Releasable bindings were developed to reduce the risk of lower leg injuries. However, the relationship between the incidence of specific alpine injury groups and the function and calibration of the release system has not been well understood. Over the 32 years between December 1972 and April 2004, the authors conducted a case control study at a northern Vermont ski area involving 17 967 injuries and 3617 uninjured controls. During that time, approximately 6.4 million skier visits were recorded at the area. Injured skiers were treated at clinic in the base lodge and their injuries diagnosed by the clinic staff. Data relating to the accident, the injury, and the equipment used were recorded. The release moments of equipment associated with lower extremity injuries and uninjured controls were measured using a commercially available test device. Case studies of 43 anterior cruciate ligament (ACL) sprains, 79 lower leg injuries, and 99 uninjured controls were conducted using data collected over seven years between December 1997 and April 2004. In terms of quantitative critical defects, 17 % of the control group, 14 % of the ACL group, and 39 % of the lower leg group exhibited release levels more than 30 % above recommended. When qualitative critical defects were considered, 27 % of the control group, 25 % of the ACL group, and 54 % of the lower leg group were found to exhibit one or more defects capable of having a significant effect on equipment function. The authors concluded that sprains, fractures, strains, and contusions of the lower leg among alpine skiers were associated with measurable or observable qualities of the release system. Serious sprains of the knee were not. A substantial reduction of injuries below the knee can be expected if potentially defective equipment can be identified and repaired, or replaced.