Exploring short-term microgravity as a therapeutic intervention for spinal degeneration and disc space narrowing: A narrative review

Degenerative disc disease (DDD) and chronic low back pain are prevalent in the general population and athletic populations exposed to high spinal loading. Environments with simulated microgravity, such as dry immersion, water immersion, and parabolic flight, may mimic the spinal unloading experienced in space and have shown potential in enhancing disc hydration, reducing axial stress, and promoting recovery. In this narrative review, we evaluate the therapeutic potential of short-term simulated microgravity exposure for spinal rehabilitation and athletic recovery, highlighting mechanisms and clinical applications. A comprehensive literature search was conducted in PubMed, EMBASE, Web of Science, and EBSCO, following the PICOS framework. Studies involving simulated or real microgravity and reporting outcomes related to disc hydration, extracellular matrix remodeling, biomechanical properties, or molecular signaling were included. A total of 9 original research articles met the inclusion criteria. Short-term microgravity exposure increases intervertebral disc hydration and disc height while stimulating the synthesis of proteoglycans in the matrix. Mechanistically, these effects are mediated by a reduction in axial loading, osmotic water influx, and the activation of pathways such as the transforming growth factor-β (TGF-β)/Smad3 pathway. Clinically, simulated microgravity may serve as a noninvasive modality for recovery in athletes with spinal overload, offering alternatives to conventional therapies via parabolic flight, aquatic therapy, or dry immersion. Simulated microgravity represents a novel, noninvasive modality that may aid in spinal rehabilitation by enhancing disc hydration and reducing mechanical stress. While early evidence is promising, further clinical trials are needed to validate the safety, efficacy, and integration of simulated microgravity into multidisciplinary sports medicine protocols.