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.
Sea urchins mainly congregate in colder, offshore waters, but sometimes travel into shallower waters looking for food. The green sea urchin of New England is often found in tide pools and below the low-tide line. They also tend to shy away from light. Their tests grow to a size of three or four inches.