Biomechanical parameters of the elbow stretch reflex in chronic hemiparetic stroke

Jacob G. McPherson, Arno H.A. Stienen, Brian D. Schmit, Julius P.A. Dewald*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

1 Scopus citations

Abstract

We sought to determine the relative velocity sensitivity of stretch reflex threshold angle and reflex stiffness during stretches of the paretic elbow joint in individuals with chronic hemiparetic stroke, and to provide guidelines to streamline spasticity assessments. We applied ramp-and-hold elbow extension perturbations ranging from 15 to 150°/s over the full range of motion in 13 individuals with hemiparesis. After accounting for the effects of passive mechanical resistance, we modeled velocity-dependent reflex threshold angle and torque–angle slope to determine their correlation with overall resistance to movement. Reflex stiffness exhibited substantially greater velocity sensitivity than threshold angle, accounting for ~ 74% (vs. ~ 15%) of the overall velocity-dependent increases in movement resistance. Reflex stiffness is a sensitive descriptor of the overall velocity-dependence of movement resistance in spasticity. Clinical spasticity assessments can be streamlined using torque–angle slope, a measure of reflex stiffness, as their primary outcome measure, particularly at stretch velocities greater than 100°/s.

Original languageEnglish (US)
Pages (from-to)121-135
Number of pages15
JournalExperimental Brain Research
Volume237
Issue number1
DOIs
StatePublished - Jan 31 2019

Keywords

  • Joint torque
  • Movement resistance
  • Spasticity
  • Stretch reflex
  • Stroke
  • Threshold angle

ASJC Scopus subject areas

  • Neuroscience(all)

Fingerprint Dive into the research topics of 'Biomechanical parameters of the elbow stretch reflex in chronic hemiparetic stroke'. Together they form a unique fingerprint.

Cite this