A Tendon Indentation Method to Quantify Velocity-Dependent Reflex Responses after Hemispheric Stroke

Taimoor Afzal, William Z. Rymer, Nina L. Suresh*

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Stretch reflex responses in passive muscle can be utilized to assess spasticity in chronic stroke survivors. In this study, we present a different method of eliciting the reflex response by imposing tendon indentation using a linear motor. Specifically, we test a "Ramp-and-hold" protocol, utilizing a linear motor controlled by a position-controlled feedback loop (Linmot, Inc), to indent the biceps brachii distal tendon at different velocities. The protocol was tested on the affected arm of three stroke subjects. We also utilized a tendon indentation combined with tendon-tapping method to quantify the reflex threshold. Our results indicate that the reflex response was elicited at velocities equal to or above 50 mm/s in 2/3 subjects. No reflex response was detected in one subject. All subjects showed a distinct reflex threshold using the indentation/tapping method. Furthermore, the presence of a reflex response during tendon-tapping was not necessarily accompanied by the elicitation of a reflex response during the ramp-and-hold. However, our data suggests that the indentation threshold during tapping is correlated to the presence of a reflex response at the velocities tested during the ramp-and-hold. Though more time consuming, tendon indentation using ramp-and-hold could provide greater resolution of the reflex response to quantify spasticity than the current clinically employed ballistic tapping method using a reflex hammer.

Original languageEnglish (US)
Title of host publication2019 41st Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBC 2019
PublisherInstitute of Electrical and Electronics Engineers Inc.
Pages5221-5224
Number of pages4
ISBN (Electronic)9781538613115
DOIs
StatePublished - Jul 2019
Event41st Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBC 2019 - Berlin, Germany
Duration: Jul 23 2019Jul 27 2019

Publication series

NameProceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS
ISSN (Print)1557-170X

Conference

Conference41st Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBC 2019
CountryGermany
CityBerlin
Period7/23/197/27/19

ASJC Scopus subject areas

  • Signal Processing
  • Biomedical Engineering
  • Computer Vision and Pattern Recognition
  • Health Informatics

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