Cricket was the first sport to publish recommended methods for injury surveillance in 2005. Since then, there have been changes to the nature of both cricket and injury surveillance. Researchers representing the major cricket playing nations met to propose changes to the previous recommendations, with an agreed voting block of 14. It was decided that 10 of 14 votes (70%) were required to add a new definition element and 11 of 14 (80%) were required to amend a previous definition. In addition to the previously agreed ‘Match time-loss’ injury, definitions of ‘General time-loss’, ‘Medical presentation’, ‘Player-reported’ and ‘Imaging-abnormality’ injuries are now provided. Further, new injury incidence units of match injuries per 1000 player days, and annual injuries per 100 players per year are recommended. There was a shift towards recommending a greater number of possible definitions, due to differing contexts and foci of cricket research (eg, professional vs amateur; injury surveillance systems vs specific injury category studies). It is recommended that researchers use and report as many of the definitions as possible to assist both comparisons between studies within cricket and with those from other sports.

Citation: WORTHINGTON, P.J., KING, M.A. and RANSON, C.A., 2013. Relationships between fast bowling technique and ball release speed in cricket.Journal of Applied Biomechanics, 29 (1) The aim of this study was to identify the key aspects of technique that characterize the fastest bowlers. Kinematic data were collected for 20 elite male fast bowlers with 11 kinematic parameters calculated, describing elements of fast bowling technique that have previously been linked to ball release speed. Four technique variables were identified as being the best predictors of ball release speed, explaining 74% of the observed variation in ball release speed. The results indicate that the fastest bowlers have a quicker run-up and maintain a straighter knee throughout the front foot contact phase. The fastest bowlers were also observed to exhibit larger amounts of upper trunk flexion up to ball release and to delay the onset of arm circumduction. This study identifies those technique variables that best explain the differences in release speeds among fast bowlers. These results are likely to be useful in both the coaching and talent identification of fast bowlers.

The purpose of this study was to investigate the use of magnetic resonance (MR) imaging and image processing software to determine the functional cross-sectional area (FCSA) (the area of muscle isolated from fat) of the lumbar paraspinal muscles. The measurement of the morphology of the lumbar paraspinal muscles has become the focus of several recent investigations into the aetiology of low back pain. However, the reliability and validity of determining the FCSA of the lumbar paraspinal muscles using MR imaging are yet to be reported. T2 axial MR scans at the L1-S1 spinal levels of six subjects were obtained using identical MR systems and scanning parameters. Lean paraspinal muscle, vertebral body bone and intermuscular fat were manually segmented using image analysis software to assign a grey scale range to the MR signal intensity emitted by each tissue type. The resultant grey scale range for muscle was used to determine FCSA measurements for each of the paraspinal muscles, psoas, quadratus lumborum, erector spinae and lumbar multifidus on each scan slice. As various biological, instrument and measurement factors can affect MR signal intensity, a sensitivity analysis was conducted to determine the error associated in calculating FCSA for paraspinal muscle using a discrete grey scale range. Cross-sectional area and FCSA measurements were repeated three times and reliability indices for the FCSA measurements were obtained, showing excellent reliability, intra class correlation coefficient (mean=0.97, range 0.90-0.99) and %SEM (mean=2.6%, range 0.7-4.8%). In addition, the error associated with miscalculation of the grey scale range for the MR signal intensity of muscle was calculated and found to be low with an error of 20 grey scale units at the upper end of the muscle's grey scale range resulting in a very small error in the measured muscle FCSA. The method presented in this paper has a variety of practical applications in areas such as evidence-based rehabilitation, biomechanical modelling and the determination of segmental inertial parameters.

The relationship between bowling action classification and three-dimensional lower his item ws sumitted to voughorough niversity9s snstitutionl epository y theGn uthorF Citation: exyxD gFeF FFF et lFD PHHVF he reltionship etween owling tion lssifition nd threeEdimensionl lowerF tournl of ports ienesD PT @QAD ppF PTUEPUTF Additional Information:• his rtile ws pulished in the tournl of ports ienes ylor 8 prnis nd the definitive version is ville tX httpXGGwwwFinformworldFomGsmppGontent £ dallcontentaIHFIHVHGHPTRHRIHUHISHITUI AbstractLower back injuries, specifically lumbar stress fractures, account for the most lost playing time in professional cricket. The aim of this study was to investigate the relationship between the current fast bowling action classification system and potentially injurious kinematics of the lower trunk during fast bowling. Three-dimensional kinematic data were collected from 50 male professional fast bowlers during a standing active range of motion trial and three fast bowling trials. Seventyfour percent of the fast bowlers used a mixed bowling action attributable to having shoulder counter-rotation greater than 30°. There was no difference in the proportion of available lower trunk extension, contralateral side-flexion and ipsilateral rotation range of motion used during fast bowling by mixed and non-mixed action bowlers. The greatest proportion of lower trunk extension (26%), contralateral side-flexion (131%) and ipsilateral rotation (79%) was utilised during the front-foot contact phase of the fast bowling delivery stride. It is proposed that the combination of end range lower trunk positioning, especially side-flexion, and high ground reaction (compressive) forces during the front foot contact phase are the most important pathomechanical factors in the typical pattern of contralateral side lumbar stress injuries seen in this population.

Interventions that reduce the speed and acceleration of the tackler and reduce exposure to head-to-head contact would likely reduce concussion risk in professional rugby union.

ObjectivesTo report COVID-19 illness pattern, symptom duration and time loss in UK elite athletes.MethodsObservational, clinical and database review of athletes with symptomatic COVID-19 illness managed within the UK Sports Institutes. Athletes were classified as confirmed (positive SARS-CoV-2 PCR or antibody tests) or probable (consistent clinical features) COVID-19. Clinical presentation was characterised by the predominant symptom focus (eg, upper or lower respiratory illness). Time loss was defined as days unavailable for full sport participation and comparison was made with a 2016–2019 respiratory illness dataset from the same surveillance system.ResultsBetween 24 February 2020 and 18 January 2021, 147 athletes (25 Paralympic (17%)) with mean (SD) age 24.7 (5.2) years, 37% female, were diagnosed with COVID-19 (76 probable, 71 confirmed). Fatigue was the most prevalent symptom (57%), followed by dry cough (50%) and headache (46%). The median (IQR) symptom duration was 10 (6–17) days but 14% reported symptoms >28 days. Median time loss was 18 (12–30) days, with 27% not fully available >28 days from initial date of infection. This was greater than our historical non-COVID respiratory illness comparator; 6 days, 0–7 days (p<0.001) and 4% unavailable at 28 days. A lower respiratory phenotype (ie, including dyspnoea±chest pain±cough±fever) was present in 18% and associated with a higher relative risk of prolonged symptoms risk ratio 3.0 (95% CI: 1.4 to 6.5) and time loss 2.1 (95% CI: 1.2 to 3.5).ConclusionsIn this cohort, COVID-19 largely resulted in a mild, self-limiting illness. The presence of lower respiratory tract features was associated with prolonged illness and a delayed return to sport.

Low back injuries account for the greatest loss of playing time for professional fast bowlers in cricket. Previous radiological studies have shown a high prevalence of degeneration of the lumbar discs and stress injuries of the pars interarticularis in elite junior fast bowlers. We have examined MRI appearance of the lumbar spines of 36 asymptomatic professional fast bowlers and 17 active control subjects. The fast bowlers had a relatively high prevalence of multi-level degeneration of the lumbar discs and a unique pattern of stress lesions of the pars interarticularis on the non-dominant side. The systems which have been used to classify the MR appearance of the lumbar discs and pars were found to be reliable. However, the relationship between the radiological findings, pain and dysfunction remains unclear.

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