Human Movement
Complexity Laboratory

What is movement complexity?
Before we answer that, what is biomechanics?

Biomechanics is the study of how forces affect how we move.

For example, when you stub your toe, there is a force from the impact of your toe on the table, and I am sure you know how that affects your movements. Biomechanics is a wide field that can examine forces on your teeth when you chew (dental biomechanics) or forces that cause injuries, like an ACL tear. Our lab focuses in a slightly different area of biomechanics.

When we move, we don’t move like robots.

Each movement is not exactly like the last one. We have variability in how we move. So much so that we are able to complete the same task using different muscles or even limbs. Think about writing your name with your non-dominant hand. You can still complete the task but it isn’t the same as doing it with your dominant hand.

How our research makes a difference

Movement complexity explores the nature of this variability, the patterns or fluctuations in our movements. In particular, our lab’s work is focused on walking and standing. Our goal is to understand the nature of this complexity and if it has been lost due to disease or injury, to introduce techniques to restore complexity.


Solving real-world problems

The variability of movement can be quantified using traditional tools like standard deviation and range, which gives us the amount of variability. We can also quantify patterns or fluctuations in our movements—the complexity of the movement. Are the patterns too predictable or too random? As we age, suffer from an injury or disease, we lose complexity in our movements.

The Human Movement Complexity Laboratory has studies in three major areas:

Quantifying Complexity

There are many tools that scientists use to quantify patterns and fluctuations in movement. Our work is focused on ensuring that these tools are valid and reliable. We have focused much of our work on the use of entropy. A recent review provides guidelines for consideration.

Coupling of Biorhythms

Different rhythms of the body are entrained, or coupled with one another. This is true for walking and breathing rhythms. In the past, we have studied how walking and breathing rhythm coupling is altered in persons with chronic obstructive pulmonary disease. Recently, we’ve broadened our focus and are exploring coupling of different biorhythms, coupling of signals captured through wearables, and the impact coupling may have on performance.

Aging and Resilience

We have always had an interest in functional outcomes as a person ages, especially with performing more than one task at a time. Or how disruptions to one’s walking or balance can alter their behavior. Our current work is focused on determining objective measures of resiliency, especially when confronted with a challenge to their movement.

Join Us


We are always looking for students to work with us in the lab. Interested students are encouraged to reach out to Dr. Yentes by sending her your resume/CV and a quick reason as to why you are interested in working in the lab. If you don’t have a resume, that is okay! Go ahead and send an email. Also, talk to the current students or former students to learn more about what it is like to work in the lab day-to-day and working with Dr. Yentes.


We are currently enrolling participants for the following studies.

Wearable bioelectronic device to detect changes in health status

Research Flyer

We are inviting people that may or may not have been diagnosed with chronic obstructive pulmonary disease (COPD) to participate in a research study to test the accuracy of a device.

You may be eligible to participate if you are:

  • Between the ages of 18-35 or 45-75 years old
  • You are not pregnant
  • You do not have a disease that would affect your breathing, heart rate, or walking

You will be asked to do:

  • Walk on a treadmill for 10 minutes, two different times, with rest in between
  • While walking you will wear an EKG, a newly invented device (like a band-aid), and markers that will capture your walking
  • The visit will take about 1 ½ hours
  • You will then wear the device home and mail it back after 24 hours

Interested in participating?

Leave us your name and email, and we’ll be in touch with more information.

Request info - Wearable Biotech

You may also reach out to the research team via email or phone.

Physical, physiological, and cognitive resiliency in older adults

We are inviting people between the ages of 45-85 years old to participate in a research study.

You may be eligible to participate if you are:

  • Right-handed
  • Are not claustrophobic
  • Do not have any metal in your body
  • Do not have a past brain injury

You will be asked to do:

  • Come to Texas A&M three times, each time will take about 1½ hours
  • During these visits, you may be asked to walk on a treadmill at various speeds or while having your blood drawn, and undergo an MRI while doing a memory test

Interested in participating?

Leave us your name and email, and we’ll be in touch with more information.

Request info - Physical, Physiological, and Cognitive Resiliency in Older Adults

You may also reach out to our research team via email or phone.