Biomedical Engineering Reference
In-Depth Information
However, these commercially available packages do not provide source code
access to users, which severely limits sharing of models, data exchange and the possi-
bility to extend the software capabilities [
50
]. In order to overcome these restrictions,
an open-source modeling and simulation platform called OpenSim was developed
as an extension of the musculoskeletal software package SIMM. The main aim of
this platform is to promote sharing and faster development of biomedical simula-
tions [
49
]. OpenSim not only provides modeling and analysis tools or the ability to
generate dynamic simulations but also makes the source code available. As a result,
the researcher is able to modify and adapt existing models created by other research
groups to fulfill his own research interests.
As a conclusion, it is important to mention that add-on implementations are con-
tinuously developed to complement and get around limitations of commercial and/or
non-commercial musculoskeletal modeling software packages. The aim is to achieve
an affordable and easy to use musculoskeletal modeling pipeline to advance research
on human locomotion and its clinical applications.
7.6 Musculoskeletal Simulations in Clinical Gait Analysis
in the Last Decade
SIMM, Anybody and OpenSim are currently the most widely used musculoskeletal
modeling software for dynamic simulations of movement in clinical gait research.
The next paragraphs present a brief overview of recent studies conducted with these
softwares. SIMMwas developed in the early 1990's byDelp and Loanwith the goal of
enabling scientists to develop, alter and evaluate different musculoskeletal models
with varying bone geometries and muscle-tendon parameters [
12
]. The following
paragraphs present examples of studies using SIMM.
Higginson and coworkers [
51
] studied the muscle coordination patterns of an indi-
vidual with post-stroke hemiparesis in comparison with healthy individuals during
walking. In this case, a muscle-actuated forward dynamic simulation was generated
of the patient and the healthy individuals. Subsequently, muscle forces were per-
turbed to determine the muscles contributing most to body weight support during
walking. The main conclusion of this study was that contributions of individual mus-
cles to body support during mid-stance are altered for an individual with post-stroke
hemiparesis compared to a healthy one. In this case musculoskeletal simulation is
advantageous in the sense that it may improve the understanding of muscle coordina-
tion in a special group suffering from hemiparesis. This, in the future, can influence
the rationale for therapeutic interventions.
In the study of cerebral palsy, musculoskeletal modeling has been used to calcu-
late the rectus femoris length and lengthening velocity in stiff knee gait in a children
population [
52
]. Although no statistically significant relation between different spas-
ticity levels and muscle-tendon length changes was detected, this study provided new
data on rectus femoris length and lengthening velocity changes during the phases of
gait.
