Podcast: Correlation of Physical Performance and Patient-Reported Outcomes Following Total Ankle Arthroplasty

Functional recovery following total ankle arthroplasty (TAA) is assessed with patient-reportedmetrics, but physical performance tests may allow for a more accurate assessment of patientfunction. We quantified correlations between patient-reported measures and physicalperformance tests in patients after TAA to determine the usefulness of physical performancetests in post-TAA assessment.

The lack of strong correlations between the 2 sets of metrics indicates that they provide different information about a patient’s recovery following TAA. Therefore, it is important to include both sets of metrics in post-TAA assessments to better understand operative success and functional recovery.


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When TAA Fails: OREF grant recipient assesses treatment options

End-stage ankle arthritis results in severe pain, deformity, and functional disability. Although both ankle fusion and total ankle arthroplasty (TAA) are effective treatment options for the condition, TAA has become more common because it preserves mobility in the ankle and may protect surrounding joints from increased wear.

Studies have shown that survival rates of ankle implants have improved over the years, yet there is still little to no information about best practices following an implant failure. How do the outcomes of revision ankle arthroplasty compare with primary arthroplasty outcomes? And how do the outcomes of revision arthroplasty compare with ankle fusion for treating a failed total ankle arthroplasty?

By: Jay D. Lenn

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Virginia Tech to Use Novel Sports Testing Service from Quest Diagnostics to Improve Student Athlete Performance

Members of the Virginia Tech football and women’s soccer team are now using customized insights from biological data to help team performance to peak levels through a new collaboration between Virginia Tech, competitive member of the elite Atlantic Coast Conference, and Blueprint for Athletes from Quest Diagnostics (NYSE: DGX), the world’s leading provider of diagnostic information services.

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Undergraduate researcher looks for ways to prevent and recover from running injuries

As a rising sophomore and runner at Gannon University, Mackenzie Wenrick hit the research jackpot when she learned she would do a summer research project with Robin Queen, associate professor in biomedical engineering and mechanics and director of the Kevin P. Granata Biomechanics Lab. Right in line with her athletic endeavors, Wernick is researching how fatigue affects a person’s loading symmetry when they run.

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Motion Analysis

The equipment used in the Granata Lab for monitoring three-dimensional kinematics are state of the art motion capture systems (Qualysis INC, Gothenburg, Sweden).  One system is comprised of ten digital cameras (OQUS 7) that can sample between 3 and 12 megapixels at variable frame rates between 300 and 1100 frames per second at full resolution. Another similar system is comprised of eight digital cameras (MIQUS M1). These cameras are connected to one another and connected through Ethernet cables to the main data collection computers which are further linked to the Qualisys online web service.  The OQUS 7 and MIQUS M1 cameras are used in conjunction with the QTM software (Qualisys, Gothenbjurg, Sweden), which allows data to be collected in real-time.  The real-time collection and display of 3D data allows the lab staff the ability to complete biofeedback projects and provide immediate information to the subjects and patients that are being assessed in the lab.  In addition to the QTM software, which is used for data collection and reduction, the Granata Lab uses Visual 3D (C-Motion, Germantown, MD) software for the processing and reduction of all motion analysis data.  Finally the lab utilizes custom written Matlab software to complete any additional data processing.

Force Plates

The Granata Lab has four AMTI (Watertown, MA) force plates, which are mounted in the floor along a 20 meter walkway.  These four force plates are mounted on a rail system allowing for them to be moved around in various configurations to optimize data collected based on the specific research study.  The force plates can be used to monitor ground reaction forces in the anterior/posterior, medial/lateral, and vertical directions.  In addition, these force plates will calculate the free moment about each one of the previously mentioned axes.  The force and moment data obtained from these force plates can be used to understand both ground reaction forces as well as joint moments, in conjunction with kinematics data, during a wide variety of activities.  In addition to the four imbedded force plates the lab also has 2 portable force plates (bi-axial).  These portable plates are used for the collection of biomechanical data in various settings  as well as being used for demonstrations at off-site facilities.


The Granata Lab currently has a pedar-X in shoe pressure measurement system (St. Paul, MN).  The pedar-X system is used to monitor the pressure beneath the foot while the subject is wearing shoes.  As part of this system the Granata Lab currently has 7 pairs of insoles ranging from a women’s size 7 through a men’s size 13.   Each insole contains 99 sensors that are can be used to monitor the pressure, force, contact area, contact time, force-time integral, and the timing of the peak pressure.  Once the data has been collected the foot can be divided into various regions in order to examine how specific sections of the foot are being loaded during different activities. The pedar-X system can be used to answer questions related for orthotic design and fabrication as well as specific questions about shoe wear.  The system can be used in isolation or can be time synchronized with the force plates and motion capture system for combined data collection capabilities.


The Granata Lab currently has 10 loadsol insoles for the collection of in-shoe pressure data (St. Paul, MN).  The loadsol system is used to monitor the pressure beneath the foot while the subject is wearing shoes similar to the pedar-X system.  Each insole in the loadsol system is a single sensor and is able to be collected through an iDevice (iPod, iPad, iPhone) to allow for collection of data in various settings outside of the lab.  These insoles provide the force time curve for both the left and right foot.  From this information custom matlab codes are used to determine the peak pressure, loading rate, and impulse during a variety of activities in various settings.  The loadsol insoles allow for real-time data collection as well as biofeedback to the subjects during a variety of activities from climbing stairs to running and jumping.

4-Channel EMG System

The Granata Lab has a telemetry based EMG system (Delysis, Natick, MA).  This telemetered system allow for the collection of EMG data without having the subject connected directly to the computer during testing.  The EMG system contains 4 channels, each has an individual transmitter that is a 1 inch square block.  This system allows for much easier data collection during all tasks, but specifically during more dynamic tasks such as running, cutting and jumping.  The EMG system can be used in isolation or can be integrated and time synchronized with the motion capture, force plate, and pedar-X systems depending on the research question.