Intrinsic variables associated with low back pain and lumbar spine injury in fast bowlers in cricket: a systematic review.

BACKGROUND: Lumbar spine injuries in fast bowlers account for the greatest missed playing time in cricket. A range of extrinsic and intrinsic variables are hypothesised to be associated with low back pain and lumbar spine injury in fast bowlers, and an improved understanding of intrinsic variables is necessary as these may alter load tolerance and injury risk associated with fast bowling. This review critically evaluated studies reporting intrinsic variables associated with low back pain and lumbar spine injury in fast bowlers and identified areas for future investigation. METHODS: OVID Medline, EMBASE, SPORTDiscus, CINAHL, Web of Science and SCOPUS databases were last searched on 3 June 2022 to identify studies investigating intrinsic variables associated with low back pain and lumbar spine injury in cricket fast bowlers. Terms relevant to cricket fast bowling, and intrinsic variables associated with lumbar spine injury and low back pain in fast bowlers were searched. 1,503 abstracts were screened, and 118 full-text articles were appraised to determine whether they met inclusion criteria. Two authors independently screened search results and assessed risk of bias using a modified version of the Quality in Prognostic Studies tool. RESULTS: Twenty-five studies met the inclusion criteria. Overall, no included studies demonstrated a low risk of bias, two studies were identified as moderate risk, and twenty-three studies were identified as high risk. Conflicting results were reported amongst studies investigating associations of fast bowling kinematics and kinetics, trunk and lumbar anatomical features, anthropometric traits, age, and neuromuscular characteristics with low back pain and lumbar spine injury. CONCLUSION: Inconsistencies in results may be related to differences in study design, injury definitions, participant characteristics, measurement parameters, and statistical analyses. Low back pain and lumbar spine injury occurrence in fast bowlers remain high, and this may be due to an absence of low bias studies that have informed recommendations for their prevention. Future research should employ clearly defined injury outcomes, analyse continuous datasets, utilise models that better represent lumbar kinematics and kinetics during fast bowling, and better quantify previous injury, lumbar anatomical features and lumbar maturation. TRIAL REGISTRATION: Open Science Framework https://doi.org/10.17605/OSF.IO/ERKZ2 .

MRI Bone Marrow Edema Signal Intensity: A Reliable and Valid Measure of Lumbar Bone Stress Injury in Elite Junior Fast Bowlers.

STUDY DESIGN: Comparative reliability and prospective validity. OBJECTIVE: First, to evaluate the reliability of four methods of assessing magnetic resonance imaging (MRI) bone marrow edema (BMO) of the posterior vertebral arch of the lumbar vertebrae of elite junior fast bowlers. Second, to evaluate the validity of the most reliable method for the early detection of lumbar bone stress injury. SUMMARY OF BACKGROUND DATA: MRI has demonstrated utility in identifying BMO in lumbar vertebrae. Methods to grade the severity of BMO may provide valuable insight to inform clinical management, particularly in elite athletes where detection of early-stage bone stress may prevent progression to more severe and costly bone stress injury. METHODS: Sixty-five male elite junior fast bowlers had repeat MRI scans during a cricket season. A subset of 19 bowlers' images were reassessed by experienced musculoskeletal radiologists to determine intra- and inter-rater reliability. All images were aligned with independent medical records of lower back symptoms and diagnosed bone stress injuries to establish the relationship of BMO and lumbar bone stress injury. RESULTS: Clinical detection of abnormal BMO, whether the pars region of the vertebra was considered in its entirety or subdivided into regions, had fair-to-moderate inter-rater reliability, and fair-to-almost perfect intra-rater reliability. Measurement of BMO signal intensity using an imaging software tool had excellent intra-rater and inter-rater reliability (ICC = 0.848, 0.837). BMO signal intensity was positively associated with subsequent LBSI (P < 0.001), and differentiated between asymptomatic and symptomatic bowlers (P < 0.001). CONCLUSION: Measurement of BMO signal intensity using an imaging software tool proved a reliable and valid measure of the severity of lumbar bone stress injury in elite junior fast bowlers. LEVEL OF EVIDENCE: 2.

MRI bone marrow oedema precedes lumbar bone stress injury diagnosis in junior elite cricket fast bowlers.

OBJECTIVES: Lumbar bone stress injury ('bone stress injury') is common in junior fast bowlers. The repetitive loading of cricket fast bowling may cause bone marrow oedema (BMO), detectable on MRI, before the bowler suffers from symptomatic bone stress injury. We investigated the temporal relationship between BMO, bone stress injury, along with bowling workload correlates, in elite junior fast bowlers throughout a cricket season. METHODS: 65 junior fast bowlers were prospectively monitored for one 8-month cricket season. For research purposes, participants had up to six MRI scans at set times in the season; findings were withheld from them and their clinicians. Standard practices for bowling workload monitoring and injury diagnosis were followed. RESULTS: 15 (23%) participants developed bone stress injury during the study. All 15 of these participants had BMO detected on at least one of the preceding MRI scans, including the scan immediately prior to diagnosis. The risk of BMO progressing to bone stress injury during the season was greatest for participants with BMO present 2 weeks prior to the national championship tournament (period of high load) (RR=18.9, OR=44.8). Both bone stress injury and BMO were associated with bowling a higher percentage of days in training and having a shorter bowling break during the season. The number of balls bowled and acute-to-chronic workload were not associated with imaging abnormalities or injury. CONCLUSION: The presence of BMO on MRI in asymptomatic junior cricket fast bowlers confers a very high risk for bone stress injury. The risk may be managed by MRI screening and monitoring bowling frequency.

Comparison of the Physical and Technical Demands of Cricket Players During Training and Match-Play.

Vickery, W, Duffield, R, Crowther, R, Beakley, D, Blanch, P, and Dascombe, BJ. Comparison of the physical and technical demands of cricket players during training and match-play. J Strength Cond Res 32(3): 821-829, 2018-This study aimed to determine which training method (net-based sessions or center-wicket simulations) currently used in national level and U19 male players cricket provided a more physical and technical match-specific training response. The heart rate, rating of perceived exertion, and movement patterns of 42 male cricket players were measured across the various training and match formats. Video analysis was coded retrospectively to quantify technical loads based on the cricket skills performed. Magnitude-based inferences were based on the standardization of effect and presented with ±90% confidence intervals. Regardless of playing position, differences in physiological demands between training modes and match-play were unclear, with the exception of higher heart rates in fielders during traditional net sessions (mean heart rate: d = -2.7 [-4.7 to -0.7]; 75% of maximum heart rate: d = -1.7 [-3.2 to -0.2]). Typically, the movement demands of center-wicket simulations were similar or greater than match-play, which was most evident in the distance traveled at a high intensity within each playing position (batsmen: d = 6.4 [3.7-9.2]; medium-fast bowlers: d = 1.71 [0.1-3.3]; spin bowlers: d = 6.5 [0.01-13.0]; fielders: d = 0.8 [-0.2 to 1.7]). The technical demands of traditional net cricket training exceeded that of a typical match for each playing position. Specifically, fast bowlers delivered a greater number of balls during net-bowling compared with a match (d = -2.2 [-3.6 to 0.9]). In conclusion, center-wicket simulations more closely matched the physical demands of a One-Day match within batsmen and spin bowlers, whereas traditional cricket training often exceeded match-specific demands.