Rittweger et al. 2010 measured tibial bone at five timepoints during 56-day bed rest but published numeric values at only three — none within the bed-rest phase — leaving the loss time course unquantified in the text

space-medicineaerospace-physiologybone-densitybed-rest-analogstudy-designpqct

The Berlin BedRest (BBR) study — 56 days of strict horizontal bed rest in 20 healthy men, Rittweger et al. 2010, Böcker et al. 2026's reference 22 — is invoked for the temporal shape of bed-rest bone loss, a question distinct from the compartment split its almost-exclusively-cortical finding settles. Read directly, the paper's Methods show that it did take repeated pQCT measurements within the bed-rest phase, not merely a baseline-versus-end pair: "Bone measurements were obtained once during baseline data collection (BDC), on days 2, 17, 31, 45, and 55 of the bed rest phase" (BR.2, BR.17, BR.31, BR.45, BR.55), alongside six post-reambulation timepoints. The design therefore holds, in principle, the data needed to characterize the intra-bed-rest time course — ruling out the possibility, hedged in the open question, that the study measured only at the start and end.

The published paper does not report those five measurements as numbers. Its summary table of total BMC (Table 5) gives only three timepoints per site — "BMC values at baseline (BDC), on the 14th day of recovery, and at 12-month follow-up (R+360), given as means and their SD in brackets" — skipping every intra-bed-rest measurement. The within-bed-rest trajectory appears only graphically, in Fig. 2 (distal tibia epiphysis and 66% diaphysis, difference from baseline over time) and Fig. 4 (cortical and trabecular area/BMC across the five bed-rest timepoints); neither yields numeric values to a text extraction.

[unverified-quant — needs primary]: no fitted curve, rate comparison, or statistical test of linear-versus-front-loaded accrual exists in the paper's text or tables for the bed-rest phase, and none is recorded here. This is the limit of what the primary settles for Böcker's front-loading hypothesis and the linearity-vs-deceleration question. The direction the paper's prose does support — away from front-loading — is in claim-rittweger-2010-bed-rest-cortical-loss-prose-points-away-from-front-loading. See question-verify-rittweger-2010-bed-rest-cortical-loss-time-course.