Musculoskeletal Biomechanics Lab

The human musculoskeletal system is a remarkable engineering system that enables voluntary movement with inherent ease in healthy individuals. Yet, its complexity makes it difficult to understand and treat orthopaedic pathologies, prevent injuries, and optimize human perfomance at large. We study musculoskeletal biomechanics using motion capture, medical imaging, and computational modeling. We rely on both traditional and nex-generation motion capture technologies, including wearable sensors, smart garments, and computer vision. Our ultimate goal is to integrate insights from our experimental and computational work in the development of effective rehabilitation and performance-optimization strategies aimed at restoring and preserving pain-free mobility throughout the lifespan.

Faculty

Eni Halilaj

Eni Halilaj

Associate Professor, Mechanical Engineering

I am an associate professor in Mechanical Engineering, with courtesy appointments in Biomedical Engineering and the Robotics Institute, at Carnegie Mellon University and an adjunct faculty member in Orthopaedic Surgery at the University of Pittsburgh School of Medicine. I currently direct the CMU Musculoskeletal Biomechanics Lab, an interdisciplinary group seeking to understand and optimize human movement mechanics.

Office
Scaife Hall 317
Phone
412.268.2183
Fax
412.268.3348
Email
ehalilaj@andrew.cmu.edu
Google Scholar
Eni Halilaj
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Projects

We are developing wearable sensing and computer vision tools for human motion tracking outside of the lab and deploying them for injury prevention, rehabilitation monitoring, and performance optimization. Additionally, we are developing portable biofeedback systems for gait retraining and evaluating them in natural environments. Our ongoing projects combine experimantal biomechanics, artificial intelligence (AI), biomechanical modeling, medical imaging, and smart-garment design. They include both healthy people and ones with musculoskeletal conditions (e.g., ACL injuries, knee OA, total joint replacement) and neurocognitive disorders (e.g., mild cognitive impairment).

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  • Graphic highlighting natural environment biomechanics research

    Wearable Sensing and Computer Vision

    The operational cost associated with traditional motion capture systems has inhibited translation and discouraged large movement analysis studies. Recent advances in computer vision and wearable sensing offer untapped potential for movement analysis in natural environments, but the effectiveness of these technologies in estimating movement biomechanics within tolerable errors remains limited. To address the shortfalls of current methods, we are working on new data-driven and physics-based approaches for the estimation of biomechanically relevant outcomes from wearable sensors and videos.

  • Graphic showing the role of mechanics in osteoarthritis

    Role of Mechanics in Injury, Disease, and Rehabilitation

    Musculoskeletal mechanics is a major contributor to the development of injuries and diseases, like osteoarthritis and eventual joint failure, but this effect is highly variable across individuals, given interactions between mechanical and biological factors. We study these interactions by evaluating tissue response to different types of mechanical stimuli (e.g., natural loading, exercise, ligament tears) via medical imaging, musculoskeletal modeling, and deep patient phenotyping. Findings from these studies should form the scientific basis of patient-tailored injury/disease prevention and rehabilitation strategies that are more effective than the current standard of care.

  • Graphic highlighting precision rehabilitation research

    Technology-Assisted Rehabilitation

    Injury prevention programs, disease-modifying interventions, and rehabilitation in orthopedics currently require significant time investment from patients and medical staff, yet they are not tailored to each patient. Our goal is to use insights from experimental and computational studies to design personalized interventions assisted by portable technologies and evaluate both their effectiveness in targeting a biomechanical outcome of interest in natural environments and their efficacy in modifying disease, improving rehabilitation, or optimizing human performance. 

    • Research team

    Evy Meinders headshot

    Evy Meinders

    Post-Doctorate

    Email
    emeinder@andrew.cmu.edu
    Headshot of Jimin An

    Jimin An

    Doctorate

    Co-Advisor
    Inseung Kang
    Email
    jimina@andrew.cmu.edu
    Headshot of Rozhan Kiani

    Rozhan Kiani

    Doctorate

    Email
    rkiani@andrew.cmu.edu
    Zhixiong Li headshot

    Zhixiong (Jack) Li

    Doctorate

    Email
    zhixionl@andrew.cmu.edu
    Vu Phan headshot

    Vu Phan

    Doctorate

    Email
    vuphan@andrew.cmu.edu
    Soyong Shin headshot

    Soyong Shin

    Doctorate

    Email
    soyongs@andrew.cmu.edu
    Headshot of Babak Tarivirdilouyasl

    Babak Tarivirdilouyasl

    Doctorate

    Email
    btarivir@andrew.cmu.edu
    Headshot of Holly Chen

    Holly Chen

    Masters

    Email
    hollyc@andrew.cmu.edu
    Headshot of Kunwoo Lee

    Kunwoo Lee

    Masters

    Email
    kunwool@andrew.cmu.edu
    Headshot of Chaeeun Lee

    Chaeeun Lee

    Masters

    Email
    chaeeunl@andrew.cmu.edu
    Headshot of Sijia Li

    Sijia Li

    Masters

    Email
    sijial2@andrew.cmu.edu
    fallback image

    Myles Robinson

    Masters

    Email
    mylesr@andrew.cmu.edu
    Headshot of Jessica Bae

    Jessica Bae

    Undergraduate

    Email
    jbae3@andrew.cmu.edu
    Headshot of Victor Li

    Victor Li

    Undergraduate

    Email
    victor8@cmu.edu
    Headshot of Julian Ng-Thow-Hing

    Julian Ng-Thow-Hing

    Undergraduate

    Email
    jngthowh@andrew.cmu.edu
    Headshot of Koharu Matsuki

    Koharu Matsuki

    Undergraduate

    Email
    kmatsuki@andrew.cmu.edu
    Headshot of Rhea Soo

    Rhea Soo

    Undergraduate

    Email
    rsoo@andrew.cmu.edu
    Headshot of Sofia Warehall

    Sofia Warehall

    Undergraduate

    Email
    swarehal@andrew.cmu.edu
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    Courses

    Course Course Name Location Units Semester Offered
    24-351 Dynamics Pittsburgh 10 Fall
    24-663 Special Topics: Biomechanics of Human Movement Pittsburgh 12 Fall, Spring
    24-665 Special Topics: Wearable Health Technologies Pittsburgh 12 Spring
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    Publications

    Articles & Book Chapters (last 5 years)


    1. Li Z, Shin S, Phan V, Meinders E, Halilaj E. "Impact of Multi-View Fusion and Biomechanical Modeling on Markerless Motion Tracking." IEEE Transactions on Biomedical Engineering, October 2025. (journal article)
    2. Wackerle AM, Joreitz R, Sprague A, Senorski EH, Halilaj E, Rabuck SJ, Lesniak BP, Hughes JD, Irrgang JJ, Musahl V, 2024 Panther Expert Group, “Freddie Fu Panther Symposium Expert Group 2024: Rehabilitation and Return to Sport After Anterior Cruciate Ligament Reconstruction Part 2: Concepts and Challenges in Return to Sport.” Journal of Orthopaedic & Sports Physical Therapy, October 2025. (journal article)
    3. Lin Y, Zhu D, Naidu A, Yu K, Harper D, Halilaj E, Weber D, Kenney D, Popchak AJ, Baratz M, Ion, A. "Personalized Bistable Orthoses for Rehabilitation of Finger Joints." In Proceedings of the 38th Annual ACM Symposium on User Interface Software and Technology (UIST '25), pp. 1–18, September 2025. (conference paper)
    4. An J, Song C, Halilaj E, Kang I. "Optimizing Locomotor Task Sets in Biological Joint Moment Estimation for Hip Exoskeleton Applications." In 2025 International Conference On Rehabilitation Robotics (ICORR), pp. 1518-1523. IEEE, 2025. (conference paper)
    5. Shin S, Kim J, Halilaj E, Black MJ. “WHAM: Reconstructing World-grounded Humans with Accurate 3D Motion.” In Proceedings of the IEEE/CVF Conference on Computer Vision and Pattern Recognition, pp. 2070-2080, 2024. (conference paper)
    6. Tong H, Halilaj E, Zhang J. “HybridOctree_Hex: Hybrid Octree-Based Adaptive All-Hexahedral Mesh Generation with Jacobian Control.” Journal of Computational Science, v. 78, p. 102278, June 2024. (journal article)
    7. Phan, Vu, Ke Song, Rodrigo Scattone Silva, Karin G. Silbernagel, Josh R. Baxter, and Eni Halilaj. "Seven Things to Know about Exercise Monitoring with Inertial Sensing Wearables." IEEE Journal of Biomedical and Health Informatics, v. 28(6), pp. 3411-21, February 2024. (journal article)
    8. Rokhmanova N, Pearl O, Kuchenbecker K, Halilaj E. “IMU-Based Kinematics Estimation Accuracy Affects Gait Retraining Using Vibrotactile Cues.” IEEE Transactions on Neural Systems and Rehabilitation Engineering, v. 32, pp. 1005-1012, 2024. (journal article)
    9. Tong H, Halilaj E, Zhang J. “Planar Unstructured Quadrilateral Control Mesh for Isogeometric Analysis Using the Advancing-Front Method and Neural Networks.” Journal of Computational Science, v.72, p. 102109, July 2023. (journal article)
    10. Pearl O, Shin S, Godura A, Bergbreiter S, Halilaj E. “IMU and Video Fusion via Optimal Control of a Biomechanical Model.” Journal of Biomechanics, v. 155, p. 111617, June 2023. (journal article)
    11. Shin S, Li Z, Halilaj E. “Human Motion Tracking with Noisy Video and Inertial Sensing Data.” IEEE Transactions in Biomedical Engineering, v. 70(11), pp. 3082-3092, May 2023. (journal article)
    12. Tan T, Wang D, Shull P, Halilaj E. “IMU and Smartphone Camera Fusion for Knee Adduction and Knee Flexion Moment Estimation.” IEEE Transactions in Industrial Informatics, v. 19(2), pp. 1-12, July 2022. (journal article)
    13. Rokhmanova N, Kuchenbecker K, Shull P, Ferber R, Halilaj E. “Predictive Modeling of Knee Adduction Moment Response to Gait Retraining with Minimal Clinical Data.” PLOS Computational Biology, v. 18, p. e1009500, May 2022. (journal article)
    14. Halilaj E, Shin S, Rapp E, Xiang D. “American Society of Biomechanics Early Career Achievement Award 2020: Toward Portable and Modular Biomechanics Labs: How Video and IMU Fusion Will Change Gait Analysis.” Journal of Biomechanics, Journal of Biomechanics, v. 129, p. 110650, December 2021. (journal article)
    15. Urish K, Lewis G, Halilaj E. “Musculoskeletal Biomechanics.” Orthopaedic Knowledge Update: 14, American Academy of Orthopaedic Surgeons, edited by LM Galatz and FM Azar: Lippincott Williams & Wilkins, January 2023. (book chapter)
    16. Whitford A, Kim E, Halilaj E, Keelan Enseki, Adam Popchack, Hodgins J. “Sensor-Based Evaluation of Physical Therapy Exercises.” Conference Proceedings of the IEEE Engineering in Medicine and Biology Society, v. 2021, >pp. 7556-7561, November 2021. (conference paper)
    17. Rapp E*, Shin S*, Thomsen W, Ferber R, Halilaj E. “Estimation of Kinematics from Inertial Measurement Units Using a Combined Deep Learning and Top-Down Optimization Framework.” Journal of Biomechanics, v. 116, p. 110229, February 2021. (*equal contribution) (journal article)

    Conference Abstracts (last 5 years)

    1. Shin S, Li S, Yiannakidis A, Li Z, Black MJ, Halilaj E. “DeepGaitLab: Synthetic Videos Improve Open-Source Markerless Motion Tracking.” American Society of Biomechanics, Pittsburgh, PA, 2025. 
    2. Li Z, Lee C, Lee K, Meinders E, Sprague A, Irrgang JJ, Musahl V, Halilaj E. “Videos Capture Functional Strength Deficits Following ACL Reconstruction.” American Society of Biomechanics, Pittsburgh, PA, 2025.
    3. Sundaram V, Rokhmanova N, Halilaj E, Kuchenbecker K. “The Benefits of Gait Retraining with Vibrotactile Feedback Outweigh Higher Perceived Mental Load.” American Society of Biomechanics, Pittsburgh, PA, 2025.
    4. An J, Halilaj E, Kang I. “Biomechanical Effects of Varying Assistance Magnitude During Level-Ground and Ramp-Ascent Locomotion Using a Robotic Hip Exoskeleton.” American Society of Biomechanics, Pittsburgh, PA, 2025.
    5. Seagars K, Uhlrich SD, Kolesar JA, Mazzoli V, Halilaj E, Delp SL. “Reduced Compressive and Shear Forces from Gait Retraining Relate to Slowed Cartilage Degeneration.” World Congress on Osteoarthritis, Vienna, Austria, 2024.
    6. Meinders E, Li Z, Sprague A, Irrgang J, Mushal V, Halilaj E. “The Quadriceps Muscles May Not Contribute to Knee Underloading in Individuals Three Months after ACL-Reconstruction Surgery.” American Society of Biomechanics, Madison, WI, 2024.
    7. Shin S, Li Z, Phan V, Black MJ, Halilaj E. “Markerless Motion Tracking in Natural Environments with a Single Moving Camera.” American Society of Biomechanics, Madison, WI, 2024.
    8. Li Z, Shin S, Phan V, Meinders E, Halilaj E. “Does Sequential Implementation of Biomechanical Constraints Improve Computer Vision Solutions for Markerless Motion Tracking?” American Society of Biomechanics, Madison, WI, 2024.
    9. Phan V, Li Z, Meinders E, Halilaj E. “Does Biomechanical Modeling Improve IMU-Based Estimation of Lower-Limb Kinematics?” American Society of Biomechanics, Madison, WI, 2024.
    10. Parola L, Halilaj E. “The Gait Lab Syndrome: How Laboratory Environments Mask Gait Differences between Healthy Individuals and Patients with Anterior Cruciate Ligament Reconstruction.” American Society of Biomechanics, Knoxville, TN, 2023.
    11. Pearl O, Rokhmanova N, Dankovich L, Bergbreiter S, Halilaj E. “Capacitive Sensing for Real-Time Estimation of Muscle Bulging in Natural Environments.” American Society of Biomechanics, Knoxville, TN, 2023
    12. Pearl O, Rokhmanova N, Dankovich L, Bergbreiter S, Halilaj E. “Capacitive Sensing for Natural Environment Rehabilitation Monitoring.” International Society of Biomechanics, Fukukoa, Japan, 2023.
    13. Tong H, Halilaj E, Zhang J. “Planar Unstructured Quadrilateral Meshes Using the Advancing-Front Method and Neural Networks.” Symposium on Industrial Applications of Isogeometric Analysis, U.S. National Congress on Computational Mechanics, Albuquerque, NM, 2023.
    14. Rokhmanova N, Pearl O, Kuchenbecker K, Halilaj E. “The Role of Kinematic Estimation Accuracy on Learning with Wearable Haptics.” American Society of Biomechanics, Knoxville, TN, 2023.
    15. Shin S, Li Z, Halilaj E. “3D Human Motion Tracking Using a Single Camera.” American Society of Biomechanics, Knoxville, TN, 2023.
    16. Phan V, Sung K, Silva R, Sibernagle K, Baxter J, Halilaj E. “Seven Things to Know about Exercise Monitoring with Inertial Sensing Wearables.” American Society of Biomechanics, Knoxville, TN, 2023.
    17. Shin S, Hodgins J, Halilaj E. “Physical-Therapy Assessment with Uncalibrated Cameras and Inertial Sensors.” American Society of Biomechanics, Knoxville, TN, 2023.
    18. Rokhmanova N, Pearl O, Kuchenbecker K, Halilaj E. “Predicting Knee Adduction Moment Response to Gait Retraining with Minimal Clinical Data.” North American Congress of Biomechanics: joint Canadian and American Society of Biomechanics Meetings, Ottawa, CA, 2022.
    19. Shin S, Halilaj E. “Markerless Motion Tracking from Multi-View Videos and Minimally Calibrated IMUs.” North American Congress of Biomechanics: joint Canadian and American Society of Biomechanics Meetings, Ottawa, CA, 2022.
    20. Pearl O, Godura A, Bergbreiter S, Halilaj E. “IMU and Video Fusion via Optimal Control of a Biomechanical Model.” North American Congress of Biomechanics: joint Canadian and American Society of Biomechanics Meetings, Ottawa, CA, 2022.
    21. Halilaj E, Shin S, Pearl O, Rokhmanova N. “Rehabilitation Monitoring with Wearables: from Physical Therapy to Natural Ambulation.” Quadrennial World Congress of Biomechanics, Taipei, Taiwan, 2022.
    22. Tan T, Wang D, Shull P, Halilaj E. “IMU-Camera Fusion for Estimation of Knee Adduction and Flexion Moments.” American Society of Biomechanics 2021, Atlanta, GA, August 2021.
    23. Shin S, Halilaj E. “Learning-Based 3-D Human Body Reconstruction from Multiview Cameras.” American Society of Biomechanics 2021, Atlanta, GA, August 2021.
    24. Thomas K, Krzemiński D, Kidziński Ł, Paul R, Halilaj E, Black M, Chaudhari A, Gold G, Delp S. “Automated Segmentation of Knee Cartilage in MRIs Using Deep Neural Networks.” Radiological Society of North America, Chicago, IL, 2020.
    25. Shin S, Rapp E, Ferber R, Halilaj E. “Combined Deep Learning and Top-Down Optimization for Estimation of Kinematics from IMUs.” American Society of Biomechanics, Atlanta, GA, 2020.
    26. Rokhmanova N, Shull P, Kuchenbecker K, Halilaj E. “Subject-Specific Biofeedback for Gait Retraining Outside of the Lab.” Dynamic Walking, Hawley, PA, 2020.
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    Outreach

    We organize Perry Initiative workshops and National Biomechanics Day events in Pittsburgh. Contact us to learn more and get involved. ▲ Back to the top

    Media mentions

    CMU Engineering

    Summer of discovery

    Five students who participated in the Summer Undergraduate Research Fellowship (SURF) program enriched their studies by conducting research related to the biomedical applications of their respective engineering fields.

    Mechanical Engineering

    MechE hosts 2024 Rising Stars Workshop

    Rising Stars in Mechanical Engineering supports female graduate students and postdocs who are considering careers in academia.

    CMU Engineering

    2024 Dean’s Early Career Fellowships awarded

    The College of Engineering congratulates Eni Halilaj, Coty Jen, and George Okeyo, the 2024 recipients of the Engineering Dean's Early Career Fellowships.

    Medscape

    Halilaj speaks on the benefits of using AI for biomechanical analyses

    MechE’s Eni Hallilaj speaks on the benefits of using AI for biomechanical analyses in Medscape. Especially for “highly heterogeneous conditions that we have not been able to fully characterize through traditional studies with limited patients,” the app allows for the possibility of having hundreds or even thousands involved in studies.

    See More Mentions

    CMU College of Engineering

    2023 Engineering Faculty Awards announced

    The 2023 Engineering Faculty Awards highlight faculty members who have shown outstanding educational, research, and service efforts. Congratulations to all of this year’s awardees!

    CNBC

    Halilaj quoted on about humanoid robots

    MechE’s Eni Halilaj was quoted by CNBC about humanoid robots. “Our body is a complex engineering system that we still do not fully understand,” Halilaj said.

    Mechanical Engineering

    NIH awards Halilaj $2.7M

    Eni Halilaj will collaborate with UPMC to predict the onset of post-traumatic osteoarthritis after anterior cruciate ligament reconstruction surgery.

    CMU Engineering

    Halilaj and Ren receive NSF Career Awards

    College of Engineering’s Eni Halilaj and Charlie Ren have received National Science Foundation CAREER Awards for their research.

    CMU Engineering

    Precision rehabilitation to prevent osteoarthritis

    Wearable sensors plus computer vision could reduce the likelihood of degenerative joint disease.

    Chan Zuckerberg Initiative

    Halilaj project making waves for biomedicine

    MechE’s Halilaj Eni’s project DeepGaitLab, funded by CZI Science, proposes to interface computer vision tools with an open-source biomechanical modeling software, facilitating the uptake of motion tracking lacking markers.

    Mechanical Engineering

    Biomechanics for teens

    National Biomechanics Day is a worldwide celebration that strives to bring the complex world of biomechanics to high school students through hands-on activities, demonstrations, and Q&A sessions with real-world professionals.

    Halilaj receives ASB Young Scientist Award

    MechE’s Eni Halilaj has won the American Society of Biomechanics Young Scientist Award. The award will be presented at this year’s ASB meeting in August.

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