Locomotion on Land Flashcards
Stability on land
For a land animal to be stable MW must be greater than FH
Explain this..
(wide bodied animals are more stable but have limited mobility because they cannot turn easyily. Runners must lean into a turn to counteract centrifugal force)
MW must be greater than FH
M = mass (weight) w= 1/2 width of body
>
F = centrifugal force
(a force, arising from the body’s inertia, which appears to act on a body moving in a circular path and is directed away from the centre around which the body is moving)
H = Height
What is a Quadruped?
An animal which has four feet, especially an ungulate mammal.
What is a Biped?
an animal that uses two legs for walking
A. As animals become larger their mass increases as a cubic function
X3=
B. However the strength of bones increasing according to cross-sectional area as a square function is…
(An animal that is 10x the length does not weigh 10x more, its actually x1000 more)
As an animal increases in length 10 fold, the strength of its bones is going to increase x100 (diametre one way vs diametre the other)
A. Length x width x height = X3
B. Twice the size
Types of locomotion:
- Ambulatory - (Ambush of zombies)
- Saltatorial - (Saltitorial conjunction)
- Cursorial - (Specialised Runners)
- Fossorial - (Fossil/Archeologist)
- Scansorial - (Aerial)
- Natatorial
- Graviportal (Gravity)
- Walkers
- Jumpers (Frogs)
- Specialised runners (Antelopes, horses, osterich)
- Digging and burrowing (Moles/Badgers)
- Adapted for climbing (Monkeys)
- Swimming (Seals/whales)
- Very large species (extreme size = dinosaurs/elephants)
Specialisations for running
The limb can effectively be extended by…
…running on the toes
Specialisations for running
Plantigrade =
Digitigrade =
unguligrade
= Walking on the sole (bear)
= Walking on the toes (dogs)
=Walking on the hoof (ungulates)
What is the summation of independent velocities?
SoIV = Different sections working independently to create faster overall movements than if you simply made that one element twice as long.
By keeping a series of bones and working them indapendantly you end up with SoIV = much greater speed of movement out at the extremeties as apposed to just extending the length of a femur or similar.
What is gait?
A subjects manner of walking
What is the specialisation of a cheetah which allows it to reach extra distance on each stride?
- Flexion of the spine
- Rotation and cross-over of the legs
Elastic ligaments do what?
Dampen ground impacts and store energy for the next stride.
