CT scan of Nile crocodile lungs (NNC6)

This file includes the DICOM files for Crocodylus niloticus specimen number NNC6 (0.8kg). The lungs of NNC6 were inflated and scanned in a medical grade CT unit at the Royal Veterinary College, London at 90 kVp and 133MA with a slice thickness of 0.75 mm The lungs were excised and soaked in an iodine potassium iodide (I2KI) solution at concentrations varying from 2.25%-3.75% (following the methods of Jeffery et al., 2001; reference available in the manuscript) prior to scanning

Micro CT scan of Nile crocodile lung (NNC9)

This file includes the DICOM files for the lungs of Crocodylus niloticus specimen number NNC9 (0.58kg). The lungs were excised and soaked in an iodine potassium iodide (I2KI) solution at concentrations varying from 2.25%-3.75% (following the methods of Jeffery et al., 2001; reference available in the manuscript) prior to scanning. The lungs of NNC9 were scanned in a micro CT unit at the University of Cambridge with a slice width of 0.0816 mm

Video_2_A Dynamic Simulation of Musculoskeletal Function in the Mouse Hindlimb During Trotting Locomotion.AVI

<p>Mice are often used as animal models of various human neuromuscular diseases, and analysis of these models often requires detailed gait analysis. However, little is known of the dynamics of the mouse musculoskeletal system during locomotion. In this study, we used computer optimization procedures to create a simulation of trotting in a mouse, using a previously developed mouse hindlimb musculoskeletal model in conjunction with new experimental data, allowing muscle forces, activation patterns, and levels of mechanical work to be estimated. Analyzing musculotendon unit (MTU) mechanical work throughout the stride allowed a deeper understanding of their respective functions, with the rectus femoris MTU dominating the generation of positive and negative mechanical work during the swing and stance phases. This analysis also tested previous functional inferences of the mouse hindlimb made from anatomical data alone, such as the existence of a proximo-distal gradient of muscle function, thought to reflect adaptations for energy-efficient locomotion. The results do not strongly support the presence of this gradient within the mouse musculoskeletal system, particularly given relatively high negative net work output from the ankle plantarflexor MTUs, although more detailed simulations could test this further. This modeling analysis lays a foundation for future studies of the control of vertebrate movement through the development of neuromechanical simulations.</p

Image_3_A Dynamic Simulation of Musculoskeletal Function in the Mouse Hindlimb During Trotting Locomotion.TIF

<p>Mice are often used as animal models of various human neuromuscular diseases, and analysis of these models often requires detailed gait analysis. However, little is known of the dynamics of the mouse musculoskeletal system during locomotion. In this study, we used computer optimization procedures to create a simulation of trotting in a mouse, using a previously developed mouse hindlimb musculoskeletal model in conjunction with new experimental data, allowing muscle forces, activation patterns, and levels of mechanical work to be estimated. Analyzing musculotendon unit (MTU) mechanical work throughout the stride allowed a deeper understanding of their respective functions, with the rectus femoris MTU dominating the generation of positive and negative mechanical work during the swing and stance phases. This analysis also tested previous functional inferences of the mouse hindlimb made from anatomical data alone, such as the existence of a proximo-distal gradient of muscle function, thought to reflect adaptations for energy-efficient locomotion. The results do not strongly support the presence of this gradient within the mouse musculoskeletal system, particularly given relatively high negative net work output from the ankle plantarflexor MTUs, although more detailed simulations could test this further. This modeling analysis lays a foundation for future studies of the control of vertebrate movement through the development of neuromechanical simulations.</p

Table_1_A Dynamic Simulation of Musculoskeletal Function in the Mouse Hindlimb During Trotting Locomotion.DOCX

<p>Mice are often used as animal models of various human neuromuscular diseases, and analysis of these models often requires detailed gait analysis. However, little is known of the dynamics of the mouse musculoskeletal system during locomotion. In this study, we used computer optimization procedures to create a simulation of trotting in a mouse, using a previously developed mouse hindlimb musculoskeletal model in conjunction with new experimental data, allowing muscle forces, activation patterns, and levels of mechanical work to be estimated. Analyzing musculotendon unit (MTU) mechanical work throughout the stride allowed a deeper understanding of their respective functions, with the rectus femoris MTU dominating the generation of positive and negative mechanical work during the swing and stance phases. This analysis also tested previous functional inferences of the mouse hindlimb made from anatomical data alone, such as the existence of a proximo-distal gradient of muscle function, thought to reflect adaptations for energy-efficient locomotion. The results do not strongly support the presence of this gradient within the mouse musculoskeletal system, particularly given relatively high negative net work output from the ankle plantarflexor MTUs, although more detailed simulations could test this further. This modeling analysis lays a foundation for future studies of the control of vertebrate movement through the development of neuromechanical simulations.</p

Image_1_A Dynamic Simulation of Musculoskeletal Function in the Mouse Hindlimb During Trotting Locomotion.TIF

<p>Mice are often used as animal models of various human neuromuscular diseases, and analysis of these models often requires detailed gait analysis. However, little is known of the dynamics of the mouse musculoskeletal system during locomotion. In this study, we used computer optimization procedures to create a simulation of trotting in a mouse, using a previously developed mouse hindlimb musculoskeletal model in conjunction with new experimental data, allowing muscle forces, activation patterns, and levels of mechanical work to be estimated. Analyzing musculotendon unit (MTU) mechanical work throughout the stride allowed a deeper understanding of their respective functions, with the rectus femoris MTU dominating the generation of positive and negative mechanical work during the swing and stance phases. This analysis also tested previous functional inferences of the mouse hindlimb made from anatomical data alone, such as the existence of a proximo-distal gradient of muscle function, thought to reflect adaptations for energy-efficient locomotion. The results do not strongly support the presence of this gradient within the mouse musculoskeletal system, particularly given relatively high negative net work output from the ankle plantarflexor MTUs, although more detailed simulations could test this further. This modeling analysis lays a foundation for future studies of the control of vertebrate movement through the development of neuromechanical simulations.</p

Mesquite Data

Mesquite (Nexus) data files for phylogenetic analysis of evolutionary patterns in body dimensions. http://mesquiteproject.org/mesquite/mesquite.html for information on usage and free software download

Mass Segment objs

.obj graphics files (data)- 3D body segment dimensions of archosaur

CoMEstimationInstructions

Instructions for using the code and data her

The result of material properties, frictional coefficient and damping coefficient sensitivity analyses of the foot finite element model.

a<p>RMSE  =  root mean square error, rRMSE  =  relative root mean square error, F_x  =  horizontal component of ground reaction force, F_y  =  vertical component of ground reaction force, CoP  =  displacement of center of pressure, FRA  =  foot rotation angle, PRA  =  phalanx rotation angle, HP  =  plantar pressure in the heel medial region, MP  =  plantar pressure in the 1^st metatarsal region. The first three sets of parameters are material properties, and the final set involves altering the frictional coefficient from 0.6.</p