Injuries to the lower extremities of belted car occupants in frontal collisions are frequent and can be impairing. Crash parameters and vehicle attributes increase or decrease the risk of injury. Real-world accident data collected within the UK under the Co-operative Crash Injury Study (CCIS) has been used to examine these effects. AIS 2+ injuries are most common below the knees of both drivers and passengers. Intrusion of the footwell increases the risk of leg injury to a greater extent than crash severity under the conditions experienced in the accident data. Intrusion is shown not to be a proxy variable for delta-V. The pedals increase the risk of leg injury by 54% when there is 20 cm of footwell intrusion.The study indicates the need for an improved understanding of the injury mechanisms involved and the mechanism through which intrusion increases leg injury. There is also the need to examine the effect of the brake pedal on leg injury as pedal intrusion may be greater than the surrounding footwell.