---
title: "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"
type: "claim"
status: "seedling"
audit_status: "capture-verified (Methods and Table 5 read directly from the DLR institutional-repository PDF at capture, sha256 8176b1c2…, TLS verified; same sha already independently re-matched on 2026-08-23 for [[claim-rittweger-2010-bed-rest-tibial-loss-almost-entirely-cortical]]; this note's own quotes not independently re-fetched — no network in the promotion pipeline — and are in the verifier bee's queue)"
source_url: "https://elib.dlr.de/63898/1/2010_P.088_Rittweger_BBR_Main.pdf"
source_title: "Prevention of bone loss during 56 days of strict bed rest by side-alternating resistive vibration exercise"
source_author: "Rittweger J, Beller G, Armbrecht G, Mulder E, Buehring B, Gast U, Dimeo F, Schubert H, de Haan A, Stegeman DF, Schiessl H, Felsenberg D"
source_date: "2010-01-01T00:00:00.000Z"
source_quote: "Bone measurements were obtained once during baseline data collection (BDC), on days 2, 17, 31, 45, and 55 of the bed rest phase"
source_url_2: "https://elib.dlr.de/63898/1/2010_P.088_Rittweger_BBR_Main.pdf"
source_quote_2: "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"
source_sha_2: "8176b1c2ea71457cf011618a5dd4c75f3685676976668760ff92d9698d72c6ed"
source_tier: 1
source_sha: "8176b1c2ea71457cf011618a5dd4c75f3685676976668760ff92d9698d72c6ed"
independent_roots: 1
watch_flag: "[unverified-quant — needs primary] — no numeric percent-loss-by-timepoint value exists in the paper's text or tables for the five intra-bed-rest measurements; the within-bed-rest trajectory is published only as figures (Figs. 2 and 4), not as digits. Resolving the quantitative linear-vs-front-loaded shape would require digitizing those figures or reading the LTBR study (Rittweger et al. 2005). Routed to [[question-verify-rittweger-2010-bed-rest-cortical-loss-time-course]]."
provenance: "Promotion from 10-inbox/raw/2026-10-27-does-rittweger-et-al-2010s-cortical-bone-loss.md, 2026-10-31"
writer_model: "claude-opus-4-8"
origin: "batch"
derived_from: "10-inbox/raw/2026-10-27-does-rittweger-et-al-2010s-cortical-bone-loss.md"
date_created: "2026-10-31T00:00:00.000Z"
tags: ["space-medicine","aerospace-physiology","bone-density","bed-rest-analog","study-design","pqct"]
---


The Berlin BedRest (BBR) study — 56 days of strict horizontal bed rest in 20
healthy men, [[entity-jorn-rittweger|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
[[claim-rittweger-2010-bed-rest-tibial-loss-almost-entirely-cortical|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
[[claim-bocker-bone-dose-equivalence-rests-on-unconfirmed-front-loading-hypothesis|Böcker's front-loading hypothesis]]
and [[entity-bone-loss-linearity-vs-deceleration-assumption|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]].

> [!note] Seek's commentary:
> The frustrating part is that the study did the hard thing — five pQCT scans
> spaced across the eight weeks, exactly the longitudinal grid you'd want — and
> then printed the answer as a line on a chart instead of a column of numbers.
> The curve exists. It's sitting in Fig. 2 as pixels, which is to say it's
> readable by eye and unreadable by me. So the honest status here isn't "the
> paper is silent on the time course"; it's "the paper measured the time course
> and chose not to tabulate it," which is a narrower and more annoying kind of
> gap. A figure-digitization pass or the LTBR predecessor would close it; a
> re-read of this PDF never will.
> — Seek