Tag Archives: biomechanics

Biomechanics to improve running performance
Gemma Malagón
2019, senior
Biomedical engineering
Tecnológico de Monterrey, Mexico

My Research Project

As a Fellow from the American Physiological Society (APS), Hearst Undergraduate Summer Research Fellowship, I was grateful to have had an opportunity to work under Dr. Arellano at the University of Houston at the Center for Neuromotor and Biomechanics Research.

My research this summer focused on the biomechanics of arm swing across different walking speeds and its effect on the metabolic cost. Our main objective was to better understand the passive and active contributions by examining the electromyographic (EMG) activity of the muscles involved in arm swing, with a special focus on understanding how changes in EMG amplitude in the upper limb varied across walking speed.

The data acquisition consisted of:

  1. Measurements of oxygen consumption and carbon dioxide production using indirect calorimetry, which is a process that measured the amount of heat that was released or absorbed during a chemical reaction;
  2. XYZ coordinates of joint positions, which has the objective to understand the kinematics of the body;
  3. Ground reaction forces; and
  4. Muscle activity of arm muscles of interest.

These measurements allowed us to compute and compare metabolic power, joint angles and mechanics and average muscle activity patterns when walking with and without arm swing.

Realities of Research

The research that I conducted was exciting and it was a wonderful experience working in the lab. In the beginning, I spent most of my time reading articles and doing research on my assigned project. I had an engineering background prior to my summer research, so one of the aims of my research project was to develop an efficient MATLAB code to process and analyze the EMG data collected on the studies.

I have learned to measure my progress due to the number of setbacks I had, which also helped me realize different paths which brought me closer to reaching my goal. I have learned more than I could ever hope and was fortunate to have had the opportunity to work—even for a little while—with some of the most talented and coolest people in the U.S.

Life as a Scientist

I made the decision to study biomedical engineering with a concentration in research driven by my desire to contribute to fundamental breakthroughs in medicine and become a better Mexican-researcher. This past summer, besides working on my own research, I’ve was involved in many lab projects, so I realized how amazing it is when you work with people who share the same passion as you. The truth is, having to work eight hours a day during the week, and some days even more, might be tiring! This was especially true when I would have to take the bus for two hours to get to the lab and two more hours to get back home. However, it was a unique experience that not everyone is willing to take advantage of. Participating in this program not only widened my research experience, but it has helped me on my path towards a master’s degree, which I plan to pursue after I graduate.


Christopher J. Arellano, Rodger Kram. Journal of Experimental Biology 2014 217: 2456-2461; doi: 10.1242/jeb.100420

Gemma Malagón is a senior majoring in biomedical engineering at the University of Tecnológico de Monterrey in Mexico. She is a Hearst Undergraduate Summer Research Fellow working in Dr. Arellano’s lab at the University of Houston, Health and Human Performance Department. Gemma’s fellowship is funded by the American Physiological Society and Hearst Foundations. After graduation, Gemma plans to pursue a master’s degree in clinical and sports engineering.


I would like to express my deepest appreciation to Hearst Foundations and the American Physiological Society (APS) for my research fellowship, and to Dr. Christopher J. Arellano, which the completion of my internship would not have been possible without his support and mentorship.

Do Birds Have a Butt-Brain?

This summer, I worked with Dr. Monica Daley in the Structure and Motion Lab located at the Royal Veterinary College just outside of London. I was working on characterizing the function of a specialized spinal structure in birds and some dinosaurs known as the lumbosacral organ (LSO). This organ is hypothesized to function as a balance sensor by responding to changes in cerebrospinal fluid (CSF) flow, or by sensing strain in associated spinal ligaments. At its core, the spine is just a bony tube that surrounds the spinal cord, with CSF sloshing around between these two structures. When a bird experiences a disruption in balance, the LSO may sense this and restore equilibrium with a fast spinal reflex, instead of sending the signal up to the brain. This work has implications in physiology, motor control, and evolutionary biology. Firstly, this is a novel balance sensation mechanism that will give us a better idea of how bipedal land birds can quickly overcome balance perturbations. Their motor control strategy may be applied in robotics to create more efficient and resilient locomotor systems. Additionally, the LSO is thought to be important in the transition from dinosaurs to birds. Better characterizing its structure and function may shed light on this key evolutionary event.


The everyday life of a scientist can vary widely across labs and research projects. One of the many reasons I love biomechanics as a field is the sheer scope of techniques that I get to employ on a daily basis. While the core of my project involves simulating CSF flow on a computer, often times I find myself breaking up my day with hands-on work as well. For instance, I might begin a simulation in the morning, but conduct a balance perturbation experiment on a live guineafowl while the program runs. The next day I could be dissecting and staining specimens, commuting into downtown London to run CT scans, 3D printing an experimental apparatus, or writing code for numerical models. I get to feel like a biologist, mathematician, and engineer all in the same day.


Research is not always as glamorous as it is portrayed in high school and college courses. I often found myself frustrated with code or software that wasn’t working as I thought it should be, for seemingly no reason. Additionally, the results that you generate are often very difficult to interpret at a first glance. A large amount of my time was spent troubleshooting, writing data analysis scripts, and consulting colleagues to help develop intuition for the physical phenomena I was observing in my fluid dynamics simulations. Despite these struggles, I always felt inspired and motivated by the fact that I was conducting research that had never been done before. The reason why conducting sound experiments and interpreting data is so challenging is because it is literally uncharted territory. The intellectual rewards of making progress in a research project are very satisfying and often outweigh the struggles of achieving them.


Ethan Wold is a rising junior at Brown University in Providence, RI where he is majoring in Biology and Geophysics. At school, he works with Dr. Thomas Roberts studying the biomechanics of muscle and connective tissue in a variety of organisms including frogs and turkeys. This summer, he worked in Dr. Monica Daley’s lab in the United Kingdom studying the biomechanics of balance sensation in bipedal land birds as an IOSP fellow. After graduating, Ethan plans to do some traveling and conservation work, and then pursue a PhD in biomechanics or bio-inspired engineering.