Effects of a microgravity SkinSuit on lumbar geometry and kinematics

Abstract

Purpose Astronauts returning from long ISS missions have demonstrated an increased incidence of lumbar disc herniation accompanied by biomechanical and morphological changes associated with spine elongation. This research describes a ground-based study of the effects of an axial compression countermeasure Mk VI SkinSuit designed to reload the spine and reduce these changes before return to terrestrial gravity. Methods Twenty healthy male volunteers aged 21–36 without back pain participated. Each lay overnight on a Hyper Buoyancy Flotation (HBF) bed for 12 h on two occasions 6 weeks apart. On the second occasion participants donned a Mk VI SkinSuit designed to axially load the spine at 0.2 Gz during the last 4 h of flotation. Immediately after each exposure, participants received recumbent MRI and flexion–extension quantitative fluoroscopy scans of their lumbar spines, measuring differences between spine geometry and intervertebral kinematics with and without the SkinSuit. This was followed by the same procedure whilst weight bearing. Paired comparisons were performed for all measurements. Results Following Mk VI SkinSuit use, participants evidenced more flexion RoM at L3–4 (p = 0.01) and L4–5 (p = 0.003), more translation at L3–4 (p = 0.02), lower dynamic disc height at L5–S1 (p = 0.002), lower lumbar spine length (p = 0.01) and greater lordosis (p = 0.0001) than without the Mk VI SkinSuit. Disc cross-sectional area and volume were not significantly affected. Conclusion The MkVI SkinSuit restores lumbar mobility and lordosis following 4 h of wearing during hyper buoyancy flotation in a healthy control population and may be an effective countermeasure for post space flight lumbar disc herniation.

Lunar and mars gravity induce similar changes in spinal motor control as microgravity

“…The sensitivity of spinal stiffness to gravitational changes and a potential link to vertebral kinematics ( Breen et al, 2023 ) suggests that its evaluation is warranted during spaceflight, but also in response to ARED use, and candidate spinal deconditioning countermeasures such as axial-loading provided by SkinSuit, as such loading has been suggested to promote spinal control on Earth ( Rathinam et al, 2013 ). Recently, the Mk VI SkinSuit ( Stabler et al, 2017 ), devised to provide ≈0.2gz axial loading ameliorated spinal elongation and back pain by ≈ 50% induced by 8-h HBF by ≈ 50% ( Green et al, 2023 ), as well as restoring lumbar mobility and lordosis following 4 h HBF ( Breen et al, 2023 ).…”

“…However, the functional value of such changes remains to be determined ( Plehuna et al, 2022 ). Yet in another ground-based model of µg termed hyper-buoyancy flotation (HBF) developed to model stature elongation and back pain ( Green et al, 2023 ) is also associated with modulation in lumbar kinematics ( Breen et al, 2023 ). Recent parabolic flight studies have also showed a rapid increase in lumbar (L3) spine stiffness, defined as resistance to deformation of the spinal system ( Panjabi, 1992b ; Panjabi, 1992a ; Hodges et al, 2013 ; Needle et al, 2014 ).…”