Title: “Exploring pelvic floor muscle sparing in individuals with spinal cord injury using pelvic floor training exercises and transcranial magnetic stimulation”
Thesis Supervisor: Dr. Tania Lam (Kinesiology)
Committee members: Dr. Mark Carpenter (Kinesiology), Dr Lynn Stothers (Urologic Sciences)
Chair: Dr. Moss Norman (Kinesiology)
Background: The pelvic floor muscles (PFM) are crucial in maintaining urinary continence. Damage and denervation to this muscle group is associated with urine leakage. In able-bodied individuals, exercise programs intended to strengthen the core and PFM are considered the first line of treatment against urinary incontinence. However, limited research has explored applying these exercises to people with spinal cord injury (SCI), where more than 80% of individuals experience bladder dysfunction. PFM training programs may not have been attempted in people with SCI because of assumptions about remaining PFM function post-injury. Further, for those with high-thoracic motor-complete SCI (mc-SCI), it is often incorrectly assumed that they are unable to engage muscles of the core based on standard neurological assessment. Evidence from previous work has already shown that sparing in abdominal function can be detected using manual palpation, surface electromyography, and transcranial magnetic stimulation. It remains unknown to what extent the PFM may be similarly spared in this population.
Objectives: To a) characterize and compare activation patterns of pelvic floor, abdominal, and gluteal muscles during validated PFM training exercises in able-bodied individuals and those with mc-SCI and b) evaluate corticospinal excitability to the PFM via transcranial magnetic stimulation.
Methods: This study will use a two-part cross-sectional design. In both parts, EMG recordings will be taken bilaterally from rectus abdominis, external oblique, erector spinae, levator ani, and gluteus maximus muscles. In Part 1, participants will attempt a variety of validated maneuvers to attempt to elicit PFM activity. In Part 2, participants will receive transcranial magnetic stimulation targeting the pelvic floor.
Results: Our results show that voluntary activation is possible for all AB and the majority of SCI participants. For AB participants, Kegels and gluteal contractions elicited the largest responses, but for SCI participants, abdominal exercises elicited the largest responses. MEPs were elicited in the PFM for all AB subjects and all but two SCI participants.
Conclusion: Our results suggest that those with mc-SCI retain functional sparing to the PFM after injury. This supports the application of PFM training programs to this population.