Lumbar muscle atrophy and increased relative intramuscular lipid concentration are not mitigated by daily artificial gravity after 60-day head-down tilt bed rest

This study presents novel insights into the morphological adaptations occurring in lumbar spine after 60-day head-down bed rest and potential role of artificial gravity (AG) to mitigate them. Results demonstrated no protective effect AG protocols used this study. In atrophied paraspinal muscles, ratio lipids versus intramuscular water increased postural which could impair muscle function during upright standing. These findings have relevance for future space explorations.