Adaptation of a Dynamic Muscle Mechanics Model to Simulate Movement in Young and Old Adults
Loading...
Authors
Loftin, G. Matthew
Issue Date
1998
Type
Thesis
Language
en_US
Keywords
Alternative Title
Abstract
The project I participated in involved the development of a direct-dynamics model to
realistically simulate human movement. The model consisted of a multi-segmented
representation of the body with Hill-type musculo-tendon actuators across the joints to
accurately reproduce muscle power and torque. My exclusive role was to help
validate/improve the model by generating simulations and comparing them with
experimental data obtained from human subjects during strength exercises. Through my
adjustments to muscle characteristics of the model, I was able to closely reproduce the
joint torque vs. joint angle curves created across the hip joint during specific
movements.
The model parameters of the Hill-type musculo-tendon model were then adjusted to
reflect changes in muscle mechanics that occur with aging. Adapting the muscle model
for older adults (-70 years old) involved: 1) Decreasing muscle cross-sectional areas,
maximum stress capability of the muscle, and maximum contraction velocity; 2) Slowing
muscular deactivation; 3) Increasing the relative force capacity during lengthening
contractions. The resulting model predicted diminished hip strength, power
development, and slowed torque development that were in agreement with experimental
observations of healthy older adults. This musculo-tendon model can then be used in
direct-dynamics simulations to predict how age-related changes in muscle may impact
the abilities of old adults to perform tasks requiring rapid movements and/or substantial
strength.
Description
36 p.
Citation
Publisher
License
U.S. copyright laws protect this material. Commercial use or distribution of this material is not permitted without prior written permission of the copyright holder. All rights reserved.