians should have a full understanding of the involved structures, functional anatomy, and etiologic factors.

The Effects of Sex, Joint Angle, and the Gastrocnemius Muscle on Passive Ankle Joint Complex Stiffness

Abstract: OBJECTIVE: To assess the effects of sex, joint angle, and the gastrocnemius muscle on passive ankle joint complex stiffness (JCS). DESIGN AND SETTING: A repeated-measures design was employed using sex as a between-subjects factor and joint angle and inclusion of the gastrocnemius muscle as within-subject factors. All testing was conducted in a neuromuscular research laboratory. SUBJECTS: Twelve female and 12 male healthy, physically active subjects between the ages of 18 and 30 years volunteered for participation in this study. The dominant leg was used for testing. No subjects had a history of lower extremity musculoskeletal injury or circulatory or neurologic disorders. MEASUREMENTS: We determined passive ankle JCS by measuring resistance to passive dorsiflexion (5 degrees.s(-1)) from 23 degrees plantar flexion (PF) to 13 degrees dorsiflexion (DF). Angular position and torque data were collected from a dynamometer under 2 conditions designed to include or reduce the contribution of the gastrocnemius muscle. Separate fourth-order polynomial equations relating angular position and torque were constructed for each trial. Stiffness values (Nm.degree(-1)) were calculated at 10 degrees PF, neutral (NE), and 10 degrees DF using the slope of the line at each respective position. RESULTS: Significant condition-by-position and sex-by-position interactions and significant main effects for sex, position, and condition were revealed by a 3-way (sex-by-position, condition-by-position) analysis of variance. Post hoc analyses of the condition-by-position interaction revealed significantly higher stiffness values under the knee-straight condition compared with the knee-bent condition at both ankle NE and 10 degrees DF. Within each condition, stiffness values at each position were significantly higher as the ankle moved into DF. Post hoc analysis of the sex-by-position interaction revealed significantly higher stiffness values at 10 degrees DF in the male subjects. Post hoc analysis of the position main effect revealed that as the ankle moved into dorsiflexion, the stiffness at each position became significantly higher than at the previous position. CONCLUSIONS: The gastrocnemius contributes significantly to passive ankle JCS, thereby providing a scientific basis for clinicians incorporating stretching regimens into rehabilitation programs. Further research is warranted considering the cause and application of the sex-by-position interaction.

Multiple Concussions and Neuropsychological Functioning in Collegiate Football Players.

Abstract: OBJECTIVE: To document neurocognitive and neurobehavioral consequences of 1 versus 2 concussions. DESIGN AND SETTING: Nonequivalent, pretest-posttest cohort design with multiple dependent measures. Participants were selected from a large sample of athletes who participated in a comprehensive, multiuniversity study of football-related concussion. SUBJECTS: College football players who sustained 1 and 2 grade 1 concussive injuries were matched for age, education, and duration of competitive football. MEASUREMENTS: Neuropsychological tests and symptoms checklists. RESULTS: Multivariate analysis of variance did not show a statistically significant difference in test performance between players with 1 or 2 concussions. Chi square analyses revealed that concussions significantly increased the number of symptom complaints, but symptoms returned to baseline by 10 days postinjury. The effects of 2 injuries did not appear to be significantly greater than that of a single injury. Differences in response to concussion were observed. CONCLUSIONS: Neurocognitive and neurobehavioral consequences of 2 concussions did not appear to be significantly different from those of 1 concussion, but methodologic issues place limitations on data interpretation. Additional studies are needed to clarify the neuropsychological consequences of multiple concussions.

Serial Testing of Postural Control after Acute Lateral Ankle Sprain

Abstract: OBJECTIVE: To identify subjects' changes in postural control during single-leg stance in the 4 weeks after acute lateral ankle sprain. DESIGN AND SETTING: We used a 2 x 2 x 3 (side-by-plane-by-session) within-subjects design with repeated measures on all 3 factors. All tests were performed in a university laboratory. SUBJECTS: Seventeen young adults (9 men, 8 women; age, 21.8 +/- 5.9 years; mass, 74.9 +/- 10.5 kg; height, 176.9 +/- 7.1 cm) who had sustained unilateral acute mild or moderate lateral ankle sprains. MEASUREMENTS: Measures of center-of-pressure excursion length, root mean square velocity of center-of-pressure excursions (VEL), and range of center-of-pressure excursions (RANGE) were calculated separately in the frontal and sagittal planes during 5-second trials of static single-leg stance. RESULTS: We noted significant side-by-plane-by-session interactions for magnitude of center-of-pressure excursions in a given trial (PSL) (P =.004), VEL (P =.011), and RANGE (P =.009). Both PSL and VEL in the frontal plane were greater in the injured limbs compared with the uninjured limbs on day 1 and during week 2 but not during week 4, whereas sagittal-plane differences existed during all 3 testing sessions. Injured-limb, frontal-plane RANGE scores were greater than uninjured values at day 1 but not during weeks 2 or 4. No significant differences in sagittal-plane RANGE scores were seen. CONCLUSIONS: Postural control was significantly impaired in the injured limbs at day 1 and during week 2 after lateral ankle sprain but not during week 4. Consistent improvement in postural control measures on both injured and uninjured limbs was seen throughout the 4 weeks after ankle sprain.

Clinical Instructors' and Student Athletic Trainers' Perceptions of Helpful Clinical Instructor Characteristics.

Abstract: OBJECTIVE: To compare the perceptions of students and clinical instructors regarding helpful clinical instructor characteristics. DESIGN AND SETTING: We developed a questionnaire containing helpful clinical instructor characteristics for facilitating student learning from a review of the medical and allied health clinical education literature. Respondents rated clinical instructor characteristics from 1 (among the least helpful) to 10 (among the most helpful). Respondents also identified the overall 10 most helpful and 10 least helpful characteristics. SUBJECTS: A total of 206 undergraduate students and 46 clinical instructors in the National Athletic Trainers' Association District 4 athletic training education programs accredited by the Commission on Accreditation of Allied Health Education Programs responded to the survey. MEASUREMENTS: We computed individual-item and subgroup mean scores for students, clinical instructors, and combined students and instructors. Pearson product moment correlations were computed to evaluate the level of agreement between students and instructors. Correlations were also computed to evaluate the level of agreement between the open-ended responses and the Likert-scale responses. RESULTS: Agreement was high between the students' and the clinical instructors' ratings of individual items. Agreement was also high between individual-item means and the directed, open-ended 10 most helpful and 10 least helpful clinical instructor characteristics. Modeling professional behavior was considered the most helpful subgroup of clinical instructor characteristics. Integration of knowledge and research into clinical education was considered the least helpful subgroup of clinical instructor characteristics. CONCLUSIONS: Clinical instructors should model professional behavior to best facilitate student learning. Integration of research into clinical education may need more emphasis.

Neuromuscular Evaluation of Trunk-Training Exercises.

Abstract: OBJECTIVE: To evaluate the neuromuscular activation profiles of trunk muscles in commonly used gymnastic strength exercises with a polymyographic set-up and to describe the training effects of each exercise. DESIGN AND SETTING: Subjects performed 9 repetitions of each of 12 gymnastic exercises. Variations of 5 trunk flexions, 5 extensions, and 2 lateral-flexion movements were performed under standardized test conditions. SUBJECTS: Ten healthy subjects (men and women) who were familiar with the exercises participated in the study. MEASUREMENTS: We recorded surface electromyograms (EMGs) from the rectus abdominis, external oblique, rectus femoris, middle trapezius, erector spinae at T12 and L3, gluteus maximus, and semitendinosus and semimembranosus muscles. Recording of each repetition cycle was triggered by a flexible electronic goniometer attached to the trunk. The raw EMG signals were rectified, smoothed, amplitude normalized to maximal voluntary contraction (MVC), and averaged for the last 8 repetitions. RESULTS: Pure spine-flexion exercises, such as a curl-up, produced sufficient and isolated activation (greater than 50% MVC) of the abdominal muscles. When flexion of the spine was combined with hip flexion (sit-up), the peak activation was increased. Lateral-flexion tasks targeted primarily the external oblique muscle, which demonstrated high activity in side-lying flexion tasks. Back- and hip-extension exercises, such as bridging and diagonal hip and shoulder extension, produced only moderate mean activities (less than 35% MVC) in the trunk-extensor muscles. Trunk-extension exercises with combined hip extension increased the EMG activity to 50% MVC but only at the end of the extension. CONCLUSIONS: Individual responses to each exercise varied markedly, which complicated the classification of exercise effects. However, within the limitations of the study, we found that the chosen abdominal exercises provided an effective training stimulus for the trunk-flexor muscles, whereas in the back- and hip-extension exercises, the neuromuscular activation tended to be too low or unspecific to qualify as muscle-specific training.

Muscle Temperature Is Affected by Overlying Adipose When Cryotherapy Is Administered.

Abstract: OBJECTIVE: To investigate the relationship between the amount of overlying adipose and intramuscular temperature change during and after a 20-minute crushed-ice pack treatment. DESIGN AND SETTING: Subjects were divided into 3 equal groups according to calf skinfold thickness: 8 mm or less, 10 to 18 mm, and 20 mm or greater. Intramuscular temperature was monitored at 1 cm and 3 cm below the subcutaneous fat in the left medial calf during and after a 1.8-kg crushed-ice pack treatment. SUBJECTS: Thirty uninjured college students volunteered to be subjects. MEASUREMENTS: Intramuscular temperature was recorded every 10 seconds over a 20-minute treatment and for 30 minutes posttreatment. RESULTS: Intramuscular temperature decreases between adipose groups at the end of treatment at both 1 cm and 3 cm below the subcutaneous fat were significantly different. At 1 cm within the muscle, the temperature decreases were 14.43 degrees C, 9.06 degrees C, and 5.00 degrees C for 8-mm or less, 10- to 18-mm, and 20-mm or greater skinfolds, respectively. At 3 cm, temperatures were 6.22 degrees C, 3.86 degrees C, and 2.42 degrees C, respectively. By 30 minutes posttreatment at 1 cm, the 8-mm or less and 10- to 18-mm groups rewarmed 5.39 degrees C and 2.22 degrees C, respectively, but the 20-mm or greater group was 0.49 degrees C colder than at the conclusion of the treatment. At 3 cm, temperatures in all 3 groups were colder at 30 minutes posttreatment than they were at the end of the treatment, 1.63 degrees C, 1.83 degrees C, and 2.10 degrees C for 8-mm or less, 10- to 18-mm, and 20-mm or greater skinfolds, respectively. CONCLUSIONS: The amount of adipose over the therapy site is a significant factor in the extent of intramuscular temperature change that occurs during and after cryotherapy. Adipose should, therefore, be taken into account in determining appropriate treatment protocols.

Osteitis Pubis Syndrome in the Professional Soccer Athlete: A Case Report.

Abstract: OBJECTIVE: To describe the pathomechanics, diagnostic procedures, classification, and conservative management of the osteitis pubis syndrome in the elite soccer athlete. BACKGROUND: Groin injuries can be the most difficult sport injuries to accurately diagnose and treat. Osteitis pubis is a painful, chronic syndrome that affects the symphysis pubis, adductor and abdominal muscles, and surrounding fascia. If misdiagnosed or mismanaged, osteitis pubis can run a prolonged and disabling course. The abdominal and adductor muscles have attachments to the symphysis pubis but act antagonistically to each other, predisposing the symphysis pubis to mechanical traction microtrauma and resulting in osteitis pubis. These antagonistic forces are most prevalent in kicking sports, such as soccer or football. DESCRIPTION: We provide a retrospective review of the demographics, diagnostic criteria and procedures, and conservative management of osteitis pubis in a professional soccer team. Osteitis pubis represented 3% to 5% of all injuries sustained by our professional soccer team between 1989 and 1997; 71.4% of those presenting with osteitis pubis were classified as having stage I disease, with a mean recovery time of 26.7 days. Midfielders were most affected by the syndrome (42.8%), whereas defenders and forwards exhibited equal incidences (25.7%) of osteitis pubis. Conservative management included nonsteroidal anti-inflammatory medication, electric stimulation, ultrasound, laser, cryomassage, and a progressive rehabilitation program. CLINICAL ADVANTAGES: Athletes who participated in this conservative management program appeared to return to full sport participation earlier and with fewer restrictions than the current literature seems to suggest. A 4-stage diagnostic criteria system was helpful in determining the course of treatment.

A Survey of Practice Patterns in Concussion Assessment and Management.

Abstract: OBJECTIVES: To identify methods used by athletic trainers to assess concussions and the use of that information to assist in return-to-play decisions and to determine athletic trainers' familiarity with new standardized methods of concussion assessment. DESIGN AND SETTING: A 21-item questionnaire was distributed to attendees of a minicourse at the 1999 National Athletic Trainers' Association Annual Meeting and Clinical Symposia entitled "Use of Standardized Assessment of Concussion (SAC) in the Immediate Sideline Evaluation of Injured Athletes." SUBJECTS: A total of 339 valid surveys were returned by the attendees of the minicourse. MEASUREMENTS: We used frequency analysis and descriptive statistics. RESULTS: Clinical examination (33%) and a symptom checklist (15.3%) were the most common evaluative tools used to assess concussions. The Colorado Guidelines (28%) were used more than other concussion management guidelines. Athletic trainers (34%) and team physicians (40%) were primarily responsible for making decisions regarding return to play. A large number of respondents (83.5%) believed that the use of a standardized method of concussion assessment provided more information than routine clinical and physical examination alone. CONCLUSIONS: Athletic trainers are using a variety of clinical tools to evaluate concussions in athletes. Clinical evaluation and collaboration with physicians still appear to be the primary methods used for return-to-play decisions. However, athletic trainers are beginning to use standardized methods of concussion to evaluate these injuries and to assist them in assessing the severity of injury and deciding when it is safe to return to play.

Concussion in Rugby: The Hidden Epidemic.

Abstract: OBJECTIVE: To determine the incidence of concussion in high school rugby players and compare the findings with the relevant published literature. DESIGN AND SETTING: Prospective data collection in one US high school rugby program. SUBJECTS: Two teams followed for 3 years. MEASUREMENTS: Injury rate, injury severity, and time withheld from competition. RESULTS: Seventeen concussions were recorded, accounting for 25% of all reported injuries. The incidence rate for concussion was 3.8 per 1000 athlete-exposures (95% confidence interval, 2.0-5.7) or 11.3 per 100 player-seasons (95% confidence interval, 5.9-16.7). Of the 17 concussions, 14 were Cantu grade 1, 2 were grade 2, and 1 was grade 3. Concussions accounted for 25% of all days lost from rugby participation due to injury. CONCLUSIONS: The incidence of concussion in this study was higher than previously reported in other studies. METHODologic limitations and administrative rules that required suspension for injured players may have suppressed reporting in previous epidemiologic studies. The incidence of concussion in rugby is probably much higher than previously suggested. Language: en

Cerebral Concussion: Causes, Effects, and Risks in Sports.

Abstract: OBJECTIVE: To characterize the causes, effects, and risks associated with concussion in sports. BACKGROUND: Concussion is an injury associated with sports and is most often identified with boxing, football, ice hockey, and the martial arts. In addition, recent research has shown that concussion occurs in many different sports. In the decade of the 1990s, concussion became a primary issue for discussion among the media, sports sponsors, sports medicine professionals, and athletes. DESCRIPTION: Concussion is an injury that results from a wide variety of mechanisms and has numerous signs and symptoms that are common to different types of injury. Continued improvement in prevention and management strategies for concussion requires a strong body of research from a variety of different disciplines. It is essential that research efforts focus on both prevention and management and that researchers and clinicians work closely toward their common goals. CONCLUSIONS/RECOMMENDATIONS: Until the research community is able to provide sound recommendations for the prevention and management of the concussion, the care of the injured player falls squarely on the clinician. It is important for sports medicine professionals to continue to stay up to date on the advances in understanding concussions and how to care individually for each player who sustains a concussion. Language: en

Loss of Consciousness: Pathophysiology and Implications in Grading and Safe Return to Play.

Abstract: OBJECTIVE: To provide historical background and current concepts regarding the importance of loss of consciousness (LOC) in the evaluation of concussion and athletes. DATA SOURCES: A MEDLINE search identified scientific and clinical articles on sport concussion management published from 1966 to present. Discussions were held with authors of selected reports. Recent research findings reported at national meetings were reviewed. DATA SYNTHESIS: The relative importance of LOC in the evaluation of concussion was reviewed in light of scientific and clinical evidence in the literature. Comments made by authors of concussion grading scales were considered in the development of expert consensus statements. CONCLUSIONS/RECOMMENDATIONS: The observation of LOC at the time of concussion must be viewed as reflecting a potentially worrisome traumatic brain injury. LOC is followed by more severe acute mental status abnormalities and carries a greater risk of intracranial pathology than concussion without LOC. Prolonged LOC represents a neurologic emergency, which may require neurosurgical intervention. Lingering symptoms of concussion, even without LOC, should be monitored closely and managed according to established guidelines for safe return to play.

Classification of Sport-Related Head Trauma: A Spectrum of Mild to Severe Injury.

Abstract: OBJECTIVE: To identify the types of injuries the human brain incurs as a result of traumatic forces applied to the cranium. In athletic events and endeavors, the full spectrum of intracranial hemorrhages in various compartments, raised intracranial pressure, and diffuse nonhemorrhagic damage may be seen. In this review, we describe these serious injuries and the more common mild traumatic brain injury in their clinical presentations and relate concussion classification to the overall picture of traumatic brain injury. METHODS: Our cumulative experience with athletic injuries, both at the catastrophic and mild traumatic brain injury levels, has led us to a management paradigm that serves to guide us in the classification and treatment of these athletes. DISCUSSION: The occurrence of intracranial injuries in sports has now been well documented. Intracranial hematomas (epidural, subdural, and parenchymal) and cerebral contusions can result from head injury. Many patients sustain a diffuse brain injury, resulting in elevated intracranial pressures, without a blood clot or mass lesion. The classification of concussion and the use of concussion guidelines are not uniform. However, the major emphases are agreed upon: the close and careful scrutiny of the athlete, an expeditious but reliable neurologic examination, and proper on-field management. Return-to-play decisions are based on many factors that affect normal functioning, both on and off the playing field. CONCLUSIONS: Sufficient knowledge now exists to allow us to carefully evaluate the injured athlete, to place him or her in the management scheme to minimize the potential for permanent cerebral dysfunction, and to know when the athlete can safely return to contact sport participation.

Neuromuscular Response Characteristics in Men and Women After Knee Perturbation in a Single-Leg, Weight-Bearing Stance.

Abstract: Objective: We examined whether muscle response times and activation patterns in the lower extremity differed between men and women in response to a rotational knee perturbation while standing in a single-leg, weight-bearing stance. Design and Setting: We used a lower extremity perturbation device to produce a sudden, forward, and either internal or external rotation moment of the trunk and femur relative to the weight-bearing tibia. Subjects completed 10 trials of both internal and external rotation perturbation; the first 5 acceptable trials were averaged and used for data analysis. Two separate, repeated-measures analyses of variance were used to compare myoelectric response times and activation patterns between men and women for both internal and external rotation perturbation. Subjects: Thirty-two female (19 lacrosse, 13 soccer) and 32 male (lacrosse) healthy intercollegiate athletes participated in the study. Measurements: We used surface electromyography to record long latency reflex times of the medial and lateral quadriceps, hamstring, and gastrocnemius muscles. Results: Women responded faster than men, primarily due to a shorter latency in quadriceps activation. However, men and women exhibited no difference in muscle-recruitment order. Conclusions: Although men and women demonstrated similar muscle-recruitment patterns to an imposed lower extremity perturbation, women tended to activate their quadriceps earlier than men. Whether this earlier quadriceps activation diminishes the ability of the hamstrings to adequately stabilize the knee joint or subjects the anterior cruciate ligament to greater risk of injury is still unknown and requires further study. Furthermore, although surface electromyography and measurement of myoelectric response times are useful in evaluating the timing, activation order, and coactivity patterns of the knee musculature, future studies should evaluate sex differences across the complete response continuum, including measures of intrinsic muscle stiffness, electromechanical delay, and time to force production.

Heading in Soccer: Integral Skill or Grounds for Cognitive Dysfunction?

Abstract: OBJECTIVE: To critically review the literature concerning the effect of purposeful heading of a soccer ball and head injuries on reported cognitive dysfunction in soccer players. DATA SOURCES: We searched MEDLINE (1965-2001) and SPORTDiscus (1975-2001) for refereed articles in English combining key words for soccer (eg, soccer, football, association football ) with key words for head injuries (eg, concussion, head injury). In addition, literature on cognition and head injuries was obtained. We reviewed reference lists of current literature for pertinent citations that might not have been found in the search procedures. DATA SYNTHESIS: The fact that soccer players (and other athletes) have selected cognitive deficits is not questioned, and the popular press is quick to publicize results of questionable validity. The reasons for such deficits are many. Much of the early data implied that heading was the culprit; however, subsequent research has suggested that other interpretations and factors may be potential explanations for these deficits. The current focus is on concussions, a known factor in cognitive dysfunction and a common head injury in soccer. CONCLUSIONS/RECOMMENDATIONS: It is difficult to blame purposeful heading for the reported cognitive deficits when actual heading exposure and details of the nature of head-ball impact are unknown. Concussions are a common head injury in soccer (mostly from head-head or head-ground impact) and a factor in cognitive deficits and are probably the mechanism of the reported dysfunction.

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

Abstract: 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.

Catastrophic Head Injuries in High School and Collegiate Sports.

Abstract: OBJECTIVE: To describe the incidence of catastrophic head injuries in a variety of high school and college sports DESIGN AND SETTING: Data on catastrophic head injuries were compiled in a national surveillance system maintained by the National Center for Catastrophic Sports Injury Research The data were compiled with the assistance of coaches, athletic trainers, athletic directors, executive officers of state and national athletic organizations, a national newspaper clipping service, professional associates of the researchers, and national sport organizations SUBJECTS: Data included all high school and college athletic programs in the United States MEASUREMENTS: Background information on the athlete (age, height, weight, experience, previous injury, etc), accident information, immediate and postaccident medical care, type of injury, and equipment involved Autopsy reports were used when available RESULTS: A football-related fatality has occurred every year from 1945 through 1999, except for 1990 Head-related deaths accounted for 69% of football fatalities, cervical spinal injuries for 163%, and other injuries for 147% High school football produced the greatest number of football head-related deaths From 1984 through 1999, 69 football head-related injuries resulted in permanent disability Sixty-three of the injuries were associated with high school football and 6 with college football Although football has received the most attention, other sports have also been associated with head-related deaths and permanent disability injuries From 1982 through 1999, 20 deaths and 19 permanent disability injuries occurred in a variety of sports Track and field, baseball, and cheerleading had the highest incidence of these catastrophic injuries Three deaths and 3 injuries resulting in permanent disability have occurred in female participants CONCLUSIONS/RECOMMENDATIONS: Reliable data collection systems and continual analysis of the data can help us to reduce the number of catastrophic head-related injuries I include additional recommendations for injury prevention

Effects of Hot or Cold Water Immersion and Modified Proprioceptive Neuromuscular Facilitation Flexibility Exercise on Hamstring Length.

Abstract: OBJECTIVE: To compare the changes in hamstring length resulting from modified proprioceptive neuromuscular facilitation flexibility training in combination with cold-water immersion, hot-water immersion, and stretching alone. DESIGN AND SETTING: Training-only subjects stood motionless for 10 minutes, while subjects in the cold group stood in a cold-water bath (8 degrees +/- 1 degrees C) immersed up to the gluteal fold for 10 minutes, and subjects in the hot group stood in a hot-water bath (44 degrees +/- 1 degrees C) immersed up to the gluteal fold for 10 minutes. All subjects exercised only the right lower limb using a modified proprioceptive neuromuscular facilitation flexibility protocol, consisting of 1 set of 4 repetitions. This procedure was followed for 5 consecutive days. SUBJECTS: Forty-five uninjured subjects (21 women, 24 men; age range, 18-25 years) were randomly assigned to the cold, hot, or stretching-alone group. MEASUREMENTS: Subjects were measured for maximum active hip flexion on the first and fifth days. RESULTS: Group results were assessed using a 2 x 3 analysis of variance, comparing changes in hamstring length from pretest to posttest. All 3 groups had significant improvements in hamstring length (pretest to posttest) (P <.05). However, no significant differences occurred among groups. CONCLUSIONS: No advantage was apparent in using complete hot or cold immersion to increase hamstring length in healthy subjects.

Management of Cerebral Concussion in Sports: The Athletic Trainer's Perspective.

Abstract: Objective: To present a new approach in the evaluation and management of concussion from the athletic trainer’s perspective. Background: The evaluation and management of concussion continues to be a controversial topic among sports medicine professionals. Inconsistent management, lack of objective data, and confusion concerning assessment techniques may lead to inappropriate decisions regarding when to return an athlete to competition after concussion. In this article, we provide recommendations and considerations for the certified athletic trainer in the management of concussion. We also present a quantifiable assessment technique that provides more information on which return-to-play decisions can be made; this technique can be used during the initial sideline examination as well as during subsequent follow-up examinations. Recommendations: Certified athletic trainers and team physicians should consistently use appropriate grading scales. Assessment of concussion should include a symptom checklist, the Balance Error Scoring System, and the Standardized Assessment of Concussion, and the results should be compared with the athlete’s normal baseline scores. Follow-up neuropsychological and postural stability testing is recommended. Return-to-play decisions should be based on the grade of concussion, scores on objective tests, and presence of concussive symptoms during exertional activities.

Qualitative Inquiry in Athletic Training: Principles, Possibilities, and Promises.

Abstract: OBJECTIVE: To discuss the principles of qualitative research and provide insights into how such methods can benefit the profession of athletic training. BACKGROUND: The growth of a profession is influenced by the type of research performed by its members. Although qualitative research methods can serve to answer many clinical and professional questions that help athletic trainers navigate their socioprofessional contexts, an informal review of the Journal of Athletic Training reveals a paucity of such methods. DESCRIPTION: We provide an overview of the characteristics of qualitative research and common data collection and analysis techniques. Practical examples related to athletic training are also offered. APPLICATIONS: Athletic trainers interact with other professionals, patients, athletes, and administrators and function in a larger society. Consequently, they are likely to face critical influences and phenomena that affect the meaning they give to their experiences. Qualitative research facilitates a depth of understanding related to our contexts that traditional research may not provide. Furthermore, qualitative research complements traditional ways of thinking about research itself and promotes a greater understanding related to specific phenomena. As the profession of athletic training continues to grow, qualitative research methods will assume a more prominent role. Thus, it will be necessary for consumers of athletic training research to understand the functional aspects of the qualitative paradigm.

A Review of Sudden Cardiac Death in Young Athletes and Strategies for Preparticipation Cardiovascular Screening.

Abstract: Objectives: To provide the reader with an overview of the many causes of sudden cardiac death in young athletes and to present various strategies for preparticipation cardiovascular screening. Data Source: A MEDLINE search using the phrase sudden cardiac death and the key word athlete for the years 1980 to 2000. Data Synthesis: Sudden cardiac death is a rare event in athletics. More than 20 different causes have been described, but most cases result from a few distinct entities. Most afflicted athletes have no symptoms before death. Many attempts have been made to detect those at risk for sudden cardiac death before athletic participation. At this time, a thorough history and physical examination are the most efficient screening methods for detecting cardiovascular abnormalities. Studies show that the current status of preparticipation cardiovascular screening of high school and college athletes nationwide is poor. Conclusions and Recommendations: The use of diagnostic tests to screen for cardiovascular abnormalities is ineffective and inefficient. The most prudent and effective methods of preparticipation screening for cardiovascular abnormalities at this time are a history and physical examination in accordance with the American Heart Association guidelines. Athletic trainers must ensure that their institutions comply with these minimum standards.