References – AN 5.29: Walking Meditation 
“My body does not physically handle sitting or stationary positions for long periods of time. I would like to do more walking meditation. Walking has a lot more distractions. Can you give some specifics on where to put my focus? Rise and fall of breath, feet, skeleton moving? Where to look, etc. Is it possible to achieve the same level of calmness, concentration and insights when the body is moving and you cannot close the eyes or keep focus on one spot?” Answered by Ajahn Pasanno. [Posture/Walking] [Proliferation] [Calming meditation] [Insight meditation] // [Mindfulness of breathing] [Buddho mantra]
Sutta: AN 5.29: Benefits of walking meditation.
2014 Thanksgiving Monastic Retreat, Session 5, Excerpt 15
“Can jhana occur in walking meditation?” Answered by Ajahn Pasanno. [Jhāna] [Posture/Walking ] // [Concentration] [Ajahn Viradhammo]
Sutta: AN 5.29: Walking Meditation.
The Four Foundations of Mindfulness [2015], Session 19, Excerpt 5