Asymmetrical abdominal muscle morphometry is present in injury free adolescent cricket pace bowlers: A prospective observational study.

Objectives: This study aimed to determine if abdominal muscle thickness, activation and symmetry are associated with prospective in-season injury among adolescent cricket pace bowlers.
Design: A quantitative, prospective, observational study design was used.
Setting: Data was collected at an indoor venue at a secondary school.
Participants: 28 injury-free, male, adolescent pace bowlers between the ages of 13 and 18 participated.
Main Outcome Measures: Muscle thickness of the transversus abdominis (TA), internal oblique (IO) and external oblique (EO) muscles were measured at rest and during an abdominal drawing-in maneuver (ADIM) i.e. activation, using ultrasound imaging. Incidence of injury was monitored monthly during the cricket season.
Results: Thickness of the non-dominant IO at rest was greater than the dominant side for pace bowlers who remained injury free during the cricket season (p = 0.01, effect size (ES) = 0.65). This was, however not the case for bowlers who sustained injuries (p = 0.47; ES = 0.24). TA percentage change during ADIM (activation) on the dominant side was less in bowlers who sustained non-contact injuries compared to those who remained injury free (p = 0.03; ES = 1.17).
Conclusions: Asymmetry in IO thickness may play a protective role against injury, whilst poor TA activation on the dominant side may pose a risk to injury.
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