Wearable technologies enable continuous, non-invasive monitoring of cardiovascular health, promising for tracking dynamic responses during exercise. Photoplethysmography (PPG) is a simple and cost-effective sensing modality, but its accuracy during movement remains a challenge. This study investigates motion-induced hemodynamic effects on in-ear PPG pulse wave morphology during heart-paced walking. We hypothesize that motion artifacts partly arise from physiological effects induced by body motion, such as blood inertia and wave reflections. The 12 healthy participants (6 female, 28±2 years) walked on a treadmill, guided by auditory signals to synchronize their steps to either systole (R-wave) or diastole (45% RR interval) of the cardiac cycle, while recording in-ear PPG, electrocardiogram and chest acceleration. PPG pulse wave amplitude and morphology varied significantly during heart-paced walking. Diastolic stepping resulted in a consistent morphology downward deflection after 50% RR interval, while systolic stepping yielded a 0.06 V higher peak-to-peak amplitude (Cohen’s d=1.08). Our findings highlight the potential of in-ear PPG to capture physiological changes during dynamic conditions and raises questions about pulse wave morphology in the periphery during walking. Further studies are needed on extracting motion-induced hemodynamics in less controlled conditions.