Partial weight bearing does not prevent musculoskeletal losses associated with disuse.

Purpose: The purpose of this study was to investigate whether partial weight-bearing activity, at either one-sixth or one-third of body mass, blunts the deleterious effects of simulated microgravity (0G) after 21 d on muscle mass and quantitative/qualitative measures of bone.

Methods: Using a novel, previously validated partial weight-bearing suspension device, mice were subjected to 16% (G/3, i.e.

Discordant recovery of bone mass and mechanical properties during prolonged recovery from disuse.

Profound bone loss at weight bearing sites is a primary effect of long-duration spaceflight. Moreover, a significant increase in estimated fracture risk remains even 1 year after returning to Earth; hence, it is important to define how quickly bone integrity can recover following prolonged disuse. This study characterized the loss and recovery dynamics of bone following a period of rodent hindlimb unloading in three anatomic sites.