Complex sentence: MODAM's musculature is atrophied (at least proportionally) while her head has been enlarged, thus she is physically dependent on the exoskeleton provided by her hover-chair for physical support and movement.
Split into simpler sentences: MODAM's musculature is atrophied (at least proportionally) while her head has been enlarged. Thus she is physically dependent on the exoskeleton provided by her hover-chair for physical support and movement.