Disk degeneration and fast bowling in cricket: an intervention study.

PURPOSE: The purpose of this study was to identify the relationship between the incidence of lumber disk degeneration and bowling technique after 3 yr of educational intervention.
METHODS: Two groups of cricketers from the Western Australian fast-bowling development squads acted as subjects in this longitudinal study. Group 1 comprised 24 fast bowlers, of mean age 13.4 yr at the commencement of the study. They attended at least three of the four yearly testing sessions between 1997 and 2000. A further 17 of mean age (in 1998) of 13.2 yr attended a minimum of two of three yearly testing sessions between 1998 and 2000, and comprised group 2. Players were filmed laterally and from above by two video cameras during each testing session. Specific technique variables that previously had been linked with an increased incidence of lumbar disk abnormalities were measured from the videos. Magnetic resonance imaging (MRI) scans of the lumbar disks of each player were also recorded at approximately the same time. A yearly half-day clinic and six small group coaching sessions spread over the season were held to assist the bowlers develop techniques that had been linked with a reduction in back injuries.
RESULTS: Data showed that small group coaching significantly reduced the level of shoulder alignment counter-rotation in young fast bowlers. The incidence and progression of lumbar disk degeneration were also significantly reduced in parallel with this decreased shoulder counter-rotation.
CONCLUSION: Technique assessment and modifications through an educational process aimed at reducing mechanical features that have been linked to back injury decreased the incidence and/or progression of lumbar spine disk degeneration.