Correlating clinical assessment and MRI findings in diagnosing calf injuries in elite male Australian rules footballers.

OBJECTIVE: Calf complex injuries represent a significant injury burden among Australian Rules athletes. To date, there has been limited research correlating clinical and radiological findings of pathology within the calf. The objective of this study is to determine how accurately magnetic resonance imaging (MRI) findings correlate with clinical measures of calf muscle complex pathology in elite male athletes. MATERIALS AND METHODS: A prospective cohort study was conducted on Australian rules elite athletes. A cohort of 45 athletes underwent a high-load training session of approximately 10 km of running. Athletes were then assessed by a sports physiotherapist who made a diagnosis of no pathology, delayed onset muscle soreness, strain or other. Subsequently, the athletes underwent MRI of their bilateral calf complexes. Radiologists interpreted the MRI findings and radiological diagnosis were correlated with clinical diagnosis. RESULTS: A total of 90 calf MRIs were performed. Correlation of clinical and radiological diagnosis occurred in 57 cases. Of the 33 cases which did not correlate, there were 4 radiologically significant acute calf strains in clinically asymptomatic athletes, 3 of which involved old scar tissue. CONCLUSION: MRI may detect clinically insignificant injuries within the calf complex. If an athlete does not have any clinically relevant symptoms, abnormal signal on MRI may represent a different diagnosis to muscle strain. Signal change on MRI proximal to scar tissue may represent reactive oedema. Clinical history and examination should be correlated with radiological findings is recommended when diagnosing calf injury in elite athletes.

An assessment of the utility and functionality of wearable head impact sensors in Australian Football.

OBJECTIVES: To assess the utility and functionality of the X-Patch® as a measurement tool to study head impact exposure in Australian Football. Accuracy, precision, reliability and validity were examined. DESIGNS: Laboratory tests and prospective observational study. METHODS: Laboratory tests on X-Patch® were undertaken using an instrumented Hybrid III head and neck and linear impactor. Differences between X-Patch® and reference data were analysed. Australian Football players wore the X-Patch® devices and games were video-recorded. Video recordings were analysed qualitatively for head impact events and these were correlated with X-Patch® head acceleration events. Wearability of the X-Patch® was assessed using the Comfort Rating Scale for Wearable Computers. RESULTS: Laboratory head impacts, performed at multiple impact sites and velocities, identified significant correlations between headform-measured and device-measured kinematic parameters (p<0.05 for all). On average, the X-Patch®-recorded peak linear acceleration (PLA) was 17% greater than the reference PLA, 28% less for peak rotational acceleration (PRA) and 101% greater for the Head Injury Criterion (HIC). For video analysis, 118 head acceleration events (HAE) were included with PLA ≥30g across 53 players. Video recordings of X-Patch®-measured HAEs (PLA ≥30g) determined that 31.4% were direct head impacts, 9.3% were indirect impacts, 44.1% were unknown or unclear and 15.3% were neither direct nor indirect head impacts. The X-Patch® system was deemed wearable by 95-100% of respondents. CONCLUSIONS: This study reinforces evidence that use of the current X-Patch® devices should be limited to research only and in conjunction with video analysis.

Accelerometers for the Assessment of Concussion in Male Athletes: A Systematic Review and Meta-Analysis.

BACKGROUND: Concussion is common in the sporting arena and is often challenging to diagnose. The development of wearable head impact measurement systems has enabled measurement of head kinematics in contact sports. OBJECTIVES: The objective of this systematic review was to determine the characteristics of head kinematics measured by an accelerometer system among male athletes diagnosed with concussion. METHODS: A systematic search was conducted in July 2015. Inclusion criteria were English-language studies published after 1990 with a study population of male athletes, in any sport, where objectively measured biomechanical forces were reported in the setting of a concussive event. The random effects meta-analysis model was used to combine estimates of biomechanical force measurements in concussed athletes. RESULTS: Thirteen studies met the inclusion criteria, the majority of which were conducted with high school and college football teams in the US. Included studies measured a combination of linear and rotational acceleration. The meta-analysed mean peak linear head acceleration associated with a concussive episode was 98.68 g (95 % CI 82.36-115.00) and mean peak rotational head acceleration was 5776.60 rads/s2 (95 % CI 4583.53-6969.67). The estimates of the biomechanical forces were consistent across studies, with I 2 values of 0 % for both meta-analyses. CONCLUSIONS: Head impact monitoring through accelerometery has been shown to be useful with regard to characterising the kinematic load to the head associated with concussion. Future research with improved clinical outcome measures and head kinematic data may improve accuracy when evaluating concussion, and may assist with both interpretation of biomechanical data and the development and utilisation of implementation strategies for the technology.