N. Ratnakumar, K. Akbaş, R. Jones, Z. You, and X. Zhou, "Predicting Sit-to-Stand Motions with a Deep Reinforcement Learning Based Controller under Idealized Exoskeleton Assistance," Multibody System Dynamics, 2024, doi: 10.1007/s11044-024-10009-1.

R. Jones, N. Ratnakumar, K. Akbaş, and X. Zhou, "Delayed COM Feedback in Elderly Humans Leads to Greater Muscle Co-Contraction and Altered Balance Strategy under Perturbed Balance: a Musculoskeletal Study," PLOS ONE, 2024, doi: 10.1371/journal.pone.0296548.

N. Ratnakumar, N. Suguneshwaran, M. Vijendran, T. Thanihaichelvan and A. Arulanantham, "A study of three-dimensional (3-D) printed prosthetic upper limb models in local context," Materials Today: Proceedings, vol. 23, no. AMCEHA, pp. 8-11, 2019, doi: 10.1016/j.matpr.2019.05.348.

C. Steve, N. Ratnakumar, and X. Zhou, "Learning Multi-Mode Musculoskeletal Motion for Natural Walking and Running Gaits," in Proceedings of the 9th International Digital Human Modeling Conference (DHM 2025), Loughborough, UK, 2025.

M. Tohfafarosh, N. Ratnakumar, and X. Zhou, "Interactive Gait Rehabilitation through Gamified Real-Time Biofeedback and Adaptive Hip Exoskeleton Assistance: A Preliminary Evaluation," in Proceedings of the International Consortium of Rehabilitation Robotics (ICORR 2025), Chicago, IL, 2025.

S. Xu, R. Jones, N. Ratnakumar, K. Akbaş, J. Powell, Z. Zhuang, and X. Zhou, "Impact of Self-Contained Breathing Apparatus Weights on Firefighter's Kinematics During Simulated Firefighter Tasks," in Proceedings of the 15th International Conference on Applied Human Factors and Ergonomics, Nice, France, 2024.

M. Marena, N. Ratnakumar, R. Jones, X. Zhou, S. Das, and B. Shen, "Predicting Metabolic Rate for Firefighting Activities with Worn Loads using a Heart Rate Sensor and Machine Learning," in Proceedings of the IEEE-EMBS 19th International Conference on Body Sensor Networks: Sensor and Systems for Digital Health, Boston, MA, 2023, pp. 1-4, doi:10.1109/BSN58485.2023.10331063.

N. Ratnakumar, V. Devulapalli, N. Deepak, and X. Zhou, "Prediction of Walking Kinematics and Muscle Activities under Idealized Lower Limb Exoskeleton Assistances," in Proceedings of the 7th International Digital Human Modeling Symposium, vol. 7, no. 1, p. 23, Iowa City, Iowa, 2022, 9 pages, doi:10.17077/dhm.31769.

N. Ratnakumar and X. Zhou, "Optimized Torque Assistance During Walking with an Idealized Hip Exoskeleton," in Proceedings of the International Design Engineering Technical Conferences & Computers and Information in Engineering Conference, Online, Virtual, 2021, doi:10.1115/DETC2021-71376.

K. Kumarage, H. Wickramarathna, M. Vijesundaram, M. Vijendran, N. Ratnakumar, and T. Thanihaichelvan, "Design and experimental validation of an optimized wrist powered 3D printed mechanical transmetacarpal prosthesis," in Proceedings of the 14th Conference on Industrial and Information Systems, Kandy, Sri Lanka, 2019, pp. 63-68, doi:10.1109/ICIIS47346.2019.9063259.