Getting Started: Defining your Research Goals for the Model
- What results do I need to answer my research question?
- What elements of a model might these results be sensitive to?
- In what ranges will my study be conducted and in what ranges has the model been validated? If a model is not valid in the ranges of your study, how can you extend those ranges and re-validate the model?
- What structures or systems are modeled?
- Is it a kinematic model or full dynamic model? Is it 3D?
- Is it a model of a new structure or structures? Does it build on an existing model? What models can it be compared to?
- What experimental data was used to build and test the model? If human or animal subjects were used, how many and what type of subjects (age, size, etc.)?
- What platform(s) is the model implemented in?
- Can the model be scaled or otherwise customized?
- Has the model been published or otherwise peer reviewed?
- Do other studies use/cite the model?
- Has the author of the model changed or updated the model since the original publication? Do I have and understand the most recent version?
- Bone Geometry
- What bony segments are included in the model?
- What experimental or literature data was used to define bone geometry?
- Joint Geometry
- How many joints and how many degrees of freedom?
- How are the joints modeled? Types? Joint axis definitions? Coordinates? Neutral positions?
- Is there coupling of joint motions?
- What is the joint range of motion? Are there other limits or other constraints?
- What experimental or literature data was used to define the joint geometry?
- Muscle Geometry
- How many muscles are included in the model?
- How are muscle attachment points defined?
- Are broad muscles represented by multiple segments?
- Does the model have wrapping surfaces or via points? What features do they represent?
- What experimental or literature data was used to define the muscle geometry?
- Other Structures
- Does the model include ligaments?
- Does the model include prosthetics, orthotics, or other devices?
- Does the model include segment inertial parameters?
- What experimental or literature data was used to define the intertial parameters?
- Are there segments without intertial parameters? (This is a challenge for creating forward simulations with the model.)
Actuators and Other Force-Generating Elements
- Does the model include muscle actuators?
- What type of model is used for muscle-tendon force generation?
- How is muscle architecture modeled? What parameters define muscle architecture?
- How is activation-contraction dynamics of muscles modeled? What parameters define?
- Was there any fine-tuning/adjustment of muscle model parameters?
- Does the model have any other actuators (e.g. powered prosthetics, reserve actuators at the joints)?
- Does the model have any other passive force-generating elements (e.g. damping at joint extremes)?
Controllers and Sensors
- Does the model have any custom controllers?
- Does the model have any custom sensors?
- Is a model of foot/floor contact included?
- Does the model include any other representations of of contact with external objects?
- Were model moment arms compared to experimental data?
- Were maximum active joint moments compared to experimental data?
- Were passive joint moments compared to experimental data?
- Was a sensitivity analysis performed for any of the parameters of the model?
- Has the model been used to generate simulations?
- How much time is required to generate simulations of standard motions (e.g. walking, reaching)?
- How do the results compare to previously published data?
- For example, if a lower extremity model, does the model accurately predict knee forces from the grand challenge data set (https://simtk.org/home/kneeloads)?