James Waldie

The effect of the gravity loading countermeasure skinsuit upon movement and strength.

Abstract Carvil, PA, Attias, J, Evetts, SN, Waldie, JM, and Green, DA. The effect of the gravity loading countermeasure skinsuit upon movement and strength. J Strength Cond Res 31(1): 154–161, 2017—Effective countermeasures against musculoskeletal deconditioning induced by microgravity and disuse are required. A simple alternative to provision of artificial gravity by centrifugation is compressive axial loading. The Russian “Pingvin” suit was the first wearable suit to apply this concept using bungee cords tethered around the shoulders and feet. However, poor loading characteristics and severe thermal and movement discomfort were reported. The gravity loading countermeasure skinsuit (GLCS) uses a bidirectional weave to generate staged axial loading from shoulders to feet, better mimicking how Earths gravity induces progressive loading head to foot. The Mk III GLCSs loading was evaluated and tolerability assessed during maximal joint motion, ambulation, and selected strength exercises. Eight subjects (5 male and 3 female; 28 ± 3 years; 179 ± 0.1 cm and 74.8 ± 2.9 kg), having given written informed consent, had an Mk III GLCS individually tailored. Axial loading imparted, body height, joint range of motion (ROM), ambulation, and strength tests (12 repetition maximum) were performed in the GLCS and gym attire, with subjective (rating of perceived exertion, thermal comfort, movement discomfort and body control) ratings recorded throughout. Gravity loading countermeasure skinsuit provided significant axial loading when standing but significantly reduced knee (−13°), spinal (−28°) and shoulder flexion/extension ROM (−34°/−13°), in addition to Sit and Reach (−12.8 cm). No thermal issues were reported but there was an increase in subjective discomfort. Gravity loading countermeasure skinsuit did not significantly impede strength exercise, with the exception of shoulder press. The GLCS (Mk III) demonstrates potential as a countermeasure by providing tolerable, static axial loading. Furthermore, it may serve as an elasticlike strength exercise adjunct, which may have utility as a rehabilitation modality after further design refinement.

Modeling and Design of a BioSuit Donning System

Mechanical counterpressure (MCP) spacesuits use form-fitting elastic garments to produce pressure against the skin. MCP suits offer significant mobility, energy expenditure, and safety advantages over stiff, immobile, and bulky gas-pressurized suits currently used for extravehicular activity. However, one of the major challenges associated with MCP suits is the difficulty of putting the suit on and taking it off, or donning and doffing. This research develops a network of gas-pressurized tubes integrated to the outside of an elastic glove to aid in donning. When pressurized, the tubes expand, pulling open the MCP garment. The stretched material and enlarged opening allow the person to don the glove easily. The system was designed using a mathematical model of the expansion properties of the tubes and resistance of the glove material. A prototype consisting of an MCP glove at a fraction of the current spacesuit pressure and the gas-pressurized tubing system was developed to achieve a proof-of-concept design. The use of gas-pressurized tubing to solve the MCP donning problem has been demonstrated at fractional suit pressures and shows promise to be extrapolated to a full pressure MCP glove.