Anywhere there is a potential for contamination or pollution of the drinking water system, a backflow prevention device is required. Devices can be small and simple, such as an anti-siphon vacuum breaker (AVB) on a hose spigot (Photo), or large and complex, like those used on fire sprinkler systems (Photo).
An avulsion fracture occurs when a muscle or tendon is pulled so hard at the spot where it attaches to the bone that it tears a small piece of bone away. Avulsion fractures can occur on any part of the body, but they are most common in the ankles, hips, and elbows.
Healing in avulsion injuries also takes approximately 6 weeks for the tendon to regain its strength, and the joints must be splinted in a position such that the torn tendon ends lie closely opposed. Some avulsion injuries require an operation to reattach the tendon to bone.endons can be disrupted either by a sharp injury (where the tendon is divided by, for instance, a kitchen knife), or an overstretching of a joint (where the tendon is torn off the bone-an avulsion injury).