title: Cortical activation associated with muscle synergies of the human male pelvic floor.
abstract: Human pelvic floor muscles have been shown to operate synergistically with a wide variety of muscles, which has been suggested to be an important contributor to continence and pelvic stability during functional tasks. However, the neural mechanism of pelvic floor muscle synergies remains unknown. Here, we test the hypothesis that activation in motor cortical regions associated with pelvic floor activation are part of the neural substrate for such synergies. We first use electromyographic recordings to extend previous findings and demonstrate that pelvic floor muscles activate synergistically during voluntary activation of gluteal muscles, but not during voluntary activation of finger muscles. We then show, using functional magnetic resonance imaging (fMRI), that a region of the medial wall of the precentral gyrus consistently activates during both voluntary pelvic floor muscle activation and voluntary gluteal activation, but not during voluntary finger activation. We finally confirm, using transcranial magnetic stimulation, that the fMRI-identified medial wall region is likely to generate pelvic floor muscle activation. Thus, muscle synergies of the human male pelvic floor appear to involve activation of motor cortical areas associated with pelvic floor control.
authors.affiliation: Physical Therapy Department, Loma Linda University, Loma Linda, California 92350.
authors.forename: Skulpan
authors.initials: S
authors.lastname: Asavasopon
authors.affiliation: Division of Biokinesiology and Physical Therapy and.
authors.forename: Manku
authors.identifier: http://orcid.org/0000-0002-3645-312X
authors.initials: M
authors.lastname: Rana
authors.affiliation: Division of Biokinesiology and Physical Therapy and.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Kirages
authors.affiliation: Division of Biokinesiology and Physical Therapy and.
authors.forename: Moheb S
authors.initials: MS
authors.lastname: Yani
authors.affiliation: Division of Biokinesiology and Physical Therapy and Department of Neurology, University of Southern California, Los Angeles, California 90033.
authors.forename: Beth E
authors.initials: BE
authors.lastname: Fisher
authors.affiliation: Department of Radiology, University of Southern California, Los Angeles, California 90033.
authors.forename: Darryl H
authors.identifier: http://orcid.org/0000-0002-1111-9176
authors.initials: DH
authors.lastname: Hwang
authors.affiliation: Physical Therapy Department, Loma Linda University, Loma Linda, California 92350.
authors.forename: Everett B
authors.initials: EB
authors.lastname: Lohman
authors.affiliation: Physical Therapy Department, Loma Linda University, Loma Linda, California 92350, Department of Pathology and Human Anatomy, Loma Linda University, Loma Linda, California 92350, and.
authors.forename: Lee S
authors.identifier: http://orcid.org/0000-0002-3187-7126
authors.initials: LS
authors.lastname: Berk
authors.affiliation: Division of Biokinesiology and Physical Therapy and kutch@usc.edu.
authors.forename: Jason J
authors.identifier: http://orcid.org/0000-0002-2417-4879
authors.initials: JJ
authors.lastname: Kutch
mesh_terms: D000328:Adult; D004576:Electromyography; D005385:Fingers / Q000294:innervation / Q000502:physiology; D006801:Humans; D008297:Male; D009044:Motor Cortex / Q000502:physiology*; D009119:Muscle Contraction / Q000502:physiology; D018482:Muscle, Skeletal / Q000294:innervation / Q000502:physiology*; D017773:Pelvic Floor / Q000294:innervation / Q000502:physiology*; D050781:Transcranial Magnetic Stimulation; D055815:Young Adult
keywords: EMG; TMS; fMRI; motor cortex; pelvic floor; supplementary motor area