Janine Gray

Dissociation between back pain and bone stress reaction as measured by CT scan in young cricket fast bowlers

Background: Bone stress reaction is prevalent among cricket fast bowlers. Few studies have addressed the sensitivity and specificity of imaging for diagnosis, and follow up assessment has been poorly investigated. Objective: To determine whether there was an association between back pain and bone stress reaction as measured by computed tomography (CT) scan in young cricket fast bowlers. Methods: Ten young cricket fast bowlers were included in the study. Nine bowlers presented to a physiotherapy practice with low back pain and were later diagnosed with lumbar stress fractures, while one was an experienced bowler with no pain. All players had a CT scan after presenting to the physiotherapy practice. Pain was assessed according to a subjective scale (0–10) where 10 represented the player’s subjective, maximum pain score. Recovery and rehabilitation of all players was monitored until they returned to full participation. Results: There was no consistency in the relationship between pain and CT scan results. For example, one subject had evidence of un-united stress fractures after 15 months of rest but had experienced moderate pain for only 2 weeks after the onset of symptoms, in contrast to another subject who had intermittent pain for 11 months even though CT scan showed multiple stress fractures ranging from partially healed to fully healed status at 3 months. Conclusion: There is dissociation between back pain and bone stress reaction as measured by CT scan. Therefore, CT scan does not provide objective evidence for ongoing management or decision concerning return to sport in cricket fast bowlers.

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.

Event-related potentials, reaction time, and response selection of skilled and less-skilled cricket batsmen.

The differences in P300 latency, P300 amplitude, response selection, and reaction time between skilled and less-skilled cricket batsmen have been investigated. Eight skilled and ten less-skilled right-handed batsmen each viewed 100 in-swing, 100 out-swing, and 40 slower deliveries displayed in random sequence from projected video footage whilst their responses and electro-encephalograms were recorded. Logistic regression was used to derive a discriminative function for the P300 data. This was done to determine whether the skilled batsmen differed from the less-skilled batsmen on the basis of pooled P300 amplitude and latency data. All the batsmen were correctly characterised as being skilled or less-skilled. Logistic regression equations with reaction time and correctness of response data indicated that behavioural data do not correctly classify skilled performance. It is suggested that skilled cricket batsmen have a superior perceptual decision-making ability compared with less-skilled cricket batsmen, as measured by P300 latency and amplitude. This appears to be the first study showing a link between skill and cerebral cortical activity during a perceptual cricket batting task and it could pave the way for future studies on mental processing in cricket batsmen.

Symmetry, not asymmetry, of abdominal muscle morphology is associated with low back pain in cricket fast bowlers

OBJECTIVES Although abdominal muscle morphology is symmetrical in the general population, asymmetry has been identified in rotation sports. This asymmetry includes greater thickness of obliquus internus abdominis (OI) on the non-dominant side in cricketers. Cricket fast bowlers commonly experience low back pain (LBP) related to bowling action, and this depends on trunk muscle control. This study aimed to compare abdominal muscle thickness between fast bowlers with and without LBP. DESIGN Cross sectional descriptive study. METHODS Twenty-five adolescent provincial league specialist fast bowlers (16 with and 9 without LBP) participated. Static ultrasound images (US) of OI, and obliquus externus (OE) and transversus abdominis (TrA) were captured on the dominant and non-dominant side in supine. RESULTS Total combined thickness of OE, OI and TrA muscles was greater on the non-dominant than dominant side (p=0.02) for fast bowlers without LBP, but symmetrical for those with pain. Total thickness was less on the non-dominant side for bowlers with pain than those without (p=0.03). When individual muscles were compared, only the thickness of OI was less in bowlers with LBP than those without (p=0.02). All abdominal muscles were thicker on the non-dominant side in controls (p<0.001) but symmetrical in LBP. CONCLUSIONS Asymmetry of abdominal muscle thickness in fast bowlers is explained by the asymmetrical biomechanics of fast bowling. Lesser OI muscle thickness in fast bowlers with LBP suggests modified trunk control in the transverse/frontal plane and may underpin the incidence of lumbar pathology. The implications for rehabilitation following LBP in fast bowlers require further investigation.

UPPER BODY MUSCLE STRENGTH AND BATTING PERFORMANCE IN CRICKET BATSMEN

Taliep, MS, Prim, SK, and Gray, J. Upper body muscle strength and batting performance in cricket batsmen. J Strength Cond Res 24(12): 3484-3487, 2010-The aim of this study was to determine if upper body muscle strength (as measured by the 1 repetition maximum bench press) was associated with cricket batting performance. Cricket batting performance was defined by the maximum hitting distance during a batting task and batting average and strike rate during 1-Day and Twenty/20 (T/20) matches. Eighteen, provincial level, elite cricket batsmen participated in the study. Upper body muscle strength was found to be positively correlated with maximum hitting distance (p = 0.0052). There were no significant correlations between upper body strength, batting average, and strike rate for both the 1-Day and T/20 matches. The results of this study have implications for coaches choosing a particular batting line-up. Batsmen who have stronger upper bodies could be favored to bat when a match situation requires them to hit powerful strokes resulting in boundaries. However, coaches cannot use upper body strength as a predictor of overall batting performance in 1-Day or T/20 matches.

Extrinsic and intrinsic factors associated with non-contact injury in adult pace bowlers: a systematic review protocol

Review question/objective Review question: which extrinsic and intrinsic factors are associated with non‐contact injury in adult cricket pace bowlers? Review objective: the objective of this review is to determine the extrinsic and intrinsic factors associated with non‐contact injury in adult pace bowlers. Background Cricket is generally considered to be a sport of low injury risk1 compared to other sports.2 In cricket, the pace bowler strives towards the adoption of a bowling technique with a relatively low injury threat that will, at the same time, allow for a fast (>120km/hr) and accurate delivery to the opposing batsman. However, of all the various roles of the cricket player, the pace bowler has the highest risk of injury, especially for low back and lower limb (lower quarter) injury.3,4 The reason for this high risk of injury is due to the inherent, high‐load biomechanical nature of the pace bowling action.3‐5 The high prevalence of injury amongst pace bowlers3,4 highlights the great need for research into factors associated with injury. Both extrinsic and intrinsic factors work in combination to predispose the bowler to injury. Extrinsic or environment‐related factors include bowling workload (the numbers of overs a bowler bowls), player position (first, second or third change) and time of play (morning or afternoon). A high bowling workload has been linked with a higher risk of injury in pace bowlers. Foster et al.5 found in an observational study that bowling too many overs in a single spell or bowling too many spells may increase the pace bowlers risk of sustaining a low back injury. In another observational study, Dennis et al.6 found that an exceptionally high bowling workload as well as an uncommonly low bowling workload is associated with injury risk. The major extrinsic factors for bowling injury identified by Orchard et al.1 are a high number of match overs bowled in the previous week, number of days of play and bowling second (batting first) in a match. Extrinsic factors are known to make the bowler more susceptible to injury, especially in the presence of intrinsic factors. Intrinsic, or person‐related, factors include muscle strength, flexibility, balance and biomechanics.7‐11 Intrinsic, strength‐related factors, such as shoulder depression, horizontal flexion strength for the preferred limb and quadriceps power in the non‐preferred limb are also significantly related to back injuries in fast bowlers.5 Both upper limb and lower limb‐related intrinsic factors are known to be associated with injury. A prospective study by Dennis et al.12 aimed to identify the risk factors for injury in adolescent cricket fast bowlers. Their findings concluded that bowlers with a hip internal rotation range of motion of ≤30° on the leg ipsilateral to the bowling arm were at a significantly reduced risk of injury compared with bowlers with >40° of rotation. Moreover, bowlers with ankle dorsiflexion lunge of 12.1‐14.0 cm on the leg contralateral to the bowling arm were at a significantly increased risk of injury compared to bowlers with a lunge of >14 cm. Reduced hamstring flexibility was also associated with lumbar disc abnormalities.13 Bowling‐related biomechanical risk factors for injury have been established such as trunk rotation of the shoulders by to a more side‐on position during the delivery stride.5 Portus et al.14 also reported that shoulder counter‐rotation was significantly higher in bowlers who reported lumbar spine stress fractures, while the non‐trunk injured group displayed a more flexed knee at front foot contact and ball release. In addition to the above kinematic risk factors, there are high ground reaction forces associated with the power phase ‐ between the front foot placement and ball release components of the pace bowling action.15‐17 A combination of kinematic bowling related issues as described above and high ground reaction forces may predispose the bowler to injury. Morton et al.18 conducted a systematic review on pace bowlers between the ages of 13.7 and 22.5 years on risk factors and successful interventions for cricket‐related low back pain. Young cricketers between the ages of 13 and 18 years are different to adults in terms of their physiology which impacts on their predisposition to injury and phases of healing.19,20 Young cricketers may differ from an adult population in that young pace bowlers who sustain injuries during their bowling career may have given up on the sport by the time they approach adulthood, and the composition of the adult pace bowler population group is therefore affected by natural selection which may cause this group to differ from the original population. Caution is thus advised when generalizing findings from this young population group to adult pace bowlers which emphasizes the need for studies amongst adult pace bowlers. Furthermore, the review by Morton et al.18 included articles that specifically investigated factors associated with low back pain. However, due to the interconnectedness between the spine and the lower limbs, kinematic variables affecting the spine will also affect the load placed on the lower limbs21,22 with subsequent risk of injury.23 The interdependent mechanical interactions in a linked segment system such as the system of motion of the low back can be caused by movement coordination patterns in other body segments.24 The systematic review by Morton et al.18 only included intrinsic factors while the proposed review will also look at extrinsic factors. Therefore, the primary objective of this review is to determine extrinsic and intrinsic factors associated with non‐contact injury in adult pace bowlers.

The mental wellbeing of current and retired professional cricketers: an observational prospective cohort study

ABSTRACT Objective: Scientific knowledge about symptoms of common mental disorders in professional cricket is non-existent. Consequently, the aims of the study were to determine the prevalence and the 6 months incidence of symptoms of common mental disorders (CMD: distress, anxiety/depression, sleep disturbance, adverse alcohol use) among current and former professional cricketers and to explore the association of potential stressors (significant injury, surgery, adverse life events, career dissatisfaction) and CMD. Methods: An observational prospective cohort study with a follow-up period of 6 months was conducted among current and former professional cricketers from South Africa. Using validated questionnaires to assess symptoms of common mental disorders as well as several stressors, an electronic questionnaire was set up and distributed by the South African Cricketers Association (SACA). Results: A total of 116 participants enrolled at baseline (overall response rate of 33%) and 76 of those participants completed the 6 month follow-up (follow up rate of 66%). The prevalence of symptoms of CMD in current professional cricketers was 38% for distress, 38% for sleep disturbance, 37% for anxiety/depression and 26% for adverse alcohol use. Among former professional cricketers, baseline prevalence as was 26% for distress, 24% for anxiety/depression, 21% for sleep disturbance and 22% for adverse alcohol use. Career dissatisfaction led to an increased risk of distress, anxiety/depression and sleep disturbance in current professional cricketers. Surgeries and adverse life events led to an increase in reported symptoms of distress and anxiety/depression in current professional cricketers. Conclusions: It was concluded that symptoms of CMD are prevalent in both current and former professional cricketers and the association with surgery, adverse life events and cricket career dissatisfaction may provide some insight into possible mechanisms.

Musculoskeletal predictors of non-contact injury in cricketers – Few and far between? A longitudinal cohort study

OBJECTIVE To determine the musculoskeletal risk factors for injury amongst professional, domestic cricket players. DESIGN Longitudinal cohort study. SETTING Medical suites associated with the respective cricket franchises. PARTICIPANTS Professional, domestic cricket players (n = 97). MAIN OUTCOME MEASURES A pre-participatory musculoskeletal screening battery consisting of 21 tests including flexibility, neural tension, stability, strength, balance and pain provocation tests at the start of the cricket season. Non-contact, low back and lower limb (lower quarter) injuries were monitored throughout the season. Binary logistic regression and receiver operating curves were used to determine predictive value of each test. RESULTS During the course of the cricket season, 38 of the 97 (39.2%) cricketers sustained a non-contact low back and/or lower limb injury. Increased hip internal rotation ROM on the dominant side (OR = 1.065; p = 0.036), no symptoms on active slump dominant side (OR = 0.289; p = 0.014), decreased combined elevation (OR = 0.934; p = 0.029), increased shoulder internal rotation ROM on the non-dominant side (OR = 1.022; p = 0.035) and increased GIRD (glenohumeral internal rotation deficit) (OR = 1.026; p = 0.042) predicted in-season non-contact lower quarter injuries. Although statistically significant, none of these variables were strong predictors of injury as shown by the logistic regression models (accuracy in classification rate: 59.8-62.9%), the area under the curve (AUC) of the receiver operating characteristic (ROC) curves (AUC≤0.652) and the cut-off scores which revealed high sensitivity (68.4-86.8%), but low specificity (25.4-54.2%). CONCLUSION Although only a few of the many tests included in the battery showed predictive validity, the value of screening procedures should not be underestimated due to other benefits such as building patient rapport, identification of pre-existing injuries, establishing clinical and functional baselines upon which individualised management programmes can be based.