Medical College of Wisconsin
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Biomechanical and reflex responses to joint perturbations during electrical stimulation of muscle: instrumentation and measurement techniques. Med Biol Eng Comput 1994 May;32(3):261-72

Date

05/01/1994

Pubmed ID

7934249

DOI

10.1007/BF02512521

Scopus ID

2-s2.0-0028437062 (requires institutional sign-in at Scopus site)   11 Citations

Abstract

A test device is developed to measure ankle joint compliance and muscle activity when the ankle is subjected to perturbations in angular position (or torque) from bias positions achieved volitionally or via electrical stimulation. The ankle measurement system uses a pivoting footplate and is operable with the subject sitting or supine. A companion platform for the knee is developed that uses a rotary arm and attached leg brace and is operable with the subject's leg in the horizontal or vertical plane. The knee fixture's pivoting arm can slide to account for the cam-like movement of the knee during rotation. The devices use similar hardware and share common instrumentation and control. Precise torque or position perturbations are delivered by a computer-controlled torque motor to the ankle or knee. Angular displacement, torque, acceleration, knee fixture moment arm and electromyographic data are collected on analogue tape and simultaneously digitised and stored. A special stimulator/recording amplifier permits the recording of electromyographic signals from the stimulated muscle. Experimental data indicate that the ankle and knee devices, operated horizontally, are purely inertial systems. Sample ankle and knee joint responses to perturbations are presented.

Author List

Robinson CJ, Flaherty B, Fehr L, Agarwal GC, Harris GF, Gottlieb GL

Authors

Gerald F. Harris Emeritus Professor in the Orthopaedic Surgery department at Medical College of Wisconsin
Gerald Harris PhD Director in the Orthopaedic Research Engineering Center (OREC) department at Marquette University




MESH terms used to index this publication - Major topics in bold

Ankle Joint
Biomechanical Phenomena
Electric Stimulation Therapy
Electromyography
Electronics, Medical
Humans
Knee Joint
Muscles
Reflex