Sports concussion assessment: the effect of exercise on dynamic and static balance.

This study determined the effect of exercise on measures of static and dynamic balance used in the assessment of sports-related concussion (SRC). A balanced three-group cross-over randomized design was used with three levels of exercise verified by blood-lactate, heart rate and "perceived-exertion": no exercise/rest (NE), moderate-intensity exercise (ME), and high-intensity exercise (HE). Participants performed two timed balance tasks: tandem gait (TG) and single-leg stance (SLS); pre- and post-exercise and 15 min after exercise. Linear mixed-models with adjusted means and contrasts compared exercise effects. Ninety asymptomatic participants (45♂:45♀) were recruited. When times were contrasted with NE; HE resulted in a significant decrease in SLS (P<0.001) and TG (P<0.001) performance immediately following exercise. Fifteen minutes of recovery improved SLS (P<0.001) and TG (P=0.011) from post-exercise performance. ME caused a significant decrease in performance in SLS (P=0.038) but not TG (P=0.428). No statistically significant change occurred following ME in any tasks after 15-min recovery (SLS P=0.064; TG P=0.495). Test-retest reliability was considerably higher for the dynamic task compared with the static task. The reliability of static and dynamic balance tasks, and the change in performance following exercise, have implications for the immediate assessment of SRC, as these measures are utilized in concussion assessment instruments.

Iliotibial band syndrome: an examination of the evidence behind a number of treatment options.

Iliotibial band (ITB) syndrome (ITBS) is a common cause of distal lateral thigh pain in athletes. Treatment often focuses on stretching the ITB and treating local inflammation at the lateral femoral condyle (LFC). We examine the area's anatomical and biomechanical properties. Anatomical studies of the ITB of 20 embalmed cadavers. The strain generated in the ITB by three typical stretching maneuvers (Ober test; Hip flexion, adduction and external rotation, with added knee flexion and straight leg raise to 30 degrees ) was measured in five unembalmed cadavers using strain gauges. Displacement of the Tensae Fasciae Latae (TFL)/ITB junction was measured on 20 subjects during isometric hip abduction. The ITB was uniformly a lateral thickening of the circumferential fascia lata, firmly attached along the linea aspera (femur) from greater trochanter up to and including the LFC. The microstrain values [median (IQR)] for the OBER [15.4(5.1-23.3)me], HIP [21.1(15.6-44.6)me] and SLR [9.4(5.1-10.7)me] showed marked disparity in the optimal inter-limb stretching protocol. HIP stretch invoked significantly (Z=2.10, P=0.036) greater strain than the SLR. TFL/ITB junction displacement was 2.0+/-1.6 mm and mean ITB lengthening was <0.5% (effect size=0.04). Our results challenge the reasoning behind a number of accepted means of treating ITBS. Future research must focus on stretching and lengthening the muscular component of the ITB/TFL complex.

Patient-based not problem-based learning: an Oslerian approach to clinical skills, looking back to move forward.

CONTEXT: There have been significant changes in the past decade in both the curriculum and its delivery, in undergraduate medical education. Many of these changes have been made simultaneously, preventing clear assessment of outcome measures. The move away from a pre-clinical science grounding, to an integrated 'problem-based learning (PBL) approach' has been widespread in many countries across the world. PURPOSE: One effect of these changes has been the way in which clinical skills, in particular history and examination are taught. By integrating clinical scenarios earlier in the undergraduate course, clinical skills are increasingly taught in tutorials. This approach, when used in the pre-clinical setting may have shortcomings in the development of the ability to construct a differential diagnosis. There has been little evidence that PBL improves problem-solving ability and this is critical to the differential diagnostic process. The concurrent decline in anatomical teaching and understanding contributes to this difficulty. DISCUSSION: The authors outline a model which clinicians can re-emphasize to students and juniors based on the fundamentals of clinical practice. The apprenticeship is more important than ever in the days of small group learning. The relinquishing of the traditional model of undergraduate medicine is of concern. The effects of educational reform should be examined by further research into the competencies of graduates entering higher professional training, before it is accepted that this change has been for the better.

The greater trochanter triangle; a pathoanatomic approach to the diagnosis of chronic, proximal,lateral, lower limb [corrected] pain in athletes.

Chronic pain experienced in the proximal, lateral, lower limb may arise from the femoro-acetabular joint, from the muscles and tendons that act upon it, from any of the structures that traverse the area, and from more remote structures such as the lumbar spine. The aetiology of pathology in this area is not confined to either trauma or overuse. As a result many different sporting activities may have a causal role. Without a clear clinical/pathological diagnosis, the subsequent management of chronic groin pain is difficult. The combination of complex anatomy, variability of presentation and the non-specific nature of the signs and symptoms makes the diagnostic process problematic. The paper proposes a novel educational model based on pathoanatomic concepts. Anatomical reference points were selected to form a triangle, which provides the discriminative power to restrict the differential diagnosis, and form the basis of ensuing investigation. This paper forms part of a series addressing the three-dimensional nature of proximal lower limb pathology. The 3G approach (groin, gluteal, and greater trochanter triangles) acknowledges this, permitting the clinician to move throughout the region, considering pathologies appropriately.

The groin triangle: a patho-anatomical approach to the diagnosis of chronic groin pain in athletes.

Chronic groin pain is a common presentation in sports medicine. It is most often a problem in those sports that involve kicking and twisting movements while running. The morbidity of groin pain should not be underestimated, ranking behind only fracture and anterior cruciate ligament reconstruction in terms of time out of training and play. Due to the insidious onset and course of pathology in the groin region it commonly presents with well-established pathology. Without a clear clinical/pathological diagnosis, the subsequent management of chronic groin pain is difficult. The combination of complex anatomy, variability of presentation and the non-specific nature of the signs and symptoms make the diagnostic process problematical. This paper proposes a novel educational model based on patho-anatomical concepts. Anatomical reference points were selected to form a triangle, which provides the discriminative power to restrict the differential diagnosis and form the basis of ensuing investigation. This paper forms part of a series addressing the three-dimensional nature of proximal lower limb pathology. The 3G approach (groin, gluteal and greater trochanter triangles) acknowledges this, permitting the clinician to move throughout the region, considering pathologies appropriately.

The effect of exercise on motor performance tasks used in the neurological assessment of sports-related concussion.

Sports-related concussion is assessed using both cognitive and motor performance tasks. There is limited understanding of how exercise affects these measures. The purpose of this study was to investigate the effect of moderate-intensity exercise on three selected measures of motor performance. A repeated measures design was used to compare baseline motor performance scores with post-exercise scores with an exercise intervention modelled on the physiological demands of a team sport. 30 physically active subjects performed timed motor performance tasks: Finger-to-Nose (FTN), Tandem Gait (TG) and Single Leg Stance (SLS). The tasks were administered twice pre-exercise and twice post-exercise. FTN, TG and SLS demonstrated high test-retest reliability (ICC values >0.8). 15 minutes of moderate-intensity exercise caused a significant improvement in FTN (T2 = 2.66 (SD 0.38), T3 = 2.49 (0.32); p<0.001) and TG (T2 = 13.08 (2.84), T3 = 12.23 (2.22); p = 0.001), but not in SLS (T2 = 5.94 (4.99), T3 = 5.91 (5.54); p = 0.507). Improvement in the performance of motor tasks after exercise has implications for the immediate assessment of sports-related concussion, given that measures of motor performance are utilised in concussion assessment instruments.

Concussion: the history of clinical and pathophysiological concepts and misconceptions.

Concussion is a well-recognized clinical entity; however, its pathophysiologic basis remains a mystery. One unresolved issue is whether concussion is associated with lesser degrees of diffuse structural change seen in severe traumatic brain injury, or is the mechanism entirely caused by reversible functional changes. This issue is clouded not only by the lack of critical data, but also by confusion in terminology, even in contemporary literature. This confusion began in ancient times when no distinction was made between the transient effects of concussion and severe traumatic brain injury. The first clear separate recognition of concussion was made by the Persian physician, Rhazes, in the 10th century. Lanfrancus subsequently expanded this concept as brain "commotion" in the 13th century, although other Renaissance physicians continued to obscure this concept. By the 18th century, a variety of hypotheses for concussion had emerged. The 19th century discovery of petechial hemorrhagic lesions in severe traumatic brain injury led to these being posited as the basis of concussion, and a similar logic was used later to suggest diffuse axonal injury was responsible. The neuropathology and pathophysiology of concussion has important implications in neurology, sports medicine, medicolegal medicine, and in the understanding of consciousness. Fresh approaches to these questions are needed and modern research tools, including functional imaging and experimental studies of ion-channel function, could help elucidate this puzzle that has evolved over the past 3,000 years.

The nature and duration of acute concussive symptoms in Australian football.

OBJECTIVE: The purpose of this pilot study was to document the nature and temporal profile of the clinical symptoms of acute sport-related concussion. DESIGN: Prospective cohort study PATIENT POPULATION: A total of 303 elite Australian football players participating in a national competition during a single season. OUTCOME MEASURES: Number and duration of symptoms, digit symbol substitution test (DSST) scores, time of return to play post injury. RESULTS: A total of 23 concussions were recorded over the course of the 20-week football season. No catastrophic head injuries occurred. Headache was the most common symptom and the most persistent, with 40% of players reporting headache symptoms lasting more than 15 minutes. Ten of the players (43%) returned to sport on the day of the injury with the remainder resuming play within 2 weeks. A low likelihood of return to play on the day of injury was found where 3 or more symptoms were present or where the symptoms lasted more than 15 minutes. These findings were significantly correlated with poor DSST performance. CONCLUSIONS: This pilot study suggests that both the number of postconcussive symptoms and their duration may be used as a measure of injury severity and a guide for return to play.

Deaths due to brain injury among footballers in Victoria, 1968-1999.

OBJECTIVES: To determine the frequency and nature of fatal brain injuries occurring in Australian football. SETTING: State of Victoria, January to July 1999. DESIGN: Retrospective case series of football-related deaths identified from the coronial autopsy records of the Victorian Institute of Forensic Medicine (1990-1999) and newspaper reports (1968-1989). MAIN OUTCOME MEASURES: Coronial autopsy findings and circumstances of injury. RESULTS: 25 deaths associated with Australian football were identified, nine due to brain injury. Coronial findings in the brain-injury deaths were intracranial haemorrhage in eight patients and infarct in the territory of the middle cerebral artery in one. In three of four cases of subarachnoid haemorrhage, vertebral artery trauma was noted. In all but one case, injury occurred as an accidental part of play. CONCLUSIONS: The most common findings in deaths due to brain injury in Australian football were intracranial haemorrhage, including subarachnoid haemorrhage from vertebral artery injury.

Video analysis of acute motor and convulsive manifestations in sport-related concussion.

OBJECTIVES: To describe the motor and convulsive manifestations in acute sports-related head injury. METHODS: A total of 234 cases of concussive injuries during the 1995 through 1997 football seasons were obtained from the Australian Football League Medical Officers Association injury survey. Of these, 102 cases were recorded adequately on television videotape and were analyzed by two independent observers using a standardized recording form detailing injury mechanics and clinical features of the episodes. Motor and convulsive features were correlated with mechanical variables and with duration of loss of consciousness using linear modeling techniques. RESULTS: Tonic posturing occurred in 25 subjects, clonic movements in 6, righting movement in 40, and gait unsteadiness in 42. In one subject the tonic and clonic features were sufficiently prolonged to be deemed a concussive convulsion. The only risk factor for tonic posturing using logistic regression was the presence of loss of consciousness (p = 0.0001). There was a trend toward facial impact being an independent predictor of tonic posturing but this did not reach significance. No other independent variable predicted the development of clonic movements, righting movements, or gait unsteadiness. CONCLUSIONS: Subtle motor manifestations such as tonic posturing and clonic movements commonly occur in concussion; the main predictive factor for tonic posturing is the presence of loss of consciousness. The authors speculate that these clinical features are due to brainstem dysfunction secondary to biomechanical forces inducing a transient functional decerebration.

Mouthguard use in Australian football.

A survey was performed of 961 Australian rules footballers of varying age and football ability in order to determine the prevalence of mouthguard use during training and match play. Emergency dental injury data was obtained to compare the frequency and timing of dental injury in a non-sporting community population. The prevalence of mouthguard use during match play varied between 60% for juniors and 90% for elite footballers whereas the mouthguard use during training ranged between 2% for junior and 40% for elite players. One third of players used over the counter 'boil & bite' mouthguards, generally considered unsatisfactory for dental protection. Of the players who did not currently use mouthguards, most had tried them previously but found them uncomfortable to wear. The community dental injury data showed that the majority of emergency dental injuries were due to sport and followed the temporal pattern of sports participation on week days and weekends. The prevalence of mouthguard use in this population was not known. This study has implications for the provision of emergency dental treatment for sport participants and for improved dental injury prevention measures to avoid expensive and potentially disfiguring dental injuries in young athletes.

Second impact syndrome.

Diffuse cerebral swelling with delayed catastrophic deterioration, a known complication of brain trauma, has been postulated to occur after repeated concussive brain injury in sports--the "second impact syndrome" (SIS). Certain current concussion management guidelines are contingent upon this assumption. We established criteria for definite, probable, and possible SIS and analyzed all published cases. A total of 17 cases were identified in which the reports described the cases as being consistent with SIS. Of these, only five probable cases of SIS were found based on our diagnostic criteria. We also studied the accuracy of recalled episodes of minor concussion in football players by their teammates because the diagnosis of SIS is usually based on such accounts. We found overreporting of recalled episodes of concussion in teammates when compared with self reports and videotape analysis. Based on case reports, the claim that SIS is a risk factor for diffuse cerebral swelling is not established. Prevention strategies for sports-related cerebral swelling are difficult to implement in the absence of established risk factors.

Concussive convulsions. Incidence in sport and treatment recommendations.

Concussive convulsions (CC) are nonepileptic phenomena which are an immediate sequelae of concussive brain injury. Although uncommon, occurring with an approximate incidence of 1 case per 70 concussions, these episodes are often confused with post-traumatic epilepsy which may occur with more severe structural brain injury. The pathophysiological mechanism of CC remains speculative, but may involve a transient traumatic functional decerebration with loss of cortical inhibition and release of brainstem activity. The phenomenology of the CC is somewhat akin to convulsive syncope, with an initial tonic phase occurring within 2 seconds of impact, followed by a clonic or myoclonic phase which may last several minutes. Lateralising features are common during the convulsions. There is no evidence of structural or permanent brain injury on clinical assessment, neuropsychological testing or neuroimaging studies. Long term outcome is universally good with no evidence of long term epilepsy and athletes are usually able to return to sport within 2 weeks. The correct management of these episodes centres on the appropriate management of the associated concussive injury and the exclusion of other cerebral injury by medical assessment. The CC requires no specific management beyond immediate onfield first aid measures such as protection of the airway. Antiepileptic therapy is not indicated and prolonged absence from sport is unwarranted. These episodes, although dramatic, are relatively straightforward to manage and all team physicians and those involved in athlete care need to be aware of this condition.

Were you knocked out? A team physician's approach to initial concussion management.

To present an evidence-based approach reviewing the acute management of concussive brain injury in sport. All published articles on the acute management of sport-related brain injury were extracted using searches of computerised databases (Medline, Embase, Sport Discus) as well as detailed literature reviews based upon the published bibliographies in this area. The review details the aspects where prospective scientific data is available upon which to base clinical management strategies. The first few minutes after an athlete receives a concussive injury provides a window of opportunity during which time the initial medical management forms a crucial and potentially lifesaving treatment. All clinicians involved in care of the concussed athlete need to have an understanding of the early management of the concussed athlete and a strategy by which they may manage such problems. An efficient and appropriate response to the immediate concussion management will help minimise the potential sequelae which may impact upon the athletes ability to return to sport.

Retrospective study of concussive convulsions in elite Australian rules and rugby league footballers: phenomenology, aetiology, and outcome.

OBJECTIVES: To study the ictal phenomenology, aetiology, and outcome of convulsions occurring within seconds of impact in violent collision sport. DESIGN: Retrospective identification of convulsions associated with concussive brain injury from case records from medical officers of football clubs over a 15 year period. SUBJECTS: Elite Australian rules and rugby league footballers. MAIN OUTCOME MEASURES: Neuroimaging studies, electroencephalography, neuropsychological test data, and statistics on performance in matches to determine presence of structural or functional brain injury. Clinical follow up and electroencephalography for evidence of epilepsy. RESULTS: Twenty two cases of concussive convulsions were identified with four events documented on television videotape. Convulsions began within 2 seconds of impact and comprised an initial period of tonic stiffening followed by myoclonic jerks of all limbs lasting up to 150 seconds. Some asymmetry in the convulsive manifestations was common, and recovery of consciousness was rapid. No structural or permanent brain injury was present on clinical assessment, neuropsychological testing, or neuroimaging studies. All players returned to elite competition within two weeks of the incident. Epilepsy did not develop in any player over a mean (range) follow up of 3.5 (1-13) years. CONCLUSIONS: These concussive or impact convulsions are probably a non-epileptic phenomenon, somewhat akin to convulsive syncope. The mechanism may be a transient traumatic functional decerebration. In concussive convulsions the outcome is universally good, antiepileptic treatment is not indicated, and prolonged absence from sport is unwarranted.