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Coordinating Landings with Compliance
How does surface stiffness affect landing? Cane toads stick the landing across a wide range of surface stiffness, and they rely more on their elbow to land on rigid surfaces while their shoulder puts in more effort on compliant surfaces. Additionally, the overall energy required by the toads to slow themselves decreases on compliant surfaces - which explain why trampolines are more fun and easier to jump on while hopping on concrete is more of a workout. |
Above are examples of the same toad landing on a rigid surface (left) and the most compliant surface (right; 10 mm of displacement per body weight).
The top plots is the limb extension ratio (LER; in magenta) throughout landing, where a LER of 1 would be the arms fully stretched out and a value of 0 having the hands flexed up against the chest.
The middle plots show the magnitude of the ground reaction force (GRF; in blue) and the displacement of the platform (orange).
The bottom plots are the instantaneous joint powers for the wrist, elbow and shoulder joints.
The top plots is the limb extension ratio (LER; in magenta) throughout landing, where a LER of 1 would be the arms fully stretched out and a value of 0 having the hands flexed up against the chest.
The middle plots show the magnitude of the ground reaction force (GRF; in blue) and the displacement of the platform (orange).
The bottom plots are the instantaneous joint powers for the wrist, elbow and shoulder joints.
Next Step
After figuring out that cane toads use muscles in the shoulder joint to slow themselves down when landing on compliant surfaces I became interested in how cane toads may be modulating their muscle activity in preparation for and during landing. Click here to learn more about my second chapter which addressed this question.
After figuring out that cane toads use muscles in the shoulder joint to slow themselves down when landing on compliant surfaces I became interested in how cane toads may be modulating their muscle activity in preparation for and during landing. Click here to learn more about my second chapter which addressed this question.
