The goal of this work is to provide a scientific basis for the treatment
of crouch gait, one of the most prevalent and troublesome movement
abnormalities among children with cerebral palsy. Crouch gait is characterized
by excessive knee flexion during stance, which is usually accompanied
by exaggerated flexion, adduction, and internal rotation of the hip.
Excessive knee flexion substantially increases the energy requirements
of walking and, if not corrected, can lead to chronic knee pain and
joint degeneration. |
Lower extremity model animated with gait
kinematics data of an individual with crouch gait. |
We have used models of the lower extremity in conjunction with joint angles
measured during gait analysis to estimate the lengths and velocities of
the hamstrings during normal and crouch gait. The results of these studies
have suggest that many individuals with crouch gait do not walk with "short"
hamstrings; in such cases, factors other than the hamstrings may be contributing
to knee flexion. We also are creating dynamic simulations to evaluate the
causes of crouch gait in individual subjects. These clinically-motivated
studies are enabled by several advanced modeling techniques. To represent
the geometry of children with cerebral palsy we have developed MRI-based
models of the musculoskeletal system and models that characterize common
bone deformities.
Arnold, Liu, Schwartz, Ounpuu, Delp. "The
role of estimating muscle-tendon lengths and velocities of the hamstrings
in the evaluation and treatment of crouch gait." Gait and Posture,
2006. (Download PDF)
Arnold, Liu, Schwartz, Ounpuu, Dias, Delp.
"Do the hamstrings operate at increased muscle–tendon lengths
and velocities after surgical lengthening?" Journal of Biomechanics,
2006. (Download PDF)
Arnold, Anderson, Pandy, and Delp. "Muscular contributions to hip and knee extension during the single limb stance phase of normal gait: a framework for investigating the causes of crouch gait." Journal of Biomechanics, 2005. (Download PDF)
Arnold, Blemker, and Delp. "Evaluation
of a deformable musculoskeletal model for estimating muscle-tendon lengths during crouch gait." Annals of Biomedical Engineeering,
2001. (Download PDF)
Delp, Arnold, Piazza. "Graphics-based
modeling and analysis of gait abnormalities." Biomedical Materials
and Engineering, vol. 8, pp. 227-240,1998. (Download
PDF)
Delp, Arnold, Speers, Moore. "Hamstrings and
psoas lengths during normal and crouch gait: implications for muscle-tendon
surgery." Journal of Orthopaedic Research, 1996. (Download
PDF) |
