# Twente Lower Extremity Model v.2.1¶

The Twente lower extremity model version 2 (TLEM2) is a successor to the TLEM model. It contains 6 DOF and 169 muscles.

The model is based on published anatomical data produced from a cadaver study in the TLEMsafe EU project (see the study by Carbone et al. at the University of Twente, The Netherlands). The first implmentation of the musculoskeletal model was created by Vincenzo Carbone and René Fluit from the University of Twente 1.

After the TLEMsafe project the model was futher refined in the Life Long Joints project where its anatomical fidelity and joint force prediction accuracy were improved by De Pieri et al. 2, resulting the version 2.1 which was integrated here in the AMMR.

Key feature of this TLEM 2.1 model in the AMMR is:

• Unlike the old TLEM model, the dataset consisted of muscle attachment data & bone surface scans from the same subject. This makes TLEM2 the more anatomically consistent model. Bone contact at joints such as the knee thus consists of naturally congruent surfaces, making it easier to implement Force Dependent Kinematics on joint moments (see tutorial)

• Updated the wrapping surfaces for several muscles. These changes were engineered to result in realistic muscle coordination and hip contact forces as documented in the publication by De Pieri et al. 2

New wrapping surfaces for (clockwise) Gluteus maximus, Ilio-Psoas, Gluteus medius & minimus, Hamstrings & Gastrocnemius (version 1.2). All figures are from the publication by De Pieri et al. 2

## Example Configuration¶

Short example of how to configure the model with the TLEM model, Hill type muscle model and only one leg:

#define BM_LEG_MODEL _LEG_MODEL_TLEM2_
#define BM_LEG_RIGHT ON
#define BM_LEG_LEFT OFF
#define BM_LEG_MUSCLE _MUSCLES_3E_HILL_


The Leg configuration parameters for a full list of configuration parameters.

## Resources¶

More details on the TLEM2 model can be found online:

## References¶

If you need to cite the model use the following references:

Other usefull papers using or related to the TLEM2 model are:

1

Carbone,V., Fluit,R., Pellikaan,P., van der Krogt,MM., Jansen,D., Damsgaard,M., Vigneron,L.,Feilkas,T., Koopman,HF., Verdonschot,N., “Tlem 2.0–A comprehensive musculoskeletal geometry dataset for subject-specific modeling of lower extremity”, J. Biomech.,48(5) (2015) 734-741.

2(1,2,3)

De Pieri,E., Lund,ME., Gopalakrishnan, A, Rasmussen, KP., Lunn, DE., Ferguson, SJ. “Refining muscle geometry and wrapping in the TLEM 2 model for improved hip contact force prediction” PloS One 13 (2018) ( link )