2007, Piran, Slovenia
2007, Piran, Slovenia 2007, Piran, Slovenia
Environmental Ergonomics XII Igor B. Mekjavic, Stelios N. Kounalakis & Nigel A.S. Taylor (Eds.), © BIOMED, Ljubljana 2007 DISCUSSION Skeletal muscle atrophy is one of the primary problems associated with microgravity and simulated weightlessness models. Our findings confirm previous observation of a greater susceptibility to atrophy of the postural muscles, such as the GM, and least of the non-antigravity muscles, such as the BB. Contractile changes were described for contraction time (Tc) and the peak amplitude (Dm) of the twitch muscle contraction response. Tc changes were significantly reduced in ES and increased in GM muscles. This observation is somewhat surprising in that both the ES and GM are extensor, i.e. antigravity, muscles. Whereas the decrease in Tc seems consistent with a greater expression of fast MHC isoforms with disuse (Trappe et al., 2004), an increase Tc in the GM is difficult to explain, particularly because previous bed rest studies have found an increase in fast MHC isoforms expression (Trappe et al., 2004). Dm changes were more predictable as we observed increased Dm in all leg and lower back muscles. Statistical significance was confirmed in GM, VM and BF muscles. As the subjects were allowed to move their arms freely no affect was observed in BB muscle, neither in Dm nor in Tc. Dm confirmed that subjects with stiffer muscles in the baseline had bigger Dm increase after bed-rest (P < 0.05 in BB, BF and VM). This observation may be explained by, 1) an increase in intramuscular connective tissue, known to occur with atrophy and, 2) an increase in antagonist muscle co-activation, frequently found in atrophy and sarcopenia (Reeves et al. 2006). It seems plausible that an increase in muscle stiffness may be needed to compensate for the loss in tendon stiffness known to occur with prolonged bed rest (Reeves et al. 2005), since this may preserve the stiffness of the muscle-tendon complex as a whole. REFERENCES Adams G.R., Caiozzo V.J. & Baldwin K.M. (2003). Skeletal muscle unweighting: spaceflight and ground-based models. J Appl Physiol 95, 2185-2201. Caiozzo V.J., Haddad F., Baker M.J., Herrick R.E., Prietto N. & Baldwin K.M. (1996). Microgravity-induced transformations of myosin isoforms and contractile properties of skeletal muscle. Journal of Applied Physiology 81, 123-132. Caiozzo V.J., Baker M.J., Herrick R.E., Tao M. & Baldwin K.M. (1994) Effect of spaceflight on skeletal muscle: mechanical properties and myosin isoform content of a slow muscle. J Appl Physiol 76, 1764-1773. Dahmane R., Valenčič V., Knez N. & Eržen I. (2000). Evaluation of the ability to make non-invasive estimation of muscle contractile properties on the basis of the muscle belly response. Med Biol Eng Comput 83, 51-55. Dahmane R.G., Djordjevič S., Šimunič B. & Valenčič V. (2005). Spatial fiber type distribution in normal human muscle histochemical and tensiomyographical evaluation. J Biomech, 38(12), 2451-2459. Delagi E.F., Perotto A., Iazzetti J., & Morrison D. (1975). Anatomic guide for the electromyographer: the limbs. Charles C. Thomas, Springfield, Illinois, USA. 54
Gravitational Physiology Edgerton V.R., Zhou M.Y., Ohira Y., Klitgaard H., Jiang B., Bell G., Harri, B., Saltin B., Gollnick P.D., Roy R.R., Day M.K. & Greenisen M. (1995). Human fiber size and enzymatic properties after 5 and 11 days of spaceflight. Journal of Applied Physiology 78, 1733-1739. Evetovich T.K., Housh T.J., Stout J.R., Johnson G.O., Smith D.B. & Ebersole K.T. (1997). Mechanomyographic responses to concentric isokinetic muscle contractions, Europ J Appl Occup Physiol 75(2), 166-169. Fitts R.H., Riley D.R. & Widrick J.J. (2000). Microgravity and skeletal muscle. J. Appl. Physiol. 89, 823–839. Grigoryeva L.S. & Kozlovskaya I.B. (1987). Effect of weightlessness and hypokinesis on velocity and strength properties of human muscles. Kosmicheskaya Biologiya I Aviakosmicheskaya Meditsina 21, 27-30. Koryak Y. (1995). Contractile properties of the human triceps surae muscle during simulated weightlessness. Eur J Appl Physiol 70, 344–350. LeBlanc A., Rowe R., Schneider V., Evans H. & Hedrick T. (1995). Regional muscle loss after duration spaceflight. Aviat Space Environ Med 66, 1151-1154. Ohira Y., Yoshinaga T., Ohara M., Nonaka I., Yoshioka T., Yamashita-Goto K., Shenkman B.S., Kozlovskaya I.B., Roy R.R. & Edgerton V.R. (1999). Myonuclear domain and myosin phenotype in human soleus after bed rest with or without loading. J Appl Physiol 87, 1776–1785. Pišot R., Valenčič V., Šimunič B. (2002). Influence of biomechanical properties of particular skeletal muscles on child motor development. Ann Ser hist nat 12, 99- 106. Reeves N.J., Maganaris C.N., Ferretti G., Narici M.V. (2002). Influence of simulated microgravity on human skeletal muscle architecture and function. J Gravit Physiol 9(1), 153-154. Reeves N.D., Maganaris C.N., Ferretti G., Narici M.V. (1998). Influence of 90-day simulated microgravity on human tendon mechanical properties and the effect of resistive countermeasures. J Appl Physiol. 98(6), 2278-86. Reeves N.D., Narici M.V., Maganaris C.N. (2002). Myotendinous plasticity to ageing and resistance exercise in humans. Exp Physiol, 91(3), 483-98. Toursel T., Stevens L., Granzier H. & Mounier Y. (2002). Passive tension of rat skeletal muscle fibres: effects of unloading conditions. J Appl Physiol 92(4), 1465- 1472. Trappe S., Trappe T., Gallagher P., Harber M., Alkner B., Tesch P. (2004). Human single muscle fibre function with 84 day bed-rest and resistance exercise. J Physiol 557(2), 501-513. Valenčič V. (1990). Direct measurement of the skeletal muscle tonus. Advances in External Control of Human Extremities, Nauka, Beograd. Widrick J.J., Knuth S.T., Norenberg K.M., Romatowski J.G., Bain J.L., Riley D.A., Karhanek M., Trappe S.W., Trappe T.A., Costill D.L. & Fitts R.H. (1999). Effect of a 17 day spaceflight on contractile properties of human soleus muscle fibres. J Physiol 516, 915–930. Zhou M.Y., Klitgaard H., Saltin B., Roy R.R., Edgerton V.R. & Gollnick P.D. (1995). Myosin heavy chain isoforms of human muscle after short-term spaceflight. J Appl Physiol 78, 1740-1744. 55
- Page 3 and 4: ENVIRONMENTAL ERGONOMICS XII Procee
- Page 5 and 6: International Conferences on Enviro
- Page 7 and 8: TABLE OF CONTENTS Table of contents
- Page 9 and 10: Table of contents ALTITUDE ATTENUAT
- Page 11 and 12: Table of contents TOWARDS PREVENTIO
- Page 13 and 14: Table of contents RATE AFFECT EXERC
- Page 15 and 16: Table of contents Uroš Dobnikar, S
- Page 17 and 18: Table of contents TO A HOT ENVIRONM
- Page 19 and 20: Table of contents Andreas D. Flouri
- Page 21 and 22: Table of contents PHYSICAL FITNESS
- Page 23 and 24: Table of contents ESTIMATION OF THE
- Page 25 and 26: Herman Potocnic Lecture the advanta
- Page 27 and 28: Invited presentation Gravitational
- Page 29 and 30: Gravitational Physiology SKELETAL M
- Page 31 and 32: Lf (mm) 50.0 40.0 30.0 20.0 10.0 Fa
- Page 33 and 34: Gravitational Physiology maximum is
- Page 35 and 36: Gravitational Physiology THERMOREGU
- Page 37 and 38: Gravitational Physiology THE EXERCI
- Page 39 and 40: Gravitational Physiology Since exer
- Page 41 and 42: Gravitational Physiology During the
- Page 43 and 44: Gravitational Physiology CARDIOVASC
- Page 45 and 46: as observed at rest after LBNP was
- Page 47 and 48: Gravitational Physiology THERMOREGU
- Page 49 and 50: Gravitational Physiology THE EFFECT
- Page 51 and 52: Gravitational Physiology Fortney SM
- Page 53: Gravitational Physiology Contractil
- Page 57 and 58: Diving Physiology A library of imag
- Page 59 and 60: Diving Physiology Information recal
- Page 61 and 62: Diving Physiology RESULTS Figure 1
- Page 63 and 64: Diving Physiology sensitivity is no
- Page 65 and 66: Diving Physiology Physiological Mea
- Page 67 and 68: Diving Physiology same sequence. Th
- Page 69 and 70: Diving Physiology HYPERVENTILATION
- Page 71 and 72: Diving Physiology software. Individ
- Page 73 and 74: Diving Physiology REFERENCES IMCA.
- Page 75 and 76: Diving Physiology recorded (MIE Med
- Page 77 and 78: Diving Physiology DISCUSSION The ma
- Page 79 and 80: Altitude Physiology vastus laterali
- Page 81 and 82: Altitude Physiology IS INTERMITTENT
- Page 83 and 84: Altitude Physiology Table 2: Lactat
- Page 85 and 86: Altitude Physiology CARBOHYDRATE IN
- Page 87 and 88: Altitude Physiology Figure 1: Mean
- Page 89 and 90: Altitude Physiology HYPOXIA INDUCED
- Page 91 and 92: Altitude Physiology Figure 1. Mean
- Page 93 and 94: Altitude Physiology ANALYSIS OF MUS
- Page 95 and 96: SOL MG TA BF VM Altitude Physiology
- Page 97 and 98: Altitude Physiology LOAD CARRIAGE I
- Page 99 and 100: Table 2: Differential ratings of pe
- Page 101 and 102: Altitude Physiology EFFECTS OF INTE
- Page 103 and 104: Cerebral deoxy-Hb (delta, µM) Cere
Gravitational Physiology<br />
Edgerton V.R., Zhou M.Y., Ohira Y., Klitgaard H., Jiang B., Bell G., Harri, B., Saltin<br />
B., Gollnick P.D., Roy R.R., Day M.K. & Greenisen M. (1995). Human fiber size<br />
and enzymatic properties after 5 and 11 days of spaceflight. Journal of Applied<br />
Physiology 78, 1733-1739.<br />
Evetovich T.K., Housh T.J., Stout J.R., Johnson G.O., Smith D.B. & Ebersole K.T.<br />
(1997). Mechanomyographic responses to concentric isokinetic muscle<br />
contractions, Europ J Appl Occup Physiol 75(2), 166-169.<br />
Fitts R.H., Riley D.R. & Widrick J.J. (2000). Microgravity and skeletal muscle. J.<br />
Appl. Physiol. 89, 823–839.<br />
Grigoryeva L.S. & Kozlovskaya I.B. (1987). Effect of weightlessness and hypokinesis<br />
on velocity and strength properties of human muscles. Kosmicheskaya Biologiya<br />
I Aviakosmicheskaya Meditsina 21, 27-30.<br />
Koryak Y. (1995). Contractile properties of the human triceps surae muscle during<br />
simulated weightlessness. Eur J Appl Physiol 70, 344–350.<br />
LeBlanc A., Rowe R., Schneider V., Evans H. & Hedrick T. (1995). Regional muscle<br />
loss after duration spaceflight. Aviat Space Environ Med 66, 1151-1154.<br />
Ohira Y., Yoshinaga T., Ohara M., Nonaka I., Yoshioka T., Yamashita-Goto K.,<br />
Shenkman B.S., Kozlovskaya I.B., Roy R.R. & Edgerton V.R. (1999).<br />
Myonuclear domain and myosin phenotype in human soleus after bed rest with or<br />
without loading. J Appl Physiol 87, 1776–1785.<br />
Pišot R., Valenčič V., Šimunič B. (2002). Influence of biomechanical properties of<br />
particular skeletal muscles on child motor development. Ann Ser hist nat 12, 99-<br />
106.<br />
Reeves N.J., Maganaris C.N., Ferretti G., Narici M.V. (2002). Influence of simulated<br />
microgravity on human skeletal muscle architecture and function. J Gravit<br />
Physiol 9(1), 153-154.<br />
Reeves N.D., Maganaris C.N., Ferretti G., Narici M.V. (1998). Influence of 90-day<br />
simulated microgravity on human tendon mechanical properties and the effect of<br />
resistive countermeasures. J Appl Physiol. 98(6), 2278-86.<br />
Reeves N.D., Narici M.V., Maganaris C.N. (2002). Myotendinous plasticity to ageing<br />
and resistance exercise in humans. Exp Physiol, 91(3), 483-98.<br />
Toursel T., Stevens L., Granzier H. & Mounier Y. (2002). Passive tension of rat<br />
skeletal muscle fibres: effects of unloading conditions. J Appl Physiol 92(4), 1465-<br />
1472.<br />
Trappe S., Trappe T., Gallagher P., Harber M., Alkner B., Tesch P. (2004). Human<br />
single muscle fibre function with 84 day bed-rest and resistance exercise. J<br />
Physiol 557(2), 501-513.<br />
Valenčič V. (1990). Direct measurement of the skeletal muscle tonus. Advances in<br />
External Control of Human Extremities, Nauka, Beograd.<br />
Widrick J.J., Knuth S.T., Norenberg K.M., Romatowski J.G., Bain J.L., Riley D.A.,<br />
Karhanek M., Trappe S.W., Trappe T.A., Costill D.L. & Fitts R.H. (1999). Effect<br />
of a 17 day spaceflight on contractile properties of human soleus muscle fibres. J<br />
Physiol 516, 915–930.<br />
Zhou M.Y., Klitgaard H., Saltin B., Roy R.R., Edgerton V.R. & Gollnick P.D. (1995).<br />
Myosin heavy chain isoforms of human muscle after short-term spaceflight. J<br />
Appl Physiol 78, 1740-1744.<br />
55
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