The Courier carries the spears at the hip and uses an overhand throwing technique. The spears are tossed in the air and caught before being thrown overhand.
The Throwing Spear has very high item health relative to most other thrown melee weapons, and as such would degrade very slowly, even though you can only attack once with it and it becomes irretrievable once thrown.
When holstered, the Throwing Spears are placed at the hip, like grenades. In reality, this would be dangerous, as it could cut and/or stab the user's arm or head.
Bugs
Xbox 360 Occasionally, a Poisoned Throwing Spear is lootable off of a White Legs corpse. This spear cannot be stored and once dropped, cannot be picked back up.