Development of a Mechanical-Loading Countermeasure Skinsuit to Mitigate Post-Spaceflight Sensorimotor Dysfunction

Exposure to altered gravity is an ongoing challenge for sensorimotor function and, accordingly, countermeasures are required to preserve a range of functional outcomes. Here, we describe the sensorimotor countermeasure skinsuit (SMCS) concept and preliminary characterization of the baseline suit component. The SMCS is proposed for sessional intravehicular use while in microgravity and comprises a full-body garment providing mild axial loading from the shoulders to the feet and mild resting compression over the torso, arms, and legs. Mechanical properties of the suit fabric and integrated loading elements are to provide tailored limb and torso �weighting� via resistance to certain movements and static and dynamic cutaneous pressure stimuli. In a first step of development, the baseline suit component was custom-made for one participant and preliminary characterization performed. The baseline suit was able to meet or exceed the 0.1 g axial loading (AL) targets at the shoulders (~0.2 g AL) and feet (~0.15 g AL). Range of motion (ROM) of the arms was promising despite inclusion of arm coverage, with shoulder flexion and abduction limited by <20% (versus without the suit). The dominant influence of the suit on restricting ROM was for hip flexion (limited by ~35%) and integrated hip and back flexion (poor reach during the sit-and-reach test). A range of improvements to the baseline suit are planned and integration of the additional loading elements for targeted weighting of limb movement are next steps.