Context - The existing literature on particle motion at the fundamental level is sparse. Particles, whether classical or quantum, are assumed to move with a continuous (even if uncertain) velocity. Purpose - The work prospects for a descriptive theory of particle motion from a non-local hidden-variable (NLHV) perspective. This is worth attempting for the potential to better understand fundamental dynamics and kinematics. Method - The new physics provided by the cordus theory was used to infer the mathematical representation of the energisation behaviour of the inner structures, specifically the reactive ends. From this the motion function of the particle as a whole was determined. Findings - In three dimensional space the motion of each reactive end is an irregular spiral displacement locus. The motion comprises a movement phase and a brief immobile phase. This is called a ‘gait’ as it is reminiscent of biological locomotion. Originality - A novel theory of particle motion is offered. The theory predicts that motion comprises a complex spiral locus of the particle. This is unique among theories of physics. Further contributions are the provision of explanations for several physical phenomena: ponderomotive force, the nature of momentum, and bremsstrahlung radiation. Specifically, the theory explains why photon emission would be increasing concentrated in the forward direction with increased electron energy. The theory provides a means to bridge quantum mechanics and special relativity, because it accommodates both particle uncertainty and field transmissions.