Evaluating a novel MR-compatible foot pedal device for unipedal and bipedal motion: Test–retest reliability of evoked brain activity

Jade D. Doolittle, Ryan J. Downey, Julia P. Imperatore, Logan T. Dowdle, Daniel H. Lench, John McLeod, Daniel M. McCalley, Chris M. Gregory, Colleen A. Hanlon

Research output: Contribution to journalArticlepeer-review


The purpose of this study was to develop and evaluate a new, open-source MR-compatible device capable of assessing unipedal and bipedal lower extremity movement with minimal head motion and high test–retest reliability. To evaluate the prototype, 20 healthy adults participated in two magnetic resonance imaging (MRI) visits, separated by 2–6 months, in which they performed a visually guided dorsiflexion/plantar flexion task with their left foot, right foot, and alternating feet. Dependent measures included: evoked blood oxygen level-dependent (BOLD) signal in the motor network, head movement associated with dorsiflexion/plantar flexion, the test–retest reliability of these measurements. Left and right unipedal movement led to a significant increase in BOLD signal compared to rest in the medial portion of the right and left primary motor cortex (respectively), and the ipsilateral cerebellum (FWE corrected, p <.001). Average head motion was 0.10 ± 0.02 mm. The test–retest reliability was high for the functional MRI data (intraclass correlation coefficients [ICCs]: >0.75) and the angular displacement of the ankle joint (ICC: 0.842). This bipedal device can robustly isolate activity in the motor network during alternating plantarflexion and dorsiflexion with minimal head movement, while providing high test–retest reliability. Ultimately, these data and open-source building instructions will provide a new, economical tool for investigators interested in evaluating brain function resulting from lower extremity movement.

Original languageEnglish (US)
Pages (from-to)128-138
Number of pages11
JournalHuman Brain Mapping
Issue number1
StatePublished - Jan 2021

Bibliographical note

Funding Information:
Research reported in this publication was supported by an Institutional Development Award (IDeA) from the National Institute of General Medical Sciences (P20GM109040) and support from the National Institutes of Health National Center of Neuromodulation for Rehabilitation (P2CHD0886844). The contents are solely the responsibility of the authors and do not necessarily represent the official views of the NIH or NICHD.


  • bipedal movement
  • brain activity
  • fMRI
  • lower extremity
  • motor impairment
  • MR-compatible device
  • rehabilitation

PubMed: MeSH publication types

  • Journal Article

Fingerprint Dive into the research topics of 'Evaluating a novel MR-compatible foot pedal device for unipedal and bipedal motion: Test–retest reliability of evoked brain activity'. Together they form a unique fingerprint.

Cite this