Trial reportThe Journal of physiology1999
Effect of a 17 day spaceflight on contractile properties of human soleus muscle fibres.
Trial report in The Journal of physiology, 1999. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 74 papers, 2 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
74 citing papers in PubMed, 2 syntheses or guidelines pooled it, 267 citations in OpenAlex.
- Effects of Spaceflight on Musculoskeletal Health: A Systematic Review and Meta-analysis, Considerations for Interplanetary Travel.Sports medicine (Auckland, N.Z.) · 2021Pooled it
- Re-examination of 1- vs. 3-Sets of Resistance Exercise for Pre-spaceflight Muscle Conditioning: A Systematic Review and Meta-Analysis.Frontiers in physiology · 2019Pooled it
- A Resistive Soft Robotic Exosuit for Dynamic Body Loading in Hypogravity.Advanced science (Weinheim, Baden-Wurttemberg, Germany) · 2025Trial
- Whole body vibration training during allogeneic hematopoietic cell transplantation-the effects on patients' physical capacity.Annals of hematology · 2020Trial
- Effect of chronic unloading and rehabilitation on human Achilles tendon properties: a velocity-encoded phase-contrast MRI study.Journal of applied physiology (Bethesda, Md. : 1985) · 2008Trial
- Single muscle fiber adaptations to resistance training in old (>80 yr) men: evidence for limited skeletal muscle plasticity.American journal of physiology. Regulatory, integrative and comparative physiology · 2008Trial
- The temporal responses of protein synthesis, gene expression and cell signalling in human quadriceps muscle and patellar tendon to disuse.The Journal of physiology · 2007Trial
- Effects of 17-day spaceflight on knee extensor muscle function and size.European journal of applied physiology · 2005Trial
- Microgravity-induced changes in skeletal muscle and possible countermeasures: What we can learn from bed rest and human space studies.Experimental physiology · 2026Review
- Isometric training at longer muscle-tendon complex lengths: A potential countermeasure to impaired neuro-muscle-tendon function during space travel.Experimental physiology · 2026Review
- Type-specific and hibernation-associated skeletal muscle remodeling of the back muscle in Syrian hamsters.The journal of physiological sciences : JPS · 2026Article
- Skeletal muscle adaptation to microgravity: how altered mechanical cues drive catabolic signaling.EMBO reports · 2026Review
- Molecular signaling effects of electrical stimulation of the soleus muscle during 6 days of dry immersion.Sports medicine and health science · 2026Article
- Neuromuscular Electrical Stimulation to Combat Muscle Atrophy During Spaceflight: A Narrative Review of Mechanisms and Potential Applications.Life (Basel, Switzerland) · 2026Review
- The Structural Adaptations That Mediate Mechanical Load-Induced Changes in Muscle Mass.Advances in experimental medicine and biology · 2025Review
- Muscle atrophy in polytraumatized patients - a longitudinal observational pilot study.Frontiers in physiology · 2025Article
- Spaceflight increases sarcoplasmic reticulum CaNPJ microgravity · 2024Article
- Spaceflight on the ISS changed the skeletal muscle proteome of two astronauts.NPJ microgravity · 2024Article
- Nitrosative Stress in Astronaut Skeletal Muscle in Spaceflight.Antioxidants (Basel, Switzerland) · 2024Article
- A novel computational framework for the estimation of internal musculoskeletal loading and muscle adaptation in hypogravity.Frontiers in physiology · 2024Article
14 more citing papers are in PubMed but not listed here.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
11 authors at 3 institutions in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
1. Soleus biopsies were obtained from four male astronauts 45 days before and within 2 h after a 17 day spaceflight. 2. For all astronauts, single chemically skinned post-flight fibres expressing only type I myosin heavy chain (MHC) developed less average peak Ca2+ activated force (Po) during fixed-end contractions (0.78 +/- 0. 02 vs. 0.99 +/- 0.03 mN) and shortened at a greater mean velocity during unloaded contractions (Vo) (0.83 +/- 0.02 vs. 0.64 +/- 0.02 fibre lengths s-1) than pre-flight type I fibres. 3. The flight-induced decline in absolute Po was attributed to reductions in fibre diameter and/or Po per fibre cross-sectional area. Fibres from the astronaut who experienced the greatest relative loss of peak force also displayed a reduction in Ca2+ sensitivity. 4. The elevated Vo of the post-flight slow type I fibres could not be explained by alterations in myosin heavy or light chain composition. One alternative possibility is that the elevated Vo resulted from an increased myofilament lattice spacing. This hypothesis was supported by electron micrographic analysis demonstrating a reduction in thin filament density post-flight. 5. Post-flight fibres shortened at 30 % higher velocities than pre-flight fibres at external loads associated with peak power output. This increase in shortening velocity either reduced (2 astronauts) or prevented (2 astronauts) a post-flight loss in fibre absolute peak power (microN (fibre length) s-1). 6. The changes in soleus fibre diameter and function following spaceflight were similar to those observed after 17 days of bed rest. Although in-flight exercise countermeasures probably reduced the effects of microgravity, the results support the idea that ground-based bed rest can serve as a model of human spaceflight. 7. In conclusion, 17 days of spaceflight decreased force and increased shortening velocity of single Ca2+-activated muscle cells expressing type I MHC. The increase in shortening velocity greatly reduced the impact that impaired force production had on absolute peak power.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.