Preview

Bubbles Like Sex

Better Essays
Open Document
Open Document
1424 Words
Grammar
Grammar
Plagiarism
Plagiarism
Writing
Writing
Score
Score
Bubbles Like Sex
Walking involves a cyclic exchange of gravitational potential energy and kinetic energy of the center of mass. Our goal was to understand how the limbs of walking quadrupeds coordinate the vertical movements of the fore and hind quarters to produce these inverted pendulum-like movements. We collected kinematic and ground reaction force data from dogs walking over a range of speeds. We found that the fore and hind quarters of dogs behaved like two independent bipeds, each vaulting up and over its respective support limb. The center of mass moved up and down twice per stride, like a single walking biped, and up to 70% of the mechanical energy required to lift and accelerate the center of mass was recovered via the inverted pendulum mechanism. To understand how the limbs produce these center of mass movements, we created a simple model of two independent pendulums representing the movements of the fore and hind quarters. The model predicted that the fore and hind quarter movements would completely offset each other if the fore limb lagged the hind limb by 25% of the stride time and body mass was distributed equally between the fore and hind quarters. The primary reason that dogs did not walk with a flat trajectory of the center of mass was that each fore limb lagged its ipsilateral hind limb by only 15% of the stride time and thereby produced time periods when the fore and hind quarters moved up or down simultaneously. The secondary reason was that the fore limbs supported 63% of body mass. Consistent with these experimental results, the two-pendulum model predicts that the center of mass will undergo two fluctuations per stride cycle if limb phase is less than 25% and/or if the total mass is not distributed evenly between the fore or hind quarters.

KEY WORDS locomotion physiology mechanical energy work ground force gait Canis familiaris
Previous Section
Next Section
Introduction

Legged animals generally get from place to place using a walking gait. Gaits

You May Also Find These Documents Helpful

  • Good Essays

    Uakari Tibia

    • 987 Words
    • 4 Pages

    After determining the dental formula, the student had to measure the tibia & fibula and the radius & ulna of both specimen’s A & B to determine their type of locomotion that they used to get around. II.…

    • 987 Words
    • 4 Pages
    Good Essays
  • Good Essays

    It is very important to their survival that they can run on all four legs because…

    • 802 Words
    • 4 Pages
    Good Essays
  • Satisfactory Essays

    Gait is rhythmic and coordinated with purposeful movements. Full strength present. No visible deformities. Muscles are bilaterally equivalent in strength. No visible deformities.…

    • 1482 Words
    • 13 Pages
    Satisfactory Essays
  • Good Essays

    Non Amputees Lab Report

    • 1026 Words
    • 5 Pages

    2; Slope +9). A similar trend was observed for downhill walking: the locked ankle resulted in reduced negative peak power in early to mid-stance (Fig. 2; Slope -9). This gives us reason to believe that the locked ankle is not able to absorb as much energy upon weight acceptance when walking downhill, and it was not able to provide as much power at push-off when walking uphill. The locked ankle condition also lead to a reduced amount of negative work when walking downhill and a reduced amount of positive work when walking uphill, as compared to the control…

    • 1026 Words
    • 5 Pages
    Good Essays
  • Good Essays

    The Taung Child

    • 812 Words
    • 4 Pages

    The Taung child was found with the whole face and lower jaw complete with many teeth (Figure 2). As well, most of the cranium portion was intact with a natural endocast of the braincase (Dart, 1925). Only in very rare cases does a fossil have an endocast. Dart focused on the features of the brain because he saw signs of cerebral advancement towards humans. The foramen magnum was positioned upright from the spinal cord which is present in bipedal locomotion in an upright position. When the foramen magnum is positioned directly above the neck, it allows carriage of the head and the ability to look downwards. Four-legged creatures walk with their eyes facing forward, thus the foramen magnum is positioned at the rear of the skull. The bipedal motion…

    • 812 Words
    • 4 Pages
    Good Essays
  • Good Essays

    Muscle Change in People

    • 390 Words
    • 2 Pages

    Which lower extremity muscles are utilized during standing and walking? They are your Quadriceps they are the biggest muscles by far they are at the front of the thighs. They raise the thigh and leg. Then there are the Hamstrings these form the back of the thighs and move the leg backward. The Buttocks powerful and bulky complete the backward movement of the step. Stomach muscles contract with each step forward. The Calf is smaller but is the most heavily used muscle when you take a step. There are also secondary that are used and they are: The Pelvis’s Stabilizing these form a muscular crown around the pelvis. Symmetrical Tibialis Anterior muscles are in the front of the calf muscle raises the foot so it doesn’t scrap the ground as you take a stride.…

    • 390 Words
    • 2 Pages
    Good Essays
  • Satisfactory Essays

    Like Water Like Chocolate

    • 749 Words
    • 2 Pages

    In the [pic]book Like Water for Chocolate, Tita has to choose between passion or stability. There is no man in between with whom she can spend her life. Though Pedro is not very caring and supportive, he and Tita have an enormous [pic]passion for one another. John does all he can to make Tita happy and cares about her a lot, but this is not enough to overcome their lack of [pic]passion.…

    • 749 Words
    • 2 Pages
    Satisfactory Essays
  • Good Essays

    Koko

    • 702 Words
    • 3 Pages

    In order to be able to walk or run on two feet many evolutionary changes had to occur, early humans had to develop arches in their feet, curved spines, specialized hips, and specialized knees. The muscle structure of the early human body also had to…

    • 702 Words
    • 3 Pages
    Good Essays
  • Good Essays

    Can stand up with some needed support when doing this they can bounce up and down this uses all their leg muscle strength.…

    • 540 Words
    • 3 Pages
    Good Essays
  • Good Essays

    Bipedalism Research Paper

    • 1311 Words
    • 6 Pages

    It’s probably harder and we cannot run fast doing so just because we have evolved out of being quadrupeds. But looking at the fastest animals in the world, most of the fastest animals run on four legs. I’m not saying that we should run on all fours but that speed was no longer a necessity in our survival. There are many disadvantages of being biped as well as advantages. I have noticed that almost all of these disadvantages are directly correlated with the advantages. Basically, everything in our evolution process was a system of trade-offs. A perfect example of this is shown here, “Still other advantages of Bipedalism would have enhanced survivability. With their heads up well above the ground, bipeds are able to spot predators before they get too close for safety.”, which can be compared to, “ Bipedalism makes an animal more visible to predators, and exposes its ‘soft underbelly’.” See how it’s all a system of trade-offs? I could show many more examples, but you get the point. More disadvantages of Bipedalism are limiting the ability to run faster or change direction quicker when running. “Quadrupedal baboons and chimpanzees are 30 – 34 percent faster than…

    • 1311 Words
    • 6 Pages
    Good Essays
  • Good Essays

    Ch 10 Muscle Tissue

    • 1226 Words
    • 5 Pages

    Producing body movements total body movements (ex- walking and running) and localized movements (ex- grasping a pencil, keyboarding, or raising your hand), all rely on the integrated functioning of skeletal muscles, bones, & joints.…

    • 1226 Words
    • 5 Pages
    Good Essays
  • Satisfactory Essays

    What Is Kinestecia?

    • 115 Words
    • 1 Page

    Kinestecia indicates the position of the limbs, their movements and the posture of the body as a whole, using a series of impulses by which it is possible to coordinate all parts of the body in a series of complex acts; Such as the synchronized coordination of the body in a normal gait. The control of an action requires the knowledge of the movement and the position of the different parts of the body, and even when all the senses contribute to it, the initial information is given by the muscular sense or Kinestecia, whose special feature is that the stimulus comes Of the same organism, unlike the others, whose stimuli come from the…

    • 115 Words
    • 1 Page
    Satisfactory Essays
  • Good Essays

    Bipedalism Research Paper

    • 596 Words
    • 3 Pages

    There are many milestones in human history that makes us who we are today, however bipedalism is the most important among all of those major milestones. Bipedalism allowed people to expand their brain function by utilizing different parts of their brain and to stand up and free their hands for other uses. Bipedalism…

    • 596 Words
    • 3 Pages
    Good Essays
  • Good Essays

    Children follow a sequence of development. Gross and fine motor skills are the starting points and lead into other areas. Locomotion uses the large movements and the ability to move around under ones “own steam”. This begins with a baby learning to first crawl or bum shuffle, and then develop the ability to…

    • 585 Words
    • 3 Pages
    Good Essays
  • Powerful Essays

    legs, where if it were walking and one saw it from a profile perspective it would appear to…

    • 1400 Words
    • 6 Pages
    Powerful Essays