The association between hip and groin injuries in the elite junior football years and injuries sustained during elite senior competition.

OBJECTIVE: To establish the relationship between the history of hip and groin injuries in elite junior football players prior to elite club recruitment and the incidence of hip and groin injuries during their elite career. DESIGN: Retrospective cohort study. SETTING: Analysis of existing data. PARTICIPANTS: 500 Australian Football League (AFL) players drafted from 1999 to 2006 with complete draft medical assessment data. ASSESSMENT OF RISK FACTORS: Previous history of hip/groin injury, anthropometric and demographic information. MAIN OUTCOME MEASUREMENT: The number of hip/groin injuries resulting in > or =1 missed AFL game. RESULTS: Data for 500 players were available for analysis. 86 (17%) players reported a hip/groin injury in their junior football years. 159 (32%) players sustained a hip/groin injury in the AFL. Players who reported a previous hip or groin injury at the draft medical assessment demonstrated a rate of hip/groin injury in the AFL >6 times higher (IRR 6.24, 95% CI 4.43 to 8.77) than players without a pre-AFL hip or groin injury history. CONCLUSIONS: This study demonstrated that a hip or groin injury sustained during junior football years is a significant predictor of missed game time at the elite level due to hip/groin injury. The elite junior football period should be targeted for research to investigate and identify modifiable risk factors for the development of hip/groin injuries.

Is the simple versus complex classification of concussion a valid and useful differentiation?

BACKGROUND: At the Second International Conference on Concussion in Sport, concussion was classified as "simple" or "complex" based largely on duration of clinical features. The purpose of the classification system was to assist clinicians in identifying higher grades of injury severity and guide injury management. The aim of the current paper is to review the validity and clinical usefulness of the simple versus complex classification system. STUDY DESIGN: Qualitative review of the literature on concussion in sport, with a focus on time course of clinical recovery and prognostic factors. INTERVENTION: Pubmed, Medline and Sport Discus databases were reviewed. Fifty journal articles were included in the review. RESULTS: Prospective studies support the recovery of symptoms, balance deficits and cognitive impairment in the majority of concussed athletes within 10 days of injury. However, clinical factors that predict higher grades of injury severity or poor outcome following concussion remain unclear. At present, concussion severity can only be accurately determined in retrospect after all clinical features have resolved. CONCLUSION: It is recommended that concussion in sport be considered as a single entity. Clinical factors that have demonstrated to be associated with longer duration of symptoms (for example, post-traumatic amnesia) or poor outcome (for example, repetitive head injury) may serve as "modifying" factors to assist the treating practitioner in identifying potential for higher grades of injury severity or adverse outcomes.

Teaching landing skills in elite junior Australian football: evaluation of an injury prevention strategy.

OBJECTIVE: To evaluate the effectiveness of a preseason physical training programme that taught landing and falling skills in improving landing skills technique and preventing injury in junior elite Australian football players. METHODS: 723 male players who participated in an under 18 elite competition were studied prospectively in a non-randomised controlled trial over two consecutive football seasons. There were 114 players in the intervention group and 609 control players. The eight session intervention programme taught players six landing, falling, and recovery skills, which were considered fundamental for safe landing in Australian football. Landing skills taught in these sessions were rated for competence by independent and blinded assessors at baseline and mid-season. RESULTS: Evaluation of landing skills found no significant differences between the groups at baseline. Evaluation after the intervention revealed overall improvement in landing skills, but significantly greater improvement in the intervention group (z = -7.92, p = 0.001). Players in the intervention group were significantly less likely (relative rate 0.72, 95% confidence interval 0.52 to 0.98) to sustain an injury during the season than the control group. In particular, the time to sustaining a landing injury was significantly less for the intervention group (relative rate 0.40, 95% confidence interval 0.17 to 0.92) compared with the control group. CONCLUSIONS: Landing and falling ability can be taught to junior elite Australian football players. Players in the intervention group were protected against injury, particularly injuries related to landing and falls.

Does history of concussion affect current cognitive status?

The association between self reported history of concussion and current neurocognitive status is controversial. Some football studies suggest that athletes with a history of concussion display cognitive impairment relative to athletes with no history of concussion, but other studies have not been able to reproduce such findings. This study shows that there is no relation between the number of previous self reported episodes of concussion and current cognitive state, directly contradicting the findings of previous research.

Navicular stress fractures: outcomes of surgical and conservative management.

OBJECTIVE: To compare the long term outcomes of the two treatment options for navicular stress fractures: non-weightbearing cast immobilisation and surgical fixation. DESIGN: Retrospective case study. PARTICIPANTS: Subjects aged 18 years and older who had been treated for a navicular stress fracture more than two years previously. MAIN OUTCOME MEASURES: Questionnaire based analogue pain score and function score; tenderness on palpation; abnormality detected on computed tomography (CT). RESULTS: In all, 32 fractures in 26 subjects were investigated. No significant differences were found between surgical and conservative management for current pain (p = 0.984), current function (p = 0.170), or abnormality on CT (p = 0.173). However, surgically treated patients more often remained tender over the "N spot" (p = 0.005), even after returning to competition for two years or more. CONCLUSIONS: Surgical fixation of navicular stress fractures appears to be as effective as conservative management over the longer term. However, there remains a small but measurable degree of pain and loss of function over this period. The value of using "N spot" tenderness as the sole clinical predictor of treatment success requires further investigation, as some patients remained tender despite successful completion of treatment and return to competition.

Cognition in the days following concussion: comparison of symptomatic versus asymptomatic athletes.

BACKGROUND: Concussion is a common neurological injury occurring during contact sport. Current guidelines recommend that no athlete should return to play while symptomatic or displaying cognitive dysfunction. This study compared post-concussion cognitive function in recently concussed athletes who were symptomatic/asymptomatic at the time of assessment with that of non-injured (control) athletes. METHODS: Prospective study of 615 male Australian Rules footballers. Before the season, all participants (while healthy) completed a battery of baseline computerised (CogSport) and paper and pencil cognitive tasks. Sixty one injured athletes (symptomatic = 25 and asymptomatic = 36) were reassessed within 11 days of being concussed; 84 controls were also reassessed. The serial cognitive function of the three groups was compared using analysis of variance. RESULTS: The performance of the symptomatic group declined at the post-concussion assessment on computerised tests of simple, choice, and complex reaction times compared with the asymptomatic and control groups. The magnitude of changes was large according to conventional statistical criteria. On paper and pencil tests, the symptomatic group displayed no change at reassessment, whereas large improvements were seen in the other two groups. CONCLUSION: Injured athletes experiencing symptoms of concussion displayed impaired motor function and attention, although their learning and memory were preserved. These athletes displayed no change in performance on paper and pencil tests in contrast with the improvement observed in asymptomatic and non-injured athletes. Athletes experiencing symptoms of concussion should be withheld from training and competition until both symptoms and cognitive dysfunction have resolved.

Value of neuropsychological testing after head injuries in football.

This paper reviews the pros and cons of the traditional paper and pencil and the newer computerised neuropsychological tests in the management of sports concussion. The differences between diagnosing concussion on the field and neuropsychological assessment at follow up and decision making with regard to return to play are described. The authors also discuss the issues involved in interpreting the results of neuropsychological testing (comparison with population norms versus player's own baseline test results) and potential problems of such testing in football. Finally, suggested recommendations for neuropsychological testing in football are given.

Statistical procedures for determining the extent of cognitive change following concussion.

Neuropsychological (NP) testing is now often used to help to determine if the cognitive function of a concussed athlete has declined. The NP test score after concussion is compared with the baseline test score. Many clinicians simply subtract one from the other and make a clinical decision about the significance or otherwise of the resulting "difference score". Such techniques are inadequate, as they fail to account for the many factors that may confound interpretation of serially acquired cognitive test scores. This is a review of a number of alternative approaches used in other areas of medicine for differentiating "true" changes from changes caused by these confounding factors. A case example is used to illustrate the effect that the statistical approach may have on clinical decision making.

Computerised cognitive assessment of concussed Australian Rules footballers.

BACKGROUND: "Paper and pencil" neuropsychological tests play an important role in the management of sports related concussions. They provide objective information on the athlete's cognitive function and thus facilitate decisions on safe return to sport. It has been proposed that computerised cognitive tests have many advantages over such conventional tests, but their role in this domain is yet to be established. OBJECTIVES: To measure cognitive impairment after concussion in a case series of concussed Australian Rules footballers, using both computerised and paper and pencil neuropsychological tests. To investigate the role of computerised cognitive tests in the assessment and follow up of sports related concussions. METHODS: Baseline measures on the Digit Symbol Substitution Test (DSST), Trail Making Test-Part B (TMT), and a simple reaction time (SRT) test from a computerised cognitive test battery (CogState) were obtained in 240 players. Tests were repeated in players who had sustained a concussive injury. A group of non-injured players were used as matched controls. RESULTS: Six concussions were observed over a period of nine weeks. At the follow up, DSST and TMT scores did not significantly differ from baseline scores in both control and concussed groups. However, analysis of the SRT data showed an increase in response variability and latency after concussion in the injured athletes. This was in contrast with a decrease in response variability and no change in latency on follow up of the control players (p<0.02). CONCLUSION: Increased variability in response time may be an important cognitive deficit after concussion. This has implications for consistency of an athlete's performance after injury, as well as for tests used in clinical assessment and follow up of head injuries.

Perindopril treatment prevents the loss of endothelial nitric oxide function and development of neo-intima in rabbits.

An atheroma-like neo-intima was produced by positioning a flexible collar around the common carotid arteries of normocholesterolaemic rabbits. Vessel segments taken from the mid-region of the collared and control region of the same artery were studied 7 days after surgery. Placebo rabbits were provided ab libitum with regular tap water, and treated animals were supplied with water containing perindopril (0.3 mg/kg/day) for 14 days. Perindopril treatment reduced plasma angiotensin converting enzyme (ACE) activity by 88%, but did not significantly alter arterial blood pressure or heart rate. In control rings from placebo rabbits perindoprilat in vitro (0.1-1.0 microM) reduced the sensitivity to angiotension I up to 20-fold but did not affect that of angiotensin II. In placebo rabbits, the collared arterial segments were approximately five-fold more sensitive to the vasoconstrictor action of 5-HT (P < 0.05) than the corresponding control segments. Perindopril treatment did not prevent the supersensitivity of the collared vessels to 5-HT. Development of the lesion in placebo or perindopril-treated rabbits did not alter the vascular sensitivity to either angiotensin I (10(-9)-10(-5)M) or angiotensin II (10(-10)-10(-6)M). The vasorelaxant action of sodium nitroprusside was similar in collared and control rings, whereas the maximum endothelium-dependent vasorelaxant response to acetylcholine was reduced from 68 +/- 5% in control rings, to 44 +/- 8% (mean +/- S.E.M., n = 9, P < 0.05) in collared rings of placebo-treated rabbits. In the perindopril-treated animals, this impairment of relaxation was restored in collared vessels and was no longer significantly different from the control sections. In contrast, perindoprilat in vitro (1.0 microM) did not alter the vasorelaxant response to acetylcholine in control or collared rings in a separate series of placebo rabbits. Morphologically, vessel segments taken from the centre of the collared artery of all placebo rabbits showed a thickened intima filled with cells that had the appearance of synthetic-state smooth muscle. The intimal/medial cross-sectional area ratio was reduced from 0.11 +/- 0.02 (n = 10) in placebo rabbits to 0.05 +/- 0.01 (n = 9) in perindopril-treated rabbits, whereas cross-sectional area of media of the collared vessels was similar in the two groups. Thus ACE may have important roles in the initiation and progression of atheroma-like lesions. Inhibition of ACE with perindopril reduces intimal thickening and restores the defective vasodilatation induced by the endothelial-dependent vasodilator, acetylcholine.

Angiotensin-converting enzyme inhibitors reduce neointimal thickening and maintain endothelial nitric oxide function in rabbit carotid arteries.

Application of periarterial collars induced atheroma-like lesions in the carotid arteries of normocholesterolemic rabbits. Vessel segments taken from the mid-region of the collar (cuffed region) and control regions of the same artery were studied at 7 days after surgery. A group of placebo rabbits was provided ad libitum with regular tap water, and treated animals were supplied for 14 days (beginning 7 days before collar application) with water containing perindopril (daily intake of approximately 0.3 mg/kg). Perindopril treatment reduced plasma angiotensin-converting enzyme (ACE) activity by 88% but did not significantly alter arterial blood pressure or heart rate. The sensitivity of arterial rings to angiotensins I and II did not differ between control and cuffed arteries in either placebo or perindopril-treated rabbits, but in rings from both groups of rabbits the sensitivity to the vasoconstrictor action of serotonin was higher in the cuffed segments, as in previous studies. In addition, in placebo rabbits the endothelium-dependent vasorelaxant response to acetylcholine (which results from the release of nitric oxide) was weaker in cuffed arteries than in controls, whereas in the perindopril-treated animals, this impairment of relaxation was restored to the extent that, in cuffed vessels, it was no longer significantly different from the controls. Similar results were obtained in rabbits treated with another ACE inhibitor (ramipril). In contrast, acute treatment with the metabolite, perindoprilat, in vitro (1.0 microM) did not alter the response to acetylcholine in control or cuffed rings from placebo rabbits. Morphologically, vessel segments taken from the center of the cuffed artery of placebo rabbits showed a thickened intima with marked smooth muscle cell proliferation.(ABSTRACT TRUNCATED AT 250 WORDS)