| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Institute for Biophysical & Clinical Research into Human Movement, Manchester Metropolitan University, Alsager, United Kingdom
2 Centre Medical Universitaire, University of Geneva, Geneva, Switzerland
* To whom correspondence should be addressed. E-mail: N.Reeves{at}mmu.ac.uk.
While microgravity exposure is known to cause deterioration of skeletal muscle performance, little is known regarding its effect on tendon structure and function. Hence, the aims of this study were to investigate the effects of simulated microgravity on the mechanical properties of human tendon and to assess the effectiveness of resistive countermeasures in preventing any detrimental effects. Eighteen males (aged 25-45 years) underwent 90 days bed rest; nine performed resistive exercise during this period (BREx group) and nine underwent bed rest only (BR group). Calf-raise and leg-press exercises were performed every third day using a gravity-independent flywheel device. Isometric plantarflexion contractions were performed using a custom-built dynamometer and ultrasound imaging was used to determine the tensile deformation of the gastrocnemius tendon during contraction. In the BR group,tendon stiffness estimated from the gradient of the tendon force-deformation relation decreased by 58% (pre: 124 ± 67 N.mm-1; post: 52 ± 28 N.mm-1; P < 0.01) and the tendon Young's modulus decreased by 57% post-intervention (P < 0.01). In the BREx group, tendon stiffness decreased by 37% (pre: 136 ± 66 N.mm-1; post: 86 ± 47 N.mm-1; P < 0.01) and the tendon Young's modulus decreased by 38% post-intervention (P < 0.01). The relative decline in tendon stiffness and Young's modulus was significantly (P < 0.01) greater in the BR group compared to the BREx group. Unloading decreased gastrocnemius tendon stiffness due to a change in tendon material properties and although the exercise countermeasures did attenuate these effects, they did not completely prevent them. It is suggested that the total loading volume was not sufficient to completely prevent alterations in tendon mechanical properties.
This article has been cited by other articles:
|
|
 |
|
  O. R. Seynnes, R. M. Erskine, C. N. Maganaris, S. Longo, E. M. Simoneau, J. F. Grosset, and M. V. Narici Training-induced changes in structural and mechanical properties of the patellar tendon are related to muscle hypertrophy but not to strength gains J Appl Physiol, August 1, 2009; 107(2): 523 - 530. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Andersson, P. Eliasson, and P. Aspenberg Tissue memory in healing tendons: short loading episodes stimulate healing J Appl Physiol, August 1, 2009; 107(2): 417 - 421. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. M. Heinemeier, J. L. Olesen, F. Haddad, P. Schjerling, K. M. Baldwin, and M. Kjaer Effect of unloading followed by reloading on expression of collagen and related growth factors in rat tendon and muscle J Appl Physiol, January 1, 2009; 106(1): 178 - 186. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. C. Carroll, J. M. Dickinson, J. M. Haus, G. A. Lee, C. J. Hollon, P. Aagaard, S. P. Magnusson, and T. A. Trappe Influence of aging on the in vivo properties of human patellar tendon J Appl Physiol, December 1, 2008; 105(6): 1907 - 1915. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. Christensen, E. Dyrberg, P. Aagaard, M. Kjaer, and H. Langberg Short-term immobilization and recovery affect skeletal muscle but not collagen tissue turnover in humans J Appl Physiol, December 1, 2008; 105(6): 1845 - 1851. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. Shin, T. Finni, S. Ahn, J. A. Hodgson, H.-D. Lee, V. R. Edgerton, and S. Sinha Effect of chronic unloading and rehabilitation on human Achilles tendon properties: a velocity-encoded phase-contrast MRI study J Appl Physiol, October 1, 2008; 105(4): 1179 - 1186. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. Christensen, E. Dyrberg, P. Aagaard, S. Enehjelm, M. Krogsgaard, M. Kjaer, and H. Langberg Effects of long-term immobilization and recovery on human triceps surae and collagen turnover in the Achilles tendon in patients with healing ankle fracture J Appl Physiol, August 1, 2008; 105(2): 420 - 426. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. P. Magnusson, M. V. Narici, C. N. Maganaris, and M. Kjaer Human tendon behaviour and adaptation, in vivo J. Physiol., January 1, 2008; 586(1): 71 - 81. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. D. de Boer, C. N. Maganaris, O. R. Seynnes, M. J. Rennie, and M. V. Narici Time course of muscular, neural and tendinous adaptations to 23 day unilateral lower-limb suspension in young men J. Physiol., September 15, 2007; 583(3): 1079 - 1091. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. Eliasson, A. Fahlgren, B. Pasternak, and P. Aspenberg Unloaded rat Achilles tendons continue to grow, but lose viscoelasticity J Appl Physiol, August 1, 2007; 103(2): 459 - 463. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Z. Paxton and K. Baar Tendon mechanics: the argument heats up J Appl Physiol, August 1, 2007; 103(2): 423 - 424. [Full Text] [PDF]
|
|
|
|
 |
|
 A. Arampatzis, K. Karamanidis, and K. Albracht Adaptational responses of the human Achilles tendon by modulation of the applied cyclic strain magnitude J. Exp. Biol., August 1, 2007; 210(15): 2743 - 2753. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. M. Arruda, S. Calve, R. G. Dennis, K. Mundy, and K. Baar Regional variation of tibialis anterior tendon mechanics is lost following denervation J Appl Physiol, October 1, 2006; 101(4): 1113 - 1117. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. C. Clark, B. Fernhall, and L. L. Ploutz-Snyder Adaptations in human neuromuscular function following prolonged unweighting: I. Skeletal muscle contractile properties and applied ischemia efficacy J Appl Physiol, July 1, 2006; 101(1): 256 - 263. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Bojsen-Moller, K. K. Kalliokoski, M. Seppanen, M. Kjaer, and S. P. Magnusson Low-intensity tensile loading increases intratendinous glucose uptake in the Achilles tendon J Appl Physiol, July 1, 2006; 101(1): 196 - 201. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H.-D. Lee, T. Finni, J. A. Hodgson, A. M. Lai, V. R. Edgerton, and S. Sinha Soleus aponeurosis strain distribution following chronic unloading in humans: an in vivo MR phase-contrast study J Appl Physiol, June 1, 2006; 100(6): 2004 - 2011. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. L. Onambele, M. V. Narici, and C. N. Maganaris Calf muscle-tendon properties and postural balance in old age J Appl Physiol, June 1, 2006; 100(6): 2048 - 2056. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 N. D. Reeves, M. V. Narici, and C. N. Maganaris Myotendinous plasticity to ageing and resistance exercise in humans Exp Physiol, May 1, 2006; 91(3): 483 - 498. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |
