Affordably estimating ground reaction forces is a challenge in austere settings. OpenCap permits joint kinematics estimation, however, measuring ground reaction forces (GRF) has remained elusive [1]. GaitDynamics was developed to overcome challenges of estimating ground reaction forces of walking and running. Lower limb prosthesis users have asymmetrical stance phase features which can be observed in GRF analysis. This study examined if GaitDynamics estimated GRFs in lower limb prosthesis users was sensitive enough to observe differences in amputee walking kinetics. Three experienced transfemoral prosthesis users approved by the St. Mary's University ethical review committee walked on a split-belt treadmill while their gait was recorded using OpenCap on two iPhones. Data processed via OpenSim and GaitDynamics estimated vertical ground reaction forces (vGRF) for qualitative limb comparison. GaitDynamics successfully discriminated between prosthesis and non-prosthesis limbs as observed by longer duration of GRF on non-prosthesis and marked differences in peak vGRF between limbs across all participants. Prosthesis users evidenced markedly lower first peak vGRF than non-prosthesis limb 748.3 (21.7) and 790.9 (70.5) for participant 1 (0.4 m/s), 740.7 (8.7) and 742.7 (73.8) for participant two (0.5 m/s), 855.6 (39.1) and 750.5 (55.8) (0.6 m/s) for participant three. GaitDynamics accurately estimates vGRF in prosthesis users, capturing limb differences consistent with existing literature. Despite a small sample size, it serves as a valuable tool for kinetic estimation in resource-limited clinical and educational settings.