I agree proprioception is important in fiction, but I think of senses as being more immediate outputs of our sensors: touch, pain, temperature, sight, hearing, smell, taste, balance, etc. Proprioception seems like a more downstream integrated signal inferred from sight, balance, touch, and hearing.
Not really. You actually have a unique set of sensory neurons that tell you the spacial orientation of your body by measuring muscle/ligament stretch:
https://en.m.wikipedia.org/wiki/Proprioception
Edit: yes your general "body sense" is intergrated over multiple senses, including sight, touch, inner ear, ... but my point is that proprioception is an independent signal in that mix.
