I previously worked as a graduate research assistant in the DeFrate Musculoskeletal Bioengineering Laboratory under Dr. Lou DeFrate. My research focused on quantifying cartilage deformations in the human knee, shoulder, and hip joints in vivo, using magnetic resonance imaging (MRI) and 3D solid modeling techniques. I also used novel quantitative MRI methods, such as T1rho and T2 mapping, to analyze the structure and composition of cartilage non-invasively to assess overall tissue health. Most recently, I developed image processing techniques to semi-automatically isolate bones from MR images.


  1. Heckelman LN, Soher BJ, Spritzer CE, Lewis BD, DeFrate LE (2022). Design and validation of a semi-automatic bone segmentation algorithm from MRI to improve research efficiency. Scientific Reports, 12(7825).

  2. Tamayo KS, Heckelman LN, Spritzer CE, DeFrate LE, Collins AT (2022). Obesity Impacts the Mechanical Response and Biochemical Composition of Patellofemoral Cartilage: An in vivo, MRI-based Investigation. Journal of Biomechanics, 134.

  3. Heckelman LN, Wesorick BR, DeFrate LE, Lee RH (2021). Diabetes is Associated with a Lower Minimum Moment of Inertia Among Older Women: An Analysis of 3D Reconstructions of Clinical CT Scans. Journal of Biomechanics, 128.

  4. Heckelman LN, Riofrio AD, Vinson EN, Collins AT, Gwynn OR, Utturkar GM, Goode AP, Spritzer CE, DeFrate LE (2020c). Dose- and Recovery-Response of Patellofemoral Cartilage Deformations to Running. Orthopaedic Journal of Sports Medicine, 8(12).

  5. Heckelman LN, Bucholz EK (2020b). Designing a MATLAB-based Escape Room. Proceedings of the 127th American Society for Engineering Education Annual Conference & Exposition.

  6. Heckelman LN, Smith WAR, Riofrio AD, Vinson EN, Collins AT, Gwynn OR, Utturkar GM, Goode AP, Spritzer CE, DeFrate LE (2020a). Quantifying the biochemical state of knee cartilage in response to running using T1rho magnetic resonance imaging. Scientific Reports, 10(1870).

  7. Owusu-Akwaw KA, Heckelman LN, Cutcliffe HC, Sutter EG, Englander ZE, Spritzer CE, Garrett WE, DeFrate LE (2018). A Comparison of Patellofemoral Cartilage Morphology and Deformation in Anterior Cruciate Ligament Deficient versus Uninjured Knees. Journal of Biomechanics, 67, 78-83.

  8. Taylor KA, Collins AT, Heckelman LN, Kim SY, Utturkar GM, Spritzer CE, Garrett WE, DeFrate LE (2018). Activities of Daily Living Influence Tibial Cartilage T1rho Relaxation Times. Journal of Biomechanics, 82, 228-233.

  9. Zhang H, Heckelman LN, Spritzer CE, Owusu-Akyaw KA, Martin JM, Taylor DC, Moorman CT, Garrigues GE, DeFrate LE (2018). In Vivo Assessment of Exercise-Induced Glenohumeral Cartilage Strain. Orthopaedic Journal of Sports Medicine, 6(7).

† American Society for Engineering Education conference proceedings are peer-reviewed via a multi-step, double-blind process and are highly regarded in the field of engineering education.

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Figure 1. Each participant completed a multi-visit magnetic resonance imaging (MRI) and exercise protocol. The first testing day consisted of a 45-minute rest period followed by a baseline (pre-exercise) double echo steady state (DESS) MRI, a 10-mile run on a treadmill at a self-selected pace, and a post-exercise DESS MRI. The participants returned the following morning for an additional 45-minute rest period followed by a recovery DESS MRI. The entire protocol was repeated 2-3 weeks later, but each participant instead ran 3 miles at his mean mile pace from the 10-mile run.

Figure 2. T1rho maps for a single participant before, immediately after, and 24 hours after running 10 miles (16.1 km). Red and blue are indicative of regions with high and low T1rho relaxation times, respectively.

*Figures above from Heckelman et al. (2020a & 2020c).

Figure 3. (A) Patellar cartilage thickness maps for a single participant generated from the pre-exercise (PRE), post-exercise (POST), and recovery (REC) magnetic resonance imaging scans for both the 3- and 10-mile runs. Red represents areas with thicker cartilage, whereas blue represents areas with thinner cartilage. (B) Patellar cartilage strain maps for a single participant, quantifying the immediate effect of the 3- and 10-mile runs. Red represents areas in which the cartilage thickness decreased (compressive strain), whereas blue represents areas where the cartilage thickness increased.

Research Statement