Changes in motoneurone firing rates during sustained maximal voluntary contractions.
نویسندگان
چکیده
منابع مشابه
Reduced voluntary drive during sustained but not during brief maximal voluntary contractions in the first dorsal interosseous weakened by spinal cord injury.
In able-bodied (AB) individuals, voluntary muscle activation progressively declines during sustained contractions. However, few data are available on voluntary muscle activation during sustained contractions in muscles weakened by spinal cord injury (SCI), where greater force declines may limit task performance. SCI-related impairment of muscle activation complicates interpretation of the inter...
متن کاملMotor-unit discharge rates in maximal voluntary contractions of three human muscles.
Single motor-unit firing rates have been recorded during maximal voluntary contractions using tungsten microelectrodes. Over 300 units from four subjects were sampled from each of three muscles. These were the biceps brachii, adductor pollicis, and soleus, chosen because of known differences in their fiber-type composition and contractile properties. In all cases the contraction maximality was ...
متن کاملDelayed depolarization and firing behavior of human motoneurons during voluntary muscle contractions
INTRODUCTION The firing behavior of motoneurons is governed by the interaction between the intrinsic properties of motoneurons and the synaptic inputs that they receive. In particular, long-lasting afterhyperpolarization (AHP) following each motoneuron spike and thus decreasing motoneuron excitability immediately after spike was found to be a key mechanism in controlling of interspike interval ...
متن کاملSustained Maximal Voluntary Contraction Produces Independent Changes in Human Motor Axons and the Muscle They Innervate
The repetitive discharges required to produce a sustained muscle contraction results in activity-dependent hyperpolarization of the motor axons and a reduction in the force-generating capacity of the muscle. We investigated the relationship between these changes in the adductor pollicis muscle and the motor axons of its ulnar nerve supply, and the reproducibility of these changes. Ten subjects ...
متن کاملDetermining central activation failure and peripheral fatigue in the course of sustained maximal voluntary contractions: a model-based approach.
In the study of fatigue, several methods have been used to calculate the development of central activation failure (CAF) and peripheral fatigue (PF) in the course of a sustained maximal voluntary contraction (MVC). This paper presents a model that enables simultaneous determination of CAF and PF during sustained MVC by using only force registration and superimposed electrical stimulation. In th...
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ژورنال
عنوان ژورنال: The Journal of Physiology
سال: 1983
ISSN: 0022-3751
DOI: 10.1113/jphysiol.1983.sp014765