Studying how changing a human hip muscle attachment point location can change loads in the hip
Client:
UCLA's D Geffen School of Medicine
Business:
A leading research school
Challenge:
Abnormal walking patterns or gait caused by skeletal deformities and cerebral palsy are often treated by surgical intervention. By changing the location where a muscle attaches to the bone, the surgeon changes the way a muscle works across the joint, in turn changing the patient's gait or joint function. Since it is a 3-dimensional system with many muscles spanning the joint, it is difficult to understand the mechanical dynamics and predict an attachment point that will benefit a patient, leading to multiple revisions. Revision surgeries are difficult and painful, especially for children, which make up a plurality of these patients.
Solution:
A LifeMOD™ 3-D musculoskeletal model of the pelvis and left leg were created using data from the internal anthropometric library. The pelvis was anchored to ground. The lower leg was moved through a specific flexion path to train the muscles in the model to respond to the motion using LifeMOD’s inverse-dynamics training method. Muscle forces in the hip were recorded and displayed. The proximal attachment of the anterior gluteus medius muscle group was reposition 2 mm anterior. LifeMOD was then used to optimize the new muscular configuration to have the model attempt to reproduce the same motion now with the new hip muscle configuration. Changes in the modified muscle were observed as well as the surrounding muscles to understand the redistribution of the muscle loads to compensate for the changes in the system.
Value:
This model greatly increases the understanding of the hip muscular complex for students, researchers and physicians. Many “what if” tests may be performed on the model, accelerating the intuition of the surgeon or educator.
See newsletter for more details.
See newsletter for more details.