Injury risk associated with ground hardness in junior cricket

Objectives: To establish if there is an association between ground hardness and injury risk in junior cricket.

Design: Nested case-series of players who played matches on specific grounds with objective ground hardness measures, within a prospective cohort study of junior community club cricket players.

Methods: Monitoring of injuries and playing exposure occurred during 434 matches over the 2007/2008 playing season. Objective assessment of the hardness of 38 grounds was undertaken using a Clegg hammer at 13 sites on 19 different junior cricket grounds on the match eve across the season. Hardness readings were classified from unacceptably low (<30 g) to unacceptably high (>120 g) and two independent raters assessed the likelihood of each injury being related to ground hardness. Injuries sustained on tested grounds were related to the ground hardness measures.

Results: Overall, 31 match injuries were reported; 6.5% were rated as likely to be related to ground hardness, 16.1% as possibly related and 74.2% as unlikely to be related and 3.2% unknown. The two injuries likely to be related to ground hardness were sustained whilst diving to catch a ball resulting, in a graze/laceration from contact with hard ground. Overall, 31/38 (82%) ground assessments were rated as having 'unacceptably high' hardness and all others as 'high/normal' hardness. Only one injury occurred on an objectively tested ground.

Conclusions: It remains unclear if ground hardness is a contributing factor to the most common injury mechanism of being struck by the ball, and needs to be confirmed in future larger-scale studies.