An fMRI Study of the Differences in Brain Activity During Active Ankle Dorsiflexion and Plantarflexion

Abstract

Little is known regarding the differences in active cortical and subcortical systems during opposing movements of an agonist-antagonist muscle group. The objective of this study was to characterize the differences in cortical activation during active ankle dorsiflexion and plantarflexion using functional MRI (fMRI). Eight right-handed healthy adults performed auditorily cued right ankle dorsiflexions and plantarflexions during fMRI. Differences in activity patterns between dorsiflexion and plantarflexion during fMRI were assessed using between- and within-subject voxel-wise t-tests. Results indicated that ankle dorsiflexion recruited significantly more regions in left M1, the supplementary motor area (SMA) bilaterally, and right cerebellum. Both movements activated similar left hemisphere regions in the putamen and thalamus. Dorsiflexion activated additional areas in the right putamen. Results suggest that ankle dorsiflexion and plantarflexion may be controlled by both shared and independent neural circuitry. This has important implications for functional investigations of gait pathology and how rehabilitation may differentially affect each movement.

Functional and Structural Correlates of Motor Speed in the Cerebellar Anterior Lobe

“…In investigating this assumption, the first challenge we encountered was the identification of speed specific brain regions. According to former studies which characterized brain activity during repeated dorsi- and plantarflexions, we expected activity in the lower leg and foot representation of the supplementary and primary motor cortex of the contralateral brain hemisphere [32], [51], [52]. Besides that a bilateral subcortical activity could have been expected in the putamen, thalamus and cerebellum [51], [52].…”

“…According to former studies which characterized brain activity during repeated dorsi- and plantarflexions, we expected activity in the lower leg and foot representation of the supplementary and primary motor cortex of the contralateral brain hemisphere [32], [51], [52]. Besides that a bilateral subcortical activity could have been expected in the putamen, thalamus and cerebellum [51], [52]. Independent of condition we most notably found brain activity in the supplementary motor cortex, the primary motor cortex and in the cerebellum, which is in accordance with the studies mentioned above.…”

Specific brain activation patterns associated with two neuromuscular electrical stimulation protocols

“…The voluntary protocol resulted in an increased activity of controlateral primary and sensory motor cortices as previously described for plantar flexions 29–32 . In addition, we observed a bilateral activation in the visual cortex and cerebellum associated with an increased activity in contralateral subcortical regions - potentially related to the experimental design that required active visuomotor coordination 26, 33, 34 .…”

Brain Activity during Mental Imagery of Gait Versus Gait-Like Plantar Stimulation: A Novel Combined Functional MRI Paradigm to Better Understand Cerebral Gait Control

“…Current fMRI studies of gait control have focused on either somatosensory or cognitive processing, but not on their interaction. For instance, brain activity during active or passive ankle dorsi- and plantarflexion, a critical component of gait (Dobkin et al, 2004), has been explored using fMRI (Dobkin et al, 2004; Sahyoun et al, 2004; Trinastic et al, 2010), however, this single joint movement is only one part of the complex gait cycle and does not induce the same degree of cognitive load.…”