The healthcare capabilities of Additive Manufacturing (3D Printing) are expanding both in material properties and design possibilities. These advances can now offer engineers and physicians a way to build sensors into the hollow cavities and voids of these parts. Combining hardware housing and sensor design leverages AM flexibility and customizability with a convenient way of sensoring wearable medical devices. Devices which are worn or used throughout a physical therapy rehabilitative period or as improvement to quality of life need to monitor and record their interaction with the wearer in order to maximize their performance and justify expenditure of resources to insurance providers. Many force measuring devices which interact with the human body extremities require wearer-specific geometry to function adequately so can be designed using a 3D scan of the appendage. The final device can be fabricated with AM techniques but still require sensors to be fitted afterwards externally. Medical sensing devices do not currently have a methodology to customize and embed force sensors for wearer-specifications, like orthotics for example. Increasing emphasis on evidence-based medicine for healthcare providers require more thorough real-time monitoring of a patient. In this research, we present a novel solution to this challenge so for the first time ever we can build the force sensor inside the device body and still customize it to the wearer and their needs. The core sensing element is injected after the part has been built and cleaned. Data is presented on sensor performance and device design.