Bodies in Motion

This project is an art-science fusion project which is  a part of the Marie Christine Kohler Fellowship 2022-23 cohort. Specifically our project combines sensor technology with the medium of modern dance to encourage the audience to be more aware about their health and fitness. Sensors are now incredibly common with 216 million people worldwide currently owning a smart watch. These watches have become increasingly versatile and are able to capture health related information such as heart rate which combined with age, sex, weight and other personal information can give you a cardio fitness score. Sensors are capable of a lot more such as quantifying the biomechanical characteristics of a body and using this information to improve athletic performance,  build prosthetics and even analyze ergonomic performance. This performance uses the Xsens system containing sensors worn by a dancer to extract data during a performance to create an animated avatar and simultaneously measure variables such as  center of mass, velocity and joint angles among other information. In this performance the audience can directly see how different biomechanical data, measured by sensors, can be used to the dancer and choreography to understand how their bodies perform the choreographed movements. The centre of mass information captured by the sensors is transformed via code to culminate into a visual representation as seen in the LED lights during the performance. The visual representation of movement is intended to help the audience understand data generated by the sensors. 

Watch the Performance: 

While watching the performance, we invite audience members to open their minds to a multitude of possibilities for the meanings for the performance. There is not necessarily one ‘correct’ interpretation of what this dance means! So, we encourage you to think about your own interpretation of the dance (what is the main theme, what is the story line, what concepts do you see repeated, etc.). We also hope you will participate in the interactive portion of the performance and interpret the connection between the dancer’s movements and the light. 

Methods:

Sensor suit: Xsens System developed by Movella Inc. 

Software: Xsens motion capture software 

LED lights: Govee RGBIC LED strip lights (Amazon)

Software used to code lights: Python-based robotic operating system (ROS)

Dance: Modern dance

The Science Behind the Project: 

This project uses the Xsens System. This system uses a motion capture suit including  Inertial Measurement Unit (IMU) sensors along with proprietary software that captures different variables (e.g., center of mass and joint angles) to output data relating to performance, wellness, and injury.  This data can then be used to assess individuals with injury or disabilities along with the performance of prosthetics to ensure efficacy. However, the system is not limited to just that but has versatile uses such as assessing athletic performance and quantifying body movement to determine optimal performance. In fact, the Xsens system was used by Hokusho University to evaluate performance metrics of Olympic gold medallist Ryoyu Kobayashi which helped him win a gold medal in the 2020 Olympics.

The software can be divided into two versions, MVN animate to visualise movement along with MVN Analyze, which is used in research settings to analyze data output by the sensors. There are up to 17 wireless IMU sensors which may be used at a time and contain a gyroscope (a device used to measure and maintain orientation and angular velocity) along with an accelerometer (a device that measures force caused by a vibration thereby measuring acceleration of motion). The gyroscope gives us an idea of the rate at which something moves via rotation or revolution with respect to its center of rotation (axis). And the accelerometer tells us the change in velocity (speed in a given direction) of the person. The system can further give us information about joint angles during movement along with movement of the body in space. This biomechanical data can be used to test prosthetic devices and compare against a human leg to design physiologically relevant prosthetics. 

The performance captures all this data and more but we specifically use the centre of mass data for the visual representation via light as it is much easier to discern with the human eye. We chose Govee LED lights that have bluetooth functionality to connect via a Raspberry Pi (essentially a mini computer) to the system. Centre of mass is the point about which an object will be balanced if you try to rest it on your fingertip and this can change in any object that can move such as the human body. So the point at which the weighted relative position of the distributed mass is equal to zero is the centre of mass. The dancer generates data about their centre of mass  as it moves in space and the change in centre of mass is assigned colours which represent movement in specific directions. For example, if the dancer moves to their right with respect to their current position then the lights would skew red and moving in the opposite direction would change lights to blue with the centre being represented by green. The change in centre of mass as the position of the dancer moves up and down is also represented via brightness of the lights. During the performance, the audience is encouraged to analyze the connection between change in centre of mass to colour of light and brightness. 

Simultaneously, the dancer’s movement can be viewed in real-time as an avatar on screen due to MVN animate technology as variables change. Altogether, this collaboration between the sciences and arts is meant to encourage thinking about intentional movement and how fitness is essential for the human body to function optimally. 

The Art Behind the Project: 

The choreography is created by Lauren Gerlowski (Kohler Fellow, PhD Student, dance artist) and performed by Lauren Gerlowski and Lucy Pierson. This dance was initially choreographed as a quartet at Point Park University, where Lucy was an original cast member! Lauren and Lucy are thrilled to premiere this work as a duet for the Illuminating Connections performance. 

This dance is a modern dance performance. Through this project we hope people can learn about the different pathways of movement from watching the sensor technology on bodies. Much of modern dance is based on the natural state of the human body. All modern dance does not rely on forced positions but instead relies on creating energy to move the body through space in interesting ways. In using this form, people may be able to relate to dancers more than other forms because it is rooted in natural body shapes and ways of moving through movement with momentum. 

While modern dance is part of the larger institution of Western concert dance, which has many roots in colonialism and propaganda for the West, modern dance as a dance form was actually created to push back against the rigidity of classic Western dance styles (such as ballet) and create an opportunity for women and people of color to showcase their choreography. We recognize that modern dance still has issues of colonialism (particularly in ways that bodies have individually been colonized through codification of dance forms) but we want to focus on the ways that many modern dance leaders (e.g. Trisha Brown, Alvin Ailey, José Limon) have shaped modern dance to hold a lot of emancipatory energy to create connections. In this way we are using the inspiration from modern dance pioneers to make connections between art and science. 

A major reason we are choosing modern dance performance is because Lauren is classically trained in modern dance performance and choreography. This project is a big undertaking and we wanted to simplify as much of the production-side as possible. This includes leaning into our current skill sets. While it would be interesting to do this performance with non-Western dance forms, we recognize the limits of our capacity.