Craig Ranson

The relationship between bowling action classification and three-dimensional lower trunk motion in fast bowlers in cricket

Abstract Lower back injuries, specifically lumbar stress fractures, account for the most lost playing time in professional cricket. The aims of this study were to quantify the proportion of lower trunk motion used during the delivery stride of fast bowling and to examine the relationship between the current fast bowling action classification system and potentially injurious kinematics of the lower trunk. 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. A high percentage of the fast bowlers used a mixed bowling action attributable to having shoulder counter-rotation greater than 30°. The greatest proportion of lower trunk extension (26%), contralateral side-flexion (129%), and ipsilateral rotation (79%) was used during the front foot contact phase of the fast bowling delivery stride. There was no significant difference in the proportions 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. Motion of the lower trunk, particularly side-flexion, during front foot contact, in addition to variables previously known to be related to back injury (e.g. shoulder counter-rotation), should be examined in future cross-sectional and prospective studies examining the fast bowling action and low back injury.

An investigation into the use of MR imaging to determine the functional cross sectional area of lumbar paraspinal muscles.

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.

Magnetic resonance imaging of the lumbar spine in asymptomatic professional fast bowlers in cricket

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.

The Lumbar Paraspinal Muscle Morphometry of Fast Bowlers in Cricket

Objective:To describe the functional cross-sectional area (FCSA) of the lumbar paraspinal muscles of professional fast bowlers in cricket and to investigate the nature of any muscle asymmetry. Design:Descriptive cross-sectional between-groups study. Setting:The England and Wales Cricket Board. Participants:Forty-six asymptomatic professional fast bowlers and 17 athletic controls. Main Outcome Measurements:The magnetic resonance imaging of functional cross-sectional area (FCSA) of the lumbar paraspinal muscles, and the prevalence of asymmetry (greater than 10% difference in the FCSA between the dominant and nondominant side muscles). Results:A relatively high percentage of fast bowlers had asymmetrically larger dominant side quadratus lumborum FCSAs at L1 (47%), L3 (41%), and L4 (47%). The nondominant side psoas FCSA was larger in fast bowlers at L5, and the dominant side multifidus FCSA was larger in both the fast bowlers at L3 to S1 and in the control subjects at L4 and L5. Conclusions:There was a higher prevalence of lumbar muscle asymmetry in the fast bowler group. Paraspinal muscle asymmetry was most prevalent in the quadratus lumborum of fast bowlers, and it was also evident in the lumbar multifidus in both groups of subjects. In both muscle groups, this was consistent with hypertrophy of the dominant side muscle. This study may be used to inform prospective studies of risk factors for low back injury in athletic males and enhance the development of more accurate models of stress production in the lumbar spine during fast bowling and other asymmetrical sports.

Injuries to the lower back in elite fast bowlers: ACUTE STRESS CHANGES ON MRI PREDICT STRESS FRACTURE

In our study, the aims were to describe the changes in the appearance of the lumbar spine on MRI in elite fast bowlers during a follow-up period of one year, and to determine whether these could be used to predict the presence of a stress fracture of the posterior elements. We recruited 28 elite fast bowlers with a mean age of 19 years (16 to 24) who were training and playing competitively at the start of the study. They underwent baseline MRI (season 1) and further scanning (season 2) after one year to assess the appearance of the lumbar intervertebral discs and posterior bony elements. The incidence of low back pain and the amount of playing and training time lost were also recorded. In total, 15 of the 28 participants (53.6%) showed signs of acute bone stress on either the season 1 or season 2 MR scans and there was a strong correlation between these findings and the later development of a stress fracture (p < 0.001). The prevalence of intervertebral disc degeneration was relatively low. There was no relationship between disc degeneration on the season 1 MR scans and subsequent stress fracture. Regular lumbar MR scans of asymptomatic elite fast bowlers may be of value in detecting early changes of bone stress and may allow prompt intervention aimed at preventing a stress fracture and avoiding prolonged absence from cricket.

Shoulder injury in professional cricketers

OBJECTIVE To describe the impact of shoulder injuries on professional cricketers during the 2005 England and Wales first class cricket season. DESIGN Professional cricketers in England were asked to complete two questionnaires relating to shoulder injuries. Players who returned both questionnaires were included in this study. MAIN OUTCOME MEASUREMENTS The impact of any shoulder pain whilst playing cricket, impaired cricketing performance and shoulder injury related problems during training and activities of daily living. RESULTS One hundred and fifty eight of a total of 378 players (42%) returned both questionnaires. Twenty-three per cent of the participants described shoulder injury during the 2005 season. Injury prevalence (the percentage of players not available for selection in a match due to shoulder injury) was 1.7%. Sixty-four per cent of shoulder injured players often or always had associated problems when fielding, and 58% of shoulder injured players fielded in a specific position to avoid shoulder injury related problems. Eighteen per cent of all study participants felt pain on throwing at some stage during the survey period. CONCLUSIONS Professional cricketers generally play on with shoulder injuries without missing matches, though their performance, especially during fielding, is often compromised. Research into the diagnoses, aetiology, appropriate treatment and prevention of shoulder injuries in cricket is required.

The influence of cricket fast bowlers’ front leg technique on peak ground reaction forces

Abstract High ground reaction forces during the front foot contact phase of the bowling action are believed to be a major contributor to the high prevalence of lumbar stress fractures in fast bowlers. This study aimed to investigate the influence of front leg technique on peak ground reaction forces during the delivery stride. Three-dimensional kinematic data and ground reaction forces during the front foot contact phase were captured for 20 elite male fast bowlers. Eight kinematic parameters were determined for each performance, describing run-up speed and front leg technique, in addition to peak force and time to peak force in the vertical and horizontal directions. There were substantial variations between bowlers in both peak forces (vertical 6.7 ± 1.4 body weights; horizontal (braking) 4.5 ± 0.8 body weights) and times to peak force (vertical 0.03 ± 0.01 s; horizontal 0.03 ± 0.01 s). These differences were found to be linked to the orientation of the front leg at the instant of front foot contact. In particular, a larger plant angle and a heel strike technique were associated with lower peak forces and longer times to peak force during the front foot contact phase, which may help reduce the likelihood of lower back injuries.

International cricket injury surveillance: a report of five teams competing in the ICC Cricket World Cup 2011

Background Injury surveillance is the cornerstone of effective injury management. However, to date no studies using recommended methods and involving multiple nations have been conducted within International Cricket. Aim To conduct injury surveillance across multiple teams during the ICC Cricket World Cup 2011. Methods An electronic system, based on the guidelines for injury surveillance in international cricket, was used to record all new injury episodes was used for data collection. Results Twenty-three time-loss and 97 non-time-loss injuries were recorded. The injury incidence was 3.7/100 player-days (0.7 time-loss and 3.0 non-time-loss) with time-loss incidence being; for match injury 20.1/1000 player-days, bowling injury 3.3/100 bowling days and batting injuries 2.2/10 000 balls faced. Thigh muscle strain and medical illness were the diagnoses with the highest incidence. Fast bowlers, slow bowlers and batters all had a similar injury prevalence of approximately 5%. The bowling delivery stride was the activity that resulted in the greatest lost time. Conclusions This is the first study to use recommended injury surveillance guidelines to reporting injury rates across multiple teams at a major cricket tournament. Non-time-loss injury incidence appears relatively high and further study of the effect on performance and progression to subsequent time-loss is required. Fast bowler injury prevalence rates are lower than reported elsewhere, however this may be due to the nature of the tournament and match format, which is likely to impose a lower relative workload. In future, data from all competing teams over all formats of the game (Twenty20, ODI and Tests) needs to be analysed to effectively inform injury prevention research and practice.

International consensus statement on injury surveillance in cricket: a 2016 update

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.

Injury Risk in International Rugby Union Three-Year Injury Surveillance of the Welsh National Team

Background: Within international Rugby Union, only injury rates during the Rugby World Cup have been reported. Therefore, injury rates and types during other international tournaments are unknown. Purpose: To assess the 3-year incidence, severity, nature, and causes of match and training injuries sustained during different international tournaments played by the Welsh national Rugby Union team. Study Design: Descriptive epidemiology study. Methods: Injury data for all players (n = 78) selected for 1 national Rugby Union team over a 3-year period were analyzed using the international consensus statement methods. Player height (cm) and mass (kg) were recorded. Tournaments were grouped for comparisons as: autumn tournaments (2012 and 2013), Rugby World Cup (RWC; 2011), Six Nations (2012, 2013, and 2014), and summer tournaments (2012, 2013, and 2014). Injury incidence (injuries/1000 hours), prevalence (% of players unavailable), and severity (days lost) were calculated for each tournament. Injury location, type, and cause of match and training injuries were analyzed. Results: Match injury incidence was highest during autumn tournaments (262.5/1000 match-hours) and lowest during the RWC (178.6/1000 match-hours). Summer tournaments had the highest training incidence (5.5 injuries/1000 training-hours). Mild injuries were most likely during the RWC (risk ratio [RR], 2.02; 95% CI, 1.26-3.24), while severe injuries were most likely during autumn tournaments (RR, 3.27; 95% CI, 1.70-6.29). Quadriceps hematomas (18.8/1000 match-hours; 95% CI, 11.3-31.1) and concussions (13.8/1000 match-hours; 95% CI, 7.6-24.8) were the most common match injuries, with shoulder dislocations being the most severe (111 mean days lost per injury). Conclusion: Injury rates were considerably higher than those previously reported for multiple teams during RWC tournaments. Further investigation of injury rates and risk factors is recommended to accurately gauge their impact within international Rugby Union, particularly with regard to lower limb hematoma, concussion, and shoulder injuries.