Spinal motor preparation in humans

Frank, James S.

doi:10.1016/0013-4694(86)90021-0

Cited by 29 publications

(6 citation statements)

References 23 publications

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“…The present findings are similar to the changes that occur when subjects are provided with a warning that a stimulus to which they must respond is imminent (Burke, McKeon, Skuse & Westerman, 1980). 'Anticipation' is associated with changes in gain of spinal reflexes (Burke et al 1980;Gerilovsky, Struppler, Altmann & Velho, 1983;Frank, 1986;Yamamoto & Ohtsuki, 1989) and muscles are often tensed unintentionally in preparation for the command signal to move. There is, however, no evidence that anticipation activates fusimotor neurones selectively or preferentially as a means of priming central circuits prior to the need to move (Burke et al 1980;Gerilovsky et al 1983), much as is the case with mental rehearsal of movement.…”

Section: Discussionsupporting

confidence: 72%

Mental rehearsal of motor tasks recruits α‐motoneurones but fails to recruit human fusimotor neurones selectively

Gandevia

Wilson

Inglis

et al. 1997

The Journal of Physiology

105

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As mental rehearsal of movements activates multiple cortical areas associated with movement, we assessed whether this increases fusimotor drive and whether enhanced muscle spindle activity could contribute to the improvement in skill that accompanies mental rehearsal. Microneurographic recordings were made from six muscle spindle afferents innervating extensor muscles in the forearm or tibialis anterior, which were selected because their discharge increased during very weak contractions. Activity was monitored while subjects imagined performing a range of activities including simple and complex movements involving the relevant muscles. No activation of muscle spindle afferents occurred during imagined motor tasks without EMG. When the relevant muscles contracted during mental rehearsal, spindle discharge increased, much as in weak contractions. Mental rehearsal increased background EMG in the involved muscles and also increased H reflex amplitude independently of EMG changes. Although there was no evidence for selective fusimotor activation during imagined movement, skeletomotor activity and reflex excitability increased. Similar changes occur with preparation for movement following a cue. It is likely that mental rehearsal usually involves unintentional performance of the planned motor task.

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Section: Discussionsupporting

confidence: 72%

Mental rehearsal of motor tasks recruits α‐motoneurones but fails to recruit human fusimotor neurones selectively

Gandevia

Wilson

Inglis

et al. 1997

The Journal of Physiology

105

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“…The testing leg was secured by a Velcro strap around the foot to maintain a fixed position on the platform attached to the compressor system. It is known that the excitability of motor neurons is influenced by central set, characterized as the “preparatory set” within the central nervous system before execution of a motor act (Frank, 1986; Meunier and Pierrot-Deseilligny, 1989; Leis et al, 1995). The central set is affected by many factors such as environmental noise (Delwaide and Schepens, 1995; Kolev and Milanov, 1995), the level of arousal and anxiety(Ribot-Ciscar et al, 2000; Rossi-Durand, 2002; Sibley et al, 2007), body position (Hayashi et al, 1992; Mynark and Koceja, 1997; Phadke et al, 2006), and sensory inputs (Iles and Pisini, 1992b; Hoffman and Koceja, 1995; Iles, 1996; Knikou, 2007; Conway and Knikou, 2008).…”

Section: Methodsmentioning

confidence: 99%

Limb segment load inhibits post activation depression of soleus H-reflex in humans

Tseng

Shields

2012

Clinical Neurophysiology

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Objective We investigated the effect of various doses of limb segment load on soleus H-reflex amplitude and post activation depression in healthy individuals. We also explored the influence of limb segment load on spinal circuitry in one individual with chronic SCI. Methods 28 healthy adults and one SCI subject received compressive loads applied to the top of their knee at varied doses of load (10%, 25%, and 50% of the body weight). Soleus H-reflexes were measured before (baseline) and during the loading phase. Results There were no significant differences in H-reflex amplitudes during the 50 % BW load-on phase as compared to either baseline session or the load-off phase. However, the post activation depression was decreased over 9% (p < 0.05) during the load-on phase compared to the load-off phase and scaled according to load (50%>25%>10%). The post activation depression ratio also appears less responsive to varying loads after chronic SCI. Conclusions Limb segment load decreases post-activation depression in humans. These findings suggest that the mechanism associated with post activation depression is modulated by limb segment load, and may be influenced by spinal reorganization after SCI. Significance Future studies will determine if various levels of spasticity modulate the response of limb segment load on post activation depression in those with acute and chronic SCI.

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“…About 100 ms before the onset of intentional movements, the transmission of kinesthetic input in the dorsal column/ medial lemnical pathway is inhibited (Coulter, 197 4;Ghez & Pisa, 1972). At roughly the same time, transmission in spinal reflex pathways appears to be facilitated (Coquery & Coulmance, 1971;Frank, 1986;Riedo & Ruegg, 1988). Based on the data of Allen and Tsukahara (197 4 ), Evarts, Shinoda, and Wise (1984) hypothesized that, during transitions from static to dynamic limb postures, kinesthetic input from the cerebellum to the cerebral cortex is "gated" from the interpositus nucleus to the dentate nucleus.…”

Section: Discussionmentioning

confidence: 96%

“…Spinal reflex pathways are facilitated approximately 80 ms be-. fore the initiation of a targeted movement (Coquery & Coulmance, 1971;Frank, 1986;Riede & Ruegg, 1988), and initialization and triggering precede this increase in reflex excitability (Eichenberger & Ruegg, 1984 ). Thus, just before.…”

mentioning

confidence: 93%

Time-Dependent Effects of Kinesthetic Input

Cordo¹,

Flanders²

1990

Journal of Motor Behavior

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Sensory input can be used by the nervous system to control the spatial parameters of motor responses (e.g., distance, velocity, and direction) by initializing these parameters before movement onset and then by adjusting these parameters during movement. Sensory input can also be used to trigger movements. In the experiments reported in this paper, we compared the effects of kinesthetic input on a triggered motor response when the kinesthetic input was generated at different times relative to the onset of the motor response. Human subjects responded to a visual stimulus by intentionally increasing elbow torque to a target level. Kinesthetic input was generated by unexpectedly rotating each subject's elbow 100 ms before the onset of the intentional torque response (early) or coincident with the onset of the intentional torque response (late). The effect of early kinesthetic input on the intentional torque response markedly differed from the effect of late kinesthetic input. The effect of early kinesthetic input was relatively independent of the direction of elbow rotation, had a different dependence on the amplitude of rotation, and required a shorter duration of rotation compared to the effect of late kinesthetic input. These differences in the effects of early and late kinesthetic input might be related to the initialization, triggering, and adjustment of motor responses.

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Spinal motor preparation in humans

Cited by 29 publications

References 23 publications

Mental rehearsal of motor tasks recruits α‐motoneurones but fails to recruit human fusimotor neurones selectively

Mental rehearsal of motor tasks recruits α‐motoneurones but fails to recruit human fusimotor neurones selectively

Limb segment load inhibits post activation depression of soleus H-reflex in humans

Time-Dependent Effects of Kinesthetic Input

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