Physiological loads for mechanical testing of products

AnyBody models can be used to obtain realistic physiological load cases for testing implants. The data can be used in mechanical test setups or as input to a finite element simulation. The models simulate activities of daily living, and more strenuous physical activities such as e.g. deep knee bends, stairclimbing, etc. The musculoskeletal models are fully parametric and can be scaled to become patient specific, both in terms of specific bone shapes, body mass and strength. The predicted loads reflect the forces acting inside the body, accounting for externally applied loads and muscle contraction forces in combination. The loads include all individual forces acting on a bone. They can be exported to a finite element software to act as realistic time dependent loads. In addition to loads, motion is also part of the output. Finally, a knee simulator model is also available for easy testing of knee implants in a well-defined setup. It is a stand-alone demo model of a knee simulator device resembling the principles of the Kansas Knee simulator.

Examples:

  • Fixation plate test method development
  • Physiological dynamic load cases for finite element model
  • Preclinical testing of joint arthroplasty technologies capturing patient-specific and activity related variations
  • Physiological load cases for activities of daily living

Examples of input and output for a mechanical testing model:

Input:

  • Implants CAD files (STL)
  • Implant positioning data
  • Bone CAD files (STL)
  • Anthropometrics data
  • Motion data and ground reaction force

Output:

  • Implant motion
  • Implant contact forces (accounting for muscles)
  • Muscle and ligament forces
  • And much more

Contact us to learn more or to discuss how we could solve your problem

The steps to model this can be the following

  1. Reproduce the activity, e.g. walking, using your own data or an existing AnyBody model
  2. Select which bones to export the loads for
  3. Run the inverse dynamic model and export the XML file with the loads
  4. Use the FE interface tools for ANSYS or Abacus to convert the exported XML file to FE load cases

Models in AMMR

Selected papers

  • Liu T, Khalaf K, Adeeb S, El-Rich M (2019), “Effects of lumbo-pelvic rhythm on trunk muscle forces and disc loads during forward flexion: A combined musculoskeletal and finite element simulation study“, J. Biomech., vol. 82, pp. 116-123. [DOI]
  • Bitter T (2018), “A finite element approach for wear prediction at the taper junction in modular total hip arthroplasty“, Ph.D. Thesis, [Sl: sn].
  • Coombs DJ, Wykosky S, Bushelow M (2014), “Calcaneal Fixation Plate Test Method Development“, In: SIMULIA Community Conference, May 19-24, 2014, Providence, RI. [PDF]

More papers on orthopedics

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