Generally, an external fixator is mounted quite securely to the bone, and can withstand mild contact, any positioning of the body, and oftentimes even weightbearing immediately after surgery. In fact, it is often more comfortable to pick up the leg by grabbing the fixator, rather than holding the leg itself.he fixator is composed or one or more metal bars and rings, which in turn connect to a child via metal pins and wires. By gradually manipulating the fixator on the outside, we can carefully control the position of the bones and joints on the inside.
Habitat and Distribution. Pin this Image. Green sea urchins used to live in cold waters of the sub Polar Regions. They live in Northern cooler part of the Pacific and Atlantic Ocean. Some also live in the Arctic too. The sea animal can be found in rocky sea beds. They often live in the low depth tidal zones.
The red sea urchin (Mesocentrotus franciscanus) is a sea urchin found in the Pacific Ocean from Alaska to Baja California.It lives in shallow waters from the low-tide line to 90 m (300 ft) deep, and is typically found on rocky shores sheltered from extreme wave action. sea urchin's spherical body is completely covered by sharp spines that can grow up to 8 cm (3.1 in). These spines grow on a hard shell called the test, which encloses the animal. The oldest ones have been measured to be around 19 cm (7.5 in) in diameter.