MSC Software's Adams used in Musculoskeletal Models that Simultaneously Predict Knee Loading and Muscle Forces during Movement

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MSC Software, a leading global provider of simulation software and services, announced today that its flagship product, Adams was integral to research in musculoskeletal biomechanics at the University of Missouri, Kansas City. Researchers are using Adams for simultaneous prediction of knee loading and muscle forces during human movement. The multibody modeling software simulates the articulations of cartilage covered bone, the forces of ligaments crossing the knee, as well as the dynamic motion and loading of knee menisci. The subject specific knee models are placed within body level musculoskeletal models that include prediction of muscle forces as well as contact between the foot and ground. Loading on knee structures, such as ligaments and cartilage, is then predicted during muscle force driven simulations of walking or other activities.

Knowledge of the mechanical loading on joint tissue benefits medical device design, injury prevention and orthopaedics. For example, a better understanding of the contact location and contact pressures of knee articular cartilage during walking or stair climbing could help guide the design of plastic and metal knee replacements. This knowledge could also guide physical therapy intervention strategies that modify the way a person walks to slow or prevent the progression of osteoarthritis by altering cartilage loading. Another application is that a better understanding of knee motion and forces could aid in the prevention of knee injury and guide orthopaedic repair. Predicting the relationship between muscle activations and bone motion could help prevent ligament damage and guide reconstruction surgeries such that the movement of the joint as well as the locations and magnitude of cartilage pressures are restored.

Geometries for the models are constructed from magnetic resonance images (MRI). These geometries include bone, cartilage, menisci, and ligament and muscle origin/insertions. Deformable contacts are defined in Adams between articulating cartilage surfaces of the knee as well as between the foot and ground. Multiple ligament bundles are defined for each ligament crossing the knee. The motion, ground reaction forces, and muscle activations of each subject are recorded in a gait lab and used for body level movement simulations that include the anatomical knee models. The menisci are represented in the multibody framework by dividing the menisci geometries into multiple rigid bodies. Adams field elements connect the rigid bodies allowing the menisci to deform and move on the tibia plateau.

Dr. Trent Guess, Mechanical Engineer and Associate Professor of Physical Therapy and Orthopaedic Surgery at the University of Missouri, Kansas, reiterates the usefulness of Adams in his research. "The University of Missouri is using Adams software in musculoskeletal and orthopaedic biomechanics research. The multibody simulation software is used to create subject specific computational knee models that include ligaments and contact between knee geometries derived from medical images.  The knee models are incorporated in muscle driven body level simulations based on measured body kinematics where the force on knee structures is predicted during movement," he said.