Department of Kinesiology

School of Health and Human Sciences

Labs: Virtual Environment for Assessment and Rehabilitation Laboratory

Check out Dr. Rhea’s recent TEDxGreensboro talk on the use of VR to address human health challenges!

Lab Location

247 Coleman Building

Lab Contact

Dr. Christopher K. Rheackrhea@uncg.edu

Overview

The focus of this lab is to understand the role of complex behavior in gait and postural control, and to develop novel rehabilitation interventions to enhance motor behavior—including the use of virtual reality and smartphone technology. As we navigate the environment, we must continually adapt our gait to avoid or accommodate obstacles such as stairs, other people or moving cars. After an injury, aging, or pathology, the ability to adapt gait to the environment is compromised, leading to an increased risk of falling and injury. To restore a patient’s ability to appropriately interact with the environment – termed functional mobility – a physical rehabilitation program is employed. Unfortunately, the decision of when functional mobility has been restored is largely subjective, making it difficult to know when a patient should be released to return to dynamic activity, such as sports or active duty. Releasing the patient prematurely could lead to an increased risk of further injury. To this end, the VEAR Lab objectively measures functional mobility using a dynamic systems approach, which is then merged with virtual reality and smartphone technology to enhance the assessment, tracking, and rehabilitation of a variety of clinical populations.

Media Highlighting our Research

Lines of Research

Metrics that quantify functional mobility – Our lab focuses on locomotor and posture dysfunction caused by a variety of etiologies. These dysfunctions may manifest in a number of different ways, requiring a multifaceted approach to understand the underlying dynamic changes. Locomotor and posture dysfunction can be caused by a variety of etiologies. Our lab does not focus on a particular clinical population, but strives to understand how functional mobility emerges and how a structural or neurological insult can disrupt functional mobility. These insults can change some components of a gait pattern, while leaving other components intact. Therefore, we use a variety of metrics to quantify the dynamics of a gait pattern to better characterize the impact of a structural or neurological insult on functional mobility.These metrics include:

  • Detrended fluctuation analysis (DFA) and multifractal detrended fluctuation analysis (MF-DFA) – measurements of long-range correlations over a variety of time scales
  • Sample entropy (SampEn) and multiscale entropy (MSE) – measurements of complexity
  • Recurrence quantification analysis (RQA) – Provides a measurement of many nonlinear characteristics of the time series, including determinism, entropy, and stability
  • We have adopted these metrics to understand locomotor dysfunction across a variety of clinical populations. This framework will allow rehabilitation programs to better design exercises suited to the particular needs of each population

VR and smartphone applications to restore functional mobility – Virtual reality (VR) is an intriguing medium to deliver physical rehabilitation due to its endless flexibility. Each clinical population presents a unique challenge to the rehabilitation team due to its specific structural or neurological decrements.A one-size fits all approach to rehabilitation is not optimal. Rather, a prescription of exercises designed to specifically target each patient’s particular deficit is more in-line with the optimal “personalized medicine” recommendations to optimize clinical practice. VR offers the ability to present locomotor training in a challenging, yet obtainable way that can be tailored to each locomotor deficit.While VR rehabilitation can enhance patient motivation due to the novelty of the training environment, we utilize VR as a medium to train the patient to regain the specific components of their gait pattern that have been altered due to an injury, aging or disease. For example, the timing between strides is altered following a rupture of the anterior cruciate ligament (ACL) in the knee.

We have created an avatar that is driven not by a computer program, but by the pre-recorded biomechanics of a healthy adult walking. When a patient comes into the laboratory, they are instrumented so they can see an avatar of themselves on the projection screen. Additionally, the “healthy” avatar is presented right next to the patient’s avatar. The patient is told to make their avatar walk like the “healthy” avatar.

This methodology provide the patient with visual feedback about self-motion (they can see a limp or hitch in their stride) or auditory feedback to provide them with cues on how to more efficiently. Importantly, the cueing is driven by human movement, which incorporates the missing dynamic patterns which lead to the patient’s locomotor dysfunction.

Moreover, the viewing perspective can be moved or amplified if the patient is having difficulty synchronizing with the model avatar. By mimicking the gait patterns of a healthy adult, this type of training is specifically designed to restore functional mobility in a patient population.

Equipment

The VEAR Lab is equipped with a wide range of biomechanical equipment to pursue our research program. This includes 3D motion capture, virtual reality immersion capabilities, a treadmill that simulates slips and trips, and much more.

Equipment device name or image Purpose(s)
Qualisys 3D Motion Capture hardware and software Full body 3D motion capture occurs with the hardware and software provided by Qualisys.
Vizard Software Vizard software provided by WorldViz allows for the rendering of custom virtual reality environments.
Oculus Rift headset The Oculus Rift headset offers immersive virtual reality in a lightweight device.
Head-Mounted Display A head-mounted display (HMD) provided by NVis allows for full immersion within a virtual environment. Combined with our Qualisys motion capture system, participants can navigate a large-scale virtual environment while the visual display is updated in real-time.
ActiveStep treadmill The ActiveStep treadmill by Simbex can provide simulated slips and trips in a safe environment.
Visual3D software Kinematic and kinetic data can be synchronized and analyzed in Visual3D software provided by C-Motion.
Biopac system Joint angles, stride time, heart rate, breathing rate, and EMG can all be wirelessly collected and synchronized.
Trigno system EMG and acceleration profiles can be collected wirelessly using the Trigno system provided by Delsys.
ADMP system Acceleration profiles can be used to analyze gait and posture behavior using the ADMP system.
AMTI portable forceplate Postural control is captured with an AMTI portable forceplate, which is synchronized with our Qualisys motion capture system.
portable forceplate This portable forceplate is designed for field-based testing of postural control before and after a concussion.
Xsens sensors Gait and posture acceleration profiles can be recorded using Xsens sensors.

Current Staff and Students