Ultrasound for Quantifying Muscle Activation Elicited by Spinal Cord Stimulation and Functional Electrical Stimulation

Summary

Transcutaneous (non-invasive) spinal cord stimulation (tSCS) has been shown to facilitate volitional motor activity in patients with spinal cord injury. tSCS is known to activate the same neural structures as invasive SCS, meaning it may have the potential for functional restoration without an expensive surgical implant. Functional electrical stimulation (FES) is also used in therapy for patients with spinal cord injury to locally activate paralyzed or weakened muscles. There is evidence that combining FES and tSCS may elicit greater muscle activation than either modality alone. The objective of this study is to quantify the torque at the ankle joint generated by tSCS, by FES, and by tSCS + FES. Additionally, ultrasound images will be collected during stimulation to provide a metric of muscle activity. The correlation between ultrasound and torque will be assessed to determine if ultrasound is a useful modality for quantifying tSCS-elicited muscle activity.

Eligibility

Age range

18–60 years

Sex

All

Healthy volunteers

Yes

Interventions

• Device
  Functional Electrical Stimulation

  Functional electrical stimulation will be applied to the ankle muscles. The resulting torque will be collected, and ultrasound data will be obtained during stimulation.

• Device
  Transcutaneous (Non-Invasive) Spinal Cord Stimulation

  Non-invasive spinal cord stimulation will be applied. The resulting torque data will be collected, and ultrasound data will be obtained during stimulation.

• Device
  Ultrasound

  Ultrasound data will be collected from the shin muscles during FES and tSCS.

Location