class: center, middle, inverse, title-slide .title[ # Lecture 3 ] .subtitle[ ## Terrestrial Locomotion II ] .author[ ### Dr. Christopher Kenaley ] .institute[ ### Boston College ] .date[ ### 2024/1/23 ] --- class: inverse, top # Terrestrial locomotion ``` ## Warning: package 'ggplot2' was built under R version 4.3.1 ``` ``` ## Warning: package 'dplyr' was built under R version 4.3.1 ``` ``` ## Warning: package 'stringr' was built under R version 4.3.1 ``` <!-- Add icon library --> <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/5.14.0/css/all.min.css"> .pull-left[ Today we'll .... - Consider other terrestrial gaits (jumping, running) - Flow of energy in terrestrial gaits - Postural considerations - Some work on MP1 ] .pull-right[  ] --- class: top # Some administrata .pull-left[ - Link to discussion: https://topicsinbiomechanics.slack.com/ - Post to discussion board by EOD today ] --- class: top # Jumping .pull-left[ - Animals move by exerting forces on a medium or substrate (eg., ground, water, plants, air) `$$\Sigma F=m\cdot a$$` Where on the body do we measure acceleration? - if we consider the body as an infinite number of particles `$$x_{com}=\frac{1}{m}\int_{0}^{m}xdm$$` `$$y_{com}=\frac{1}{m}\int_{0}^{m}ydm$$` ] .pull-right[  .footnote[ **Upshot:** COM is a function of shape ] ] --- class: top # Jumping .pull-left[ - Animals move by exerting forces on a medium or substrate (eg., ground, water, plants, air) `$$\Sigma F=m\cdot a$$` Where on the body do we measure acceleration? - if we consider the body as an infinite number of particles `$$x_{com}=\frac{1}{m}\int_{0}^{m}xdm$$` `$$y_{com}=\frac{1}{m}\int_{0}^{m}ydm$$` ] .pull-right[   .footnote[ **Upshot:** COM is a function of shape ] ] --- class: top # What happens in transition? .center[ <img src="img/froudegait.jpg" width="550" /> ] --- class: top # What happens in transition? .pull-left[ .center[ <img src="img/pend.png" width="450" /> ] ] .pull-right[ .center[ <img src="img/springmass.jpg" width="450" /> ] ] --- class: top # Running mechanics and dynamics .center[  ] --- class: top # Running mechanics and dynamics .center[  ] --- class: top # Running mechanics and dynamics .righ-column[ .right[ <img src="img/energycomp.png" width="500" /> ] ] --- class: top # Running mechanics and dynamics .left-column[ .center[ `$$KE=\frac{1}{2}mv^2$$` `$$PE=mgh$$` `$$U=\frac{1}{2}kx^2$$` ] ] .righ-column[ .right[ <img src="img/energycomp.png" width="500" /> ] ] --- class: top # Running mechanics and dynamics Energy transfer  --- class: top # Energy transfer and damping .center[ <img src="img/musclesprings.jpg" width="500" /> ] .pull-left[  ] .pull-right[ .footnote[Tendons are viscoelastic] <img src="https://www.physio-pedia.com/images/thumb/d/db/Hysteresis_curve_intechopen.jpeg/357px-Hysteresis_curve_intechopen.jpeg" width="225" /> ] --- class: top # Energy transfer and posture .pull-left[ .center[ [barefoot running](https://www.youtube.com/watch?v=r6YhVN_YIUk) ] ] .pull-right[ <img src="https://www.physio-pedia.com/images/thumb/d/db/Hysteresis_curve_intechopen.jpeg/357px-Hysteresis_curve_intechopen.jpeg" width="300" /> **What's the problem here?** ] --- class: top # Energy transfer and posture .pull-left[ [shod running](https://www.youtube.com/watch?v=zavoQM3727s) ] .pull-right[ <img src="https://www.physio-pedia.com/images/thumb/d/db/Hysteresis_curve_intechopen.jpeg/357px-Hysteresis_curve_intechopen.jpeg" width="300" /> **How does this better facilitate energy transfer?** ] --- class: center, middle # Thanks! Slides created via the R package [**xaringan**](https://github.com/yihui/xaringan).