We constantly plan movements that appear to us as having a singular purpose. We can accomplish these abstract goals using feedback from physiological organs that do not directly encode the same metric as defined by those goals. In my work, I examined the dynamics of the muscle-tendon complex during various tasks to infer how biological sensors like muscle proprioceptors may be involved in accomplishing such goals. To better study this non-invasively, I tested the use of solid gel in ultrasound imaging to demonstrate that I can obtain images comparable in quality to more traditional liquid ultrasound gel to measure various muscle structures while ameliorating some pitfalls associated with liquid gels such as non-reusability and the loss of contact between the probe and skin. I also looked at the tibialis anterior muscle during steady-state walking and found that its lengthening velocity relates closely to the whole-body metabolic cost of transport, implicating it as a potential contributing indirect sensor in the overall estimate of walking economy. I then focused on the medial gastrocnemius muscle during a countermovement jump in response to a simulated hypogravity exposure and saw that though there weren’t many appreciable differences in the muscle behavior, subjects still felt a perceptible aftereffect. These results suggest that many other different sensors are likely being integrated into the holistic sense of gravity and that there may be error-based feedback related to expected muscle behavior that is not apparent from basic muscle length feedback. Studies into physiological sensors and their potential functions beyond their afferent encoding help give a fuller appreciation of how we perceive the world around us.