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. 2018 Jan 25;9:27.
doi: 10.3389/fphys.2018.00027. eCollection 2018.

The Effect of Bed Rest and Hypoxic Environment on Postural Balance and Trunk Automatic (Re)Actions in Young Healthy Males

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Free PMC article

The Effect of Bed Rest and Hypoxic Environment on Postural Balance and Trunk Automatic (Re)Actions in Young Healthy Males

Nejc Šarabon et al. Front Physiol. .
Free PMC article

Abstract

Prolonged inactivity, such as bed rest induces several detrimental changes within a short timeframe. Impaired postural balance and responses of trunk muscles to (un)expected perturbations were both shown to be impaired after bed rest. Certain populations (e.g., astronauts) are exposed to hypoxic environment in addition to inactivity, similar to bed rest. While the isolated negative effects of hypoxia on postural balance have been observed before, no study to date has examined the combined effects of hypoxia and bed rest on postural balance or trunk muscle responses. In this study, we examined the effects of 21-day exposure to three conditions: (i) bed rest in hypoxic environment (HBR), (ii) bed rest in normoxic environment (NBR), and (iii) ambulatory hypoxic environment (HAMB). Fourteen healthy male subjects crossed over between conditions in a randomized order, with a 4-month break between conditions to ensure full recovery. Most body sway parameters indicated a similar deterioration of postural balance following both HBR and NBR. Similarly, both anticipatory and reactive responses of the trunk muscles (m. erector spinae and m. multifidus) were impaired after HBR and NBR to a similar degree and mostly unchanged after HAMB. Certain body sway parameters were impaired after HAMB, confirming that hypoxia alone can undermine postural balance. On the other hand, some trunk responses were improved after HAMB. In conclusion, the results of our study confirmed previous findings on negative effects of bed rest, but showed little or no additional effect of hypoxia during bed rest. Physical activity during bed rest is encouraged to preserve neuromuscular functions of the trunk. While the HBR condition in our study resembled conditions during space missions, our results could be relevant to other populations, such as patients with pulmonary diseases exposed to bed rest.

Keywords: balance; bed rest; function; hypoxia; inactivity; trunk.

Figures

Figure 1
Figure 1
Differences in anticipatory postural adjustments' latencies, maximal amplitudes and rate of EMG rise before and after interventions (means and 95% CI).
Figure 2
Figure 2
Differences in postural reflex responses' latencies, maximal amplitudes and rate of EMG rise before and after interventions (means and 95% CI).
Figure 3
Figure 3
Differences in antero-posterior (A-P) and medio-lateral (M-L) body sway velocities in three different stances, before and after interventions (means and 95% CI).

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References

    1. Bodkin D. K., Escalera P., Bocam K. J. (2006). A human Lunar surface base and infrastructure solution. Am. Inst. Aeronaut. Austronaut. 7336, 1–17. 10.2514/6.2006-7336 - DOI
    1. Debevec T., Bali T. C., Simpson E. J., Macdonald I. A., Eiken O., Mekjavic I. B. (2014). Separate and combined effects of 21-day bed rest and hypoxic confinement on body composition. Eur. J. Appl. Physiol. 114, 2411–2425. 10.1007/s00421-014-2963-1 - DOI - PubMed
    1. Degache F., Larghi G., Faiss R., Deriaz O., Millet G. (2012). Hypobaric versus normobaric hypoxia: same effects on postural stability? High Alt. Med. Biol. 13, 40–45. 10.1089/ham.2011.1042 - DOI - PubMed
    1. Dousset E., Steinberg J. G., Balon N., Jammes Y. (2001a). Effects of acute hypoxemia on force and surface EMG during sustained handgrip. Muscle Nerve 24, 364–371. 10.1002/1097-4598(200103)24:3<364::AID-MUS1007>3.0.CO;2-B - DOI - PubMed
    1. Dousset E., Decherchi P., Grelot L., Jammes Y. (2001b). Effects of chronic hypoxemia on the afferent nerve activities from skeletal muscle. Am. J. Respir. Crit. Care Med. 164(8 Pt 1), 1476–1480. 10.1164/ajrccm.164.8.2010135 - DOI - PubMed

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