At the transition point to the ulna shaft there is a rough area (tuberositas ulnae) for attachment of the musculus brachialis, which bends the lower arm in the elbow joint. The three-sided surface of the ulna is separated by the laterally pointing interosseous edge (margo interosseus), an edge pointing to the front (margo anterior), and a rear edge (margo posterior).
A broken arm is a common injury. Counting all fractures, about one in every 20 involve the upper arm bone (humerus). Children are more likely to break the lower arm bones (radius and ulna). Falling on an outstretched hand or being in a car crash or some other type of accident is usually the cause of a broken arm. Most people know right away if their arm broke, because there may be a snap or a loud cracking sound. The broken arm may appear deformed and be swollen, bruised and bleeding. A person with a broken arm usually has:
A control arm is an important part of the suspension system of a car. There are several different types that are used to do things, control the steering of a car and to keep the wheels from bouncing too much. This system is also part of what drives the car as it works to counteract the torque from the engine. Suspension systems have an upper control arm working in concert with the lower control arm. Having these control arms is what makes it possible to steer the vehicle when power is being applied to the wheels.