Proprioception is considered one of the human senses and it is described as the sense of orientation of a persons limbs in space, which is different from sensing external reality. Proprioception is different from the sense of balance, which is a function traced to the fluids found in the inner ear. This is called equilibrioception. Proprioception is what police officers look at when a person is pulled over under suspicion of being drunk. If there is no proprioception, humans will have to always look at their feet in order to make sure that they will stay upright when walking.
Proprioception, unlike equilibrioception, cannot be linked to any specific organ. It is related to the whole nervous system. The inputs for it come from sensory receptors, which are different from tactile receptors. This means it is related to the nerves located inside the body, and not the nerves located on the bodys surface. Just like a motor activity, proprioceptive abilities can also be trained.
In order to fully understand how proprioception works, one has to find out how people will function without it. For example, without proprioception, a man wont be able to drive with their eyes fixed on the road. He will have to always look at the position of his arms and legs while he works the pedals and the steering wheel. Touch typing would also be impossible without proprioception.
When trying to learn a new motor skill, it will also involve training the proprioceptive senses that will be used when performing such a skill.