Management of lumbar bone stress injury in cricket fast bowlers and other athletes.

Background: Recent guidelines (including a special series in The Lancet) have emphasised a minimal role for imaging when assessing low back pain in adults, as the majority of patients will have non-specific findings on imaging that do not correlate well with pain. Objective: To assess whether the diagnosis of lumbar bone stress injuries in young athletes should be considered an exception to the recommendation to avoid imaging for low back pain in adults. Method: Narrative review. Results: Early lumbar bone stress injury diagnosis has been available via traditional MRI sequences (and its precursor Single Photon Emission Computed Tomography (SPECT)) for 25-30 years. MRI assessments using bone window sequences (such as Volumetric Interpolated Breath-hold Examination (VIBE)) have allowed a better understanding of the diagnosis and prognosis of lumbar bone stress injury in young athletes. MRI with bone sequences has allowed non-radiating scans to serially follow the healing of unilateral stress fractures. In the majority of cases, non-chronic unilateral fractures can heal; however, this takes three-six months rather than the six-ten weeks that would be the typical unloading period if using symptoms (only) as a guide. The use of MRI to provide evidence of bony healing (as opposed to fibrous union, which creates the pars defect that predisposes to further bone stress lesions) can lead to better long-term outcomes in athletes. There is evidence to flag this as a structural lesion which is both painful and, more importantly, can heal/resolve if managed correctly. Therefore it represents an important 'specific' diagnostic subset within adult low back pain. Conclusion: Structural (rather than functional) management of bone stress injuries in high-demand athletes, such as cricket pace bowlers, is in contrast to the recommendation of functional management for general back pain in adults. Structural management is justified when there are demonstrable superior outcomes of having better structure. Although this has not yet been shown in randomised trials of elite athletes, apparent lengthier Test cricket careers of pace bowlers who do not have pars defects suggest better athletic outcomes if bony healing is achieved. For lower demand young adults, or athletes with established bilateral pars defects, functional management may be more pragmatic.

Is bowling workload a risk factor for injury to Australian junior cricket fast bowlers?

OBJECTIVES: To examine whether bowling workload is a risk factor for overuse injury to Australian junior cricket fast bowlers and to evaluate the appropriateness of current bowling workload guidelines. METHODS: Forty four male fast bowlers (mean (standard deviation) age 14.7 (1.4) years) were monitored prospectively over the 2002-2003 season. Bowlers completed a daily diary to record bowling workloads and self reported injuries, which were validated by a physiotherapist. Bowling workload prior to the first injury (for those bowlers who were injured) was compared to workload across the whole season for uninjured bowlers. RESULTS: Eleven (25%) bowlers reported an overuse-type injury, with seven of these sustaining a back injury. Injured bowlers had been bowling significantly more frequently than uninjured bowlers (median number of days since the previous bowling day: 3.2 v 3.9 days, Mann-Whitney U = 105.0, p = 0.038). Compared with bowlers with an average of > or =3.5 rest days between bowling, bowlers with an average of <3.5 rest days were at a significantly increased risk of injury (risk ratio (RR) = 3.1, 95% confidence interval (CI) 1.1 to 8.9). There were also trends towards an increased risk of injury for those who bowled an average of > or =2.5 days per week (RR = 2.5, 95% CI 0.9 to 7.4) or > or =50 deliveries per day (RR = 2.0, 95% CI 0.7 to 5.4). CONCLUSIONS: This study has identified high bowling workload as a risk factor for overuse injury to junior fast bowlers. Continued research is required to provide scientific evidence for bowling workload guidelines that are age-specific for junior fast bowlers.

The relationship between fast bowling workload and injury in first-class cricketers: a pilot study.

This study examined the relationship between the bowling workload of first-class fast bowlers and injury with the aim of identifying a "safe" fast bowling workload threshold. Twelve male fast bowlers (mean age 25 years) from an Australian state cricket squad were observed for the 1999--2000 cricket season. Workload was quantified by examining fixture scorecards and conducting surveillance at training sessions. Injury data were obtained from Cricket Australia's Injury Surveillance System. The seasonal incidence of injury was high with seven bowlers sustaining nine injuries. Whilst injured bowlers did not tend to bowl a greater number of deliveries on the day of injury, a significant increase in deliveries per session was observed in the 8-21 days prior to the date of injury (mean= 77) as compared with the rest of the season (mean= 60, p< 0.02). Bowlers with a weekly bowling workload above the mean of 203 deliveries were at an increased risk of injury (Risk Ratio (RR)= 6.0, 95% confidence interval (CI) 1.00-35.91). Those bowlers who bowled in five or more sessions in any 7-day period were also at an increased risk of injury (RR= 4.5, 95% CI 1.02 to 20.12). A consistent relationship between high bowling workload and injury was observed. The risk of injury was much higher for those bowlers with a sessional, weekly and monthly bowling workload above the group mean, especially when this high workload was consistent and sustained.

Lumbar spine region pathology and hamstring and calf injuries in athletes: is there a connection?

This paper discusses the theory that subtle lumbosacral canal impingement of the L5 nerve root may be a relatively common occurrence in older footballers and may in fact be a common underlying basis for the age related predisposition towards hamstring and calf strains.

Bowling workload and the risk of injury in elite cricket fast bowlers.

This study examined the relationship between the bowling workload of first-class cricket fast bowlers and injury with the aim of identifying a workload threshold at which point the risk of injury increases. Ninety male fast bowlers (mean age 27 years, range 18-38 years) from six Australian state squads were observed for the 2000-2001 and/or 2001-2002 cricket seasons. Workload was quantified by examining fixture scorecards and conducting surveillance at training sessions. Injury data was obtained from the Cricket Australia's Injury Surveillance System. Compared to bowlers with an average of 3-3.99 days between bowling sessions, bowlers with an average of less than 2 days (risk ratio (RR) = 2.4, 95% confidence interval (CI) 1.6 to 3.5) or 5 or more days between sessions (RR = 1.8, 95% CI 1.1 to 2.9) were at a significantly increased risk of injury. Compared to those bowlers with an average of 123-188 deliveries per week, bowlers with an average of fewer than 123 deliveries per week (RR = 1.4, 95% CI 1.0 to 2.0) or more than 188 deliveries per week (RR= 1.4, 95% CI 0.9 to 1.6) may also be at an increased risk of injury. There appears to be a dual fast bowling workload threshold beyond which the risk of injury increases and maintaining a workload that is too low or infrequent is an equally significant risk factor for injury as maintaining a high bowling workload. Further study is required to determine the reason why players who bowl infrequently suffer more injuries.

Injuries in Australian cricket at first class level 1995/1996 to 2000/2001.

OBJECTIVE: To describe and analyse injuries and illness occurring in Australian cricket at first class level. METHODS: Injuries occurring to the state and national teams were surveyed prospectively between the seasons 1998/1999 and 2000/2001, and the three preceding seasons were surveyed retrospectively. The definition of an injury was detailed and generally required the player to miss playing time in a major match. RESULTS: Average injury match incidence in the seasons studied prospectively varied from a low of 19.0 injuries per 10 000 player hours in first class domestic matches to a high of 38.5 injuries per 10 000 player hours in one day internationals. The average seasonal incidence was 19.2 injuries per squad (25 players) per season (20 matches). Injury prevalence (the percentage of players missing through injury at any given time) was 14% for pace bowlers, 4% for spin bowlers, 4% for batsmen, and 2% for wicket keepers. The most common injuries were hamstring strains, side strains, groin injuries, wrist and hand injuries, and lumbar soft tissue injuries. Bowlers who had bowled more than 20 match overs in the week leading up to a match had an increased risk of sustaining a bowling injury (risk ratio 1.91, 95% confidence interval (CI) 1.28 to 2.85). A further risk for bowling injury is bowling second in a match-that is, batting first (risk ratio 1.62, 95% CI 1.04 to 2.50). A risk factor for injury in fielding is colliding with the boundary fence. CONCLUSIONS: Further study is required to determine ways to minimise the risk of injury in fast bowlers. Cricket grounds should mark a boundary line on the playing field to prevent players colliding with fences in the field.

Exact moment of a gastrocnemius muscle strain captured on video.

A left gastrocnemius strain was sustained by an elite cricket batsman while he was taking off to run. The exact moment of injury, captured by a camera in the middle stump, appears to correspond to the sudden appearance of a deficit in the gastrocnemius muscle, seen through the player's trousers. The strain occurred when the entire body weight was on the left foot with the centre of mass well in front of the leg. The injury probably occurred close to the time when the gastrocnemius complex was moving from an eccentric to an isometric phase.

Cricket fast bowling performance and technique and the influence of selected physical factors during an 8-over spell.

The aims of this study were to determine the influence of an 8-over spell on cricket fast bowling technique and performance (speed and accuracy), and to establish the relationship of selected physical capacities with technique and performance during an 8-over spell. Fourteen first-grade fast bowlers with a mean age of 23 years participated in the study. Physical capacities assessed were abdominal strength, trunk stability, selected girth and skinfold measures. During the delivery stride, bowlers were filmed from an overhead and lateral perspective (50 Hz) to obtain two-dimensional data for transverse plane shoulder alignment and sagittal plane knee joint angle respectively. Ball speed was measured by a radar gun and accuracy by the impact point of each delivery on a zoned scoring target at the batter's stumps. Shoulder counter-rotation did not change significantly between overs 2 and 8 for all bowlers, but was significantly related to a more front-on shoulder orientation at back foot impact. When the front-on fast bowlers (n = 5) were isolated for analysis, shoulder counter-rotation increased significantly between overs 2 and 8. Ball speed remained constant while accuracy showed some non-significant variation during the spell. Shoulder counter-rotation was significantly related to accuracy scores during the second half of the 8-over spell. Chest girth and composition and body composition were significantly related to ball release speed at various times during the spell.