Abstract：
:This study exploited the alterations in pedal speed and joints kinematics elicited by changing crank length (CL) to test how altered task mechanics during cycling will modulate the muscle activation characteristics in human rectus femoris (RF), biceps femoris long head (BF), soleus (SOL) and tibialis anterior (TA). Kinetic (torque), kinematic (joint angle) and muscle activity (EMG) data were recorded simultaneously from both legs of 10 healthy adults (aged 20-38 years) during steady-state cycling at ~60 rpm and 90-100 W with three symmetrical CLs (155 mm, 175 mm and 195 mm). The CL elongation (DeltaCL) resulted in similar increases in the knee joint angles and angular velocities during extension and flexion, whilst the ankle joint kinematics was significantly influenced only during extension. DeltaCL resulted in significantly reduced amplitude and prolonged duration of BF EMG, increased mean SOL and TA EMG amplitudes, and shortened SOL activity time. RF activation parameters and TA activity duration were not significantly affected by DeltaCL. Thus total SOL and RF EMG activities were similar with different CLs, presumably enabling steady power output during extension. Higher pedal speeds demand an increased total TA EMG activity and decreased total BF activity to propel the leg through flexion into extension with a greater degree of control over joint stability. We concluded that the proprioceptive information about the changes in the cycling kinematics is used by central neural structures to adapt the activation parameters of the individual muscles to the kinetic demands of the ongoing movement, depending on their biomechanical function.
journal_name
Exp Brain Resjournal_title
Experimental brain researchauthors
Mileva K,Turner Ddoi
10.1007/s00221-003-1561-ykeywords:
subject
Has Abstractpub_date
2003-10-01 00:00:00pages
393-403issue
3eissn
0014-4819issn
1432-1106journal_volume
152pub_type
杂志文章abstract：:We studied the effects of morphine injected either systemically or into the dorsal periaqueductal gray (DPAG) or nucleus accumbens (NA) using conventional and ethological analyses of behavior of rats submitted to the elevated plus-maze test with transparent walls. Intraperitoneal morphine (0.1 mg/kg and 0.3 mg/kg) inc...
journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/s002210050896
更新日期：1999-11-01 00:00:00
abstract：:The blocking effect of triethyldodecylammoniumbromide (TEA-C12), applied locally to the sciatic nerve, was studied in 28 adult BDF1 mice. Clinical parameters, electrophysiological recordings of muscle action potentials evoked by stimulation at the sciatic notch, and morphological aspects are presented. Our results sho...
journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/BF00248862
更新日期：1989-01-01 00:00:00
abstract：:Intradermal injection of capsaicin results in sensitization of spinothalamic tract cells to brushing and pressure applied to the cutaneous receptive field in anesthetized monkeys. A significant increase in background activity also occurs immediately after capsaicin injection that lasts for at least 2 h. A 40-50% decre...
journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/pl00005675
更新日期：1997-06-01 00:00:00
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journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/BF00237283
更新日期：1984-01-01 00:00:00
abstract：:The afternystagmus that occurs in the dark after gaze fixation during optokinetic stimulation is directed in the opposite direction relative to the previous optokinetic stimulus. The mechanism responsible for such afternystagmus after suppression of optokinetic nystagmus (ASOKN) is unclear. Several hypotheses have bee...
journal_title：Experimental brain research
pub_type： 杂志文章,随机对照试验
doi：10.1007/s00221-014-3971-4
更新日期：2014-09-01 00:00:00
abstract：:The tectofugal pathway in birds has been reported to process primarily information from the contralateral eye. Although this pathway has access to the contralateral hemisphere by various connections, electrophysiological recordings up to now have failed to demonstrate any excitatory influence of visual stimulation in ...
journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/BF00271850
更新日期：1988-01-01 00:00:00
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journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/s00221-019-05628-6
更新日期：2019-11-01 00:00:00
abstract：:Our perception of the vertical depends on allocentric information about the visual surrounds, egocentric information about the own body axis and gravicentric information about the pull of gravity. Previous work has documented that some individuals rely strongly on allocentric information, while others do not, and the ...
journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/s00221-015-4526-z
更新日期：2016-04-01 00:00:00
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journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/s00221-010-2178-6
更新日期：2010-05-01 00:00:00
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journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/BF00235311
更新日期：1985-01-01 00:00:00
abstract：:1. The activity of cat semicircular canal and otolith afferents was studied during yaw and roll rotations, respectively, to examine their dynamic behavior. 2. A sinusoidal analysis of the canal afferent activities showed that their dynamic characteristics are similar to those of second order vestibular neurons, except...
journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/BF00239549
更新日期：1978-08-15 00:00:00
abstract：:At a descriptive level, prehension movements can be partitioned into three components ensuring, respectively, the transport of the arm to the vicinity of the target, the orientation of the hand according to object tilt, and the grasp itself. Several authors have suggested that this analytic description may be an opera...
journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/BF00228557
更新日期：1996-07-01 00:00:00
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journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/s00221-007-1014-0
更新日期：2007-10-01 00:00:00
abstract：:Efferent and afferent connections of the visually responsive cortex (area anteromedial, AM) located in the anterior portion of area 18b were studied with degeneration and horseradish peroxidase (HRP) methods following small lesions and HRP injections into this area. Degenerating axons, terminals and retrogradely HRP-l...
journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/BF00237996
更新日期：1984-01-01 00:00:00
abstract：:Norepinephrine (NE)-induced, long-lasting facilitation of the perforant path evoked population spike amplitude in the dentate gyrus (DG) has been reported to occur following iontophoresis of norepinephrine in the DG in vivo and following application of 10 or 20 microM NE to the hippocampal slice in vitro. The present ...
journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/BF00235656
更新日期：1986-01-01 00:00:00
abstract：:Most studies of rapid orienting gaze shifts generated by combined eye and head movements have focused on an experimental condition in which gaze displacements are started with the subject's eyes in the normal straight-ahead position in the orbit. Such an experimental approach does not permit a clear identification of ...
journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/BF00230204
更新日期：1993-01-01 00:00:00
abstract：:Goal-directed movements are commonly used to allow humans to interact with their environment. When making a goal-directed movement in a natural environment, there are many competing stimuli. It is therefore important to understand how making a goal-directed movement could be impacted by the need to divide attention be...
journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/s00221-014-3880-6
更新日期：2014-06-01 00:00:00
abstract：:Studies on motor learning typically present a constant adaptation stimulus, corresponding to the desired final adaptive state. Studies of the auditory and optokinetic systems provide compelling evidence that neural plasticity is enhanced when the error signal driving adaptation is instead adjusted gradually throughout...
journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/s00221-008-1537-z
更新日期：2008-12-01 00:00:00
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journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/s002219900220
更新日期：2000-01-01 00:00:00
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journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/s00221-014-3991-0
更新日期：2014-10-01 00:00:00
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journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/BF00228906
更新日期：1989-01-01 00:00:00
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journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/BF00230256
更新日期：1989-01-01 00:00:00
abstract：:When humans pursue motion stimuli composed of alternating constant velocity segments of randomised duration (RD), they nevertheless initiate anticipatory eye deceleration before stimulus direction changes at a pre-programmed time based on averaging prior stimulus timing. We investigated, in both the time and frequency...
journal_title：Experimental brain research
pub_type： 杂志文章,随机对照试验
doi：10.1007/s00221-011-2725-9
更新日期：2011-07-01 00:00:00
abstract：:Observations of neurons in dorsal horn laminae IV-VI of the lumbosacral segments of Golgi-stained spinal cords in kittens and adult cats revealed laminar differences in dendritic architecture. Many neurons in lamina IV had dense, bushy dendritic fields. Lamina V contained, in addition to bushy cells similar in appeara...
journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/BF00237093
更新日期：1977-05-23 00:00:00
abstract：:The firing patterns of alpha and gamma efferent fibres and of group I and group II afferent fibres innervating the gastrocnemius muscle were observed during spontaneous locomotor movements in the thalamic cat. Multi-unit discharges of each kind of fibre were obtained by electronic sorting of the action potentials from...
journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/BF00340493
更新日期：1986-01-01 00:00:00
abstract：:The responses of 192 single units in the cat's pulvinar-complex, comprising the inferior, medial and lateral pulvinar nuclei, were studied in paralysed cats, lightly anaesthetized with N2O/O2 supplemented with pentobarbitone. About 60% of the cells were visually driven and their receptive fields classified as either d...
journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/BF00235804
更新日期：1978-01-18 00:00:00
abstract：:Automatic postural responses of leg muscles to the sudden displacement of standing support were investigated under four different conditions of information given to subjects in advance. Results from three groups of subjects were compared: 6 normal subjects, 10 patients with cerebellar disease, and 9 patients with Park...
journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/BF00231777
更新日期：1991-01-01 00:00:00
abstract：:The aim of this work was to study the neurochemical effects in the brain of GABA-transaminase inhibition by systemic administration of gabaculine (100 mg/kg, i.a.) in the rat. In order to investigate neurotransmitter and related amino-acid compartmentation and metabolism, we have developed an original tool: the coupli...
journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/s002210050802
更新日期：1999-08-01 00:00:00
abstract：:Knowing when the head moves is crucial information for the central nervous system to maintain a veridical representation of the self in the world for perception and action. Previous studies have shown that active head movement onset has to precede a sound by approximately 80 ms to be perceived as simultaneous, suggest...
journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/s00221-017-5026-0
更新日期：2017-10-01 00:00:00
abstract：:The praxis system comprises a network of brain regions dedicated to complex skilled movements. Following suggestions of a female advantage on learned movements (Chipman and Hampson in Neuropsychologia 44(12):2315-2329, 2006), we investigated how males and females acquire skilled movements. Subjects viewed and imitated...
journal_title：Experimental brain research
pub_type： 杂志文章
doi：10.1007/s00221-010-2351-y
更新日期：2010-08-01 00:00:00
