Effect of disuse on the ultrastructure of the achilles tendon in rats

Nakagawa, Yoku; Totsuka, Manabu; Sato, Tomoaki; Fukuda, Yoshiro; Hirota, Koichi

doi:10.1007/bf02386194

Cited by 83 publications

(54 citation statements)

References 13 publications

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“…Indeed, Vailas et al (1988) have indicated a decrease in the concentration of collagen and proteoglycans of the patellar tendon of the rat after HS. Moreover, Nakagawa et al (1989) have reported that HS induced a decrease in both surface area and diameter of collagen ®bres from the tendon of the rat soleus muscle. Both results would induce an increase in compliance of tendon structures.…”

Section: Discussionmentioning

confidence: 98%

Effects of chronic low frequency stimulation on contractile and elastic properties of hindlimb suspended rat soleus muscle

Canon

Goubel

Guezennec

1997

European Journal of Applied Physiology

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Chronic low frequency stimulation (10 Hz, 8 h x day[-1]) was used in this study to prevent the changes in the contractile and elastic properties of rat soleus muscles induced by 3 weeks of hindlimb suspension (HS). Results showed that electrostimulation was able to counteract in part the decrease in soleus muscle mass and tension output induced by unweighting. On the other hand, the increases in maximal shortening velocity and twitch speed following HS were not prevented by stimulation. Unweighting was responsible for an increase in series elastic compliance of soleus muscle. Chronic stimulation successfully counteracted this increase in series compliance probably by changing the properties of the tendon. The partial recovery of muscle mass and tension output as a result of stimulation enhanced the role of contractile activity in preventing muscle atrophy. Moreover, the inefficiency of the tonic activity imposed by stimulation in preventing the increase in twitch speed of soleus muscle during HS demonstrated the primacy of neuronal activity. Discrepant results concerning changes in contraction kinetics deduced from the twitch could have been due to the fact that such myograms also depend on the series compliance.

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Section: Discussionmentioning

confidence: 98%

Effects of chronic low frequency stimulation on contractile and elastic properties of hindlimb suspended rat soleus muscle

Canon

Goubel

Guezennec

1997

European Journal of Applied Physiology

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“…9 Karpakka et al 15 reported that activities of prolyl 4-hydroxylase and galactosylhydroxylysyl glucosyltransferase, which are used for estimating alterations in the rate of collagen biosynthesis under different experimental and clinical conditions, decreased after 3 weeks of immobilization. Nakagawa et al 19 showed that decreased thickness of collagen fibers at the Achilles tendon resulted from disuse. They concluded that this decrease of collagen fiber thickness leads to a decrease in tensile strength.…”

mentioning

confidence: 99%

“…They concluded that this decrease of collagen fiber thickness leads to a decrease in tensile strength. The biochemical studies by Karpakka et al 15 and Nakagawa et al 19 showed that there were changes in the tensile strength of series elastic components following disuse secondary to orthopaedic surgery in humans. Widrick and Fitts 35 reported a reduction of muscle fiber stiffness following a period of nonweight bearing in rats.…”

mentioning

confidence: 99%

Electromechanical Delay after ACL Reconstruction: An Innovative Method for Investigating Central and Peripheral Contributions

Kaneko

Onari²,

Kawaguchi³

et al. 2002

J Orthop Sports Phys Ther

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Objectives:The purpose of this study was to investigate the electromechanical properties of atrophied muscle in patients with anterior cruciate ligament (ACL) reconstruction and to examine the relationship of changes in these properties for a voluntarily elicited maximal isometric contraction and peripherally stimulated twitch contraction. Background: It is not known if, following ACL reconstruction, a prolonged reaction time to a sudden stimulus is due to impaired proprioception in the knee joint, a prolonged processing interval in the central nervous system, or a greater elasticity in the series elastic component of the quadriceps femoris. Methods: Seventeen patients were recruited 2 to 3 months following a unilateral ACL reconstruction. Both the involved leg (ACL-invo group) and the uninvolved leg (ACL-uninvo group) were studied. Twenty-two athletes (training group) and 18 control subjects (control group) were also tested. These subjects performed voluntary maximal isometric contraction (MVC) of the quadriceps femoris. Maximal twitch response was also elicited by a supramaximal electrical stimulation to the femoral nerve, and surface electromyograms were recorded from the vastus lateralis in all four groups. Results: Total reaction time for MVC in the ACL-invo group (250.47 ms) was prolonged compared to that of the control and training groups. Twitch response in the ACL-invo group (25.26 ms) was prolonged compared to that of the other three groups. Premotor time during both MVC and twitch response did not differ among the four groups. Electromechanical delay during MVC (53.62 ms) and the evoked electromechanical delay in twitch response (20.04 ms) were prolonged in the ACL-invo group as compared to the other three groups. Conclusions: Prolonged electromechanical delay in twitch response may be due to peripheral physiological disruptions (eg, stiffness of the series elastic component, changes of peripheral Science and Biomedical Engineering, Tsukuba, muscle fiber-type composition, or a decrease in function of the excitation-contraction coupling process). A prolonged electromechanical delay in twitch response can also explain the prolonged electromechanical delay observed for MVC. These findings suggest that prolonged total reaction time in MVC, when secondary to a visual stimulus in atrophied human quadriceps femoris muscle after ACL reconstruction, may be principally due to prolongation of electromechanical delay produced by peripheral physiological alterations. However, the contribution of premotor time to prolonged total reaction time was not revealed. Our results do not completely eliminate the possibility that central nervous system processing time and other neural factors are involved in the prolongation of reaction time. J Orthop Sports Phys Ther 2002;32:158-165.

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“…En estudios animales se evaluaron los efectos de la inmovilización del complejo grastrocnemius--soleus--aquiles en ratas [95] y los resultados fueron bastante drásticos.…”

Section: Efecto De La Inmovilización En La Unión Miotendinosaunclassified

“…Experimentos con animales, mostraron que la inmovilización durante cinco semanas resultó en una disminución del número de las fibras gruesas de colágeno, disminuyendo la media del diámetro de grosor de estas fibras [95].…”

Section: Efectos De La Inmovilización En El Tejido Tendinosounclassified

Análisis de los efectos de un protocolo de electroestimulación y ejercicios excéntricos, isométricos y concéntricos sobre el dolor y la funcionalidad en el tratamiento y readaptación de la tendinopatía rotuliana o rodilla del saltador

García¹

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Effect of disuse on the ultrastructure of the achilles tendon in rats

Cited by 83 publications

References 13 publications

Effects of chronic low frequency stimulation on contractile and elastic properties of hindlimb suspended rat soleus muscle

Effects of chronic low frequency stimulation on contractile and elastic properties of hindlimb suspended rat soleus muscle

Electromechanical Delay after ACL Reconstruction: An Innovative Method for Investigating Central and Peripheral Contributions

Análisis de los efectos de un protocolo de electroestimulación y ejercicios excéntricos, isométricos y concéntricos sobre el dolor y la funcionalidad en el tratamiento y readaptación de la tendinopatía rotuliana o rodilla del saltador

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