Bibliothek

feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
  • 1
    Digitale Medien
    Digitale Medien
    Springer
    Experimental brain research 76 (1989), S. 510-518 
    ISSN: 1432-1106
    Schlagwort(e): Heteronymous Ia facilitation ; Presynaptic inhibition ; Reciprocal inhibition ; Monosynaptic reflex ; Voluntary movement ; Human
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Variations of presynaptic inhibition in heteronymous Ia fibres projecting to soleus motoneurones were studied during the first 250 ms of phasic voluntary isometric contractions of the antagonist tibialis anterior muscle in human subjects. During the first 60–80 ms of TA e.m.g activity, presynaptic inhibition was often more marked than at rest, but not in all experimental sessions. After 60–80 ms, presynaptic inhibition was always increased compared to rest and to the onset of TA e.m.g. activity. A “rebound” in femoral nerve induced Ia facilitation was often observed between 90–150 ms. The early increase in presynaptic inhibition was widespread and non specific since it was observed at the onset of extensor carpi radialis contractions of maximal strength. The “rebound” in heteronymous Ia facilitation was interpreted as a relative decrease in presynaptic inhibition to which nonspecific suprasegmental and cutaneous effects contributed. The late increase in presynaptic inhibition in Ia fibers to soleus motoneurones was considered as reciprocally inhibiting the Sol H-reflex, thus counteracting the phasic stretch of the antagonist muscle during TA contraction.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 2
    Digitale Medien
    Digitale Medien
    Springer
    Experimental brain research 42 (1981), S. 351-361 
    ISSN: 1432-1106
    Schlagwort(e): Cutaneous afferents ; Ib effects ; Locomotion ; Man
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Variations in the H-reflex of soleus (Sol), quadriceps (Q) and short head of biceps femoris (Bi) muscles in normal man were used to investigate the effect of volleys in low threshold cutaneous afferents from the ipsilateral limb on transmission of Ib effects from ankle and Q muscles to these different motoneurone (MN) pools. Stimulation of cutaneous afferents from the foot sole and the toes (but not from the thigh, knee or calf), which did not modify the size of the test reflexes when applied alone, strongly depressed Ib reflex pathways to MNs supplying muscles operating at the knee. The very brief central latency of this depression suggests that tactile cutaneous afferents from the foot have oligosynaptic spinal connexions with the interneurones intercalated in the Ib pathways to MNs. The same cutaneous stimuli did not at all modify Ib inhibition of Sol MNs from triceps surae. These findings are discussed with regard to the role of the different muscles in human locomotion. It is suggested that during the stance phase of heel bipedal locomotion, the cutaneous depression of Ib reflex pathways to MNs supplying muscles operating at the knee might operate in association with the strong Ia connexions from ankle to knee muscles described in the previous paper.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...