In the above-titled lineage of vipassana, it is said that as soon as there is contact through the sensory bases, sensations are produced on the body.
Why and how does this happen?
And, what are the type of sensations arising on physical body -- for example, tingling, etc., etc.?
Not sure how Goenka tradition explains it, but Contact(Passa) means the union of form,sense & sense consciousness. That always causes feeling(Vedana) to arise according to Paticca-samuppada(dependant arising).
Like Sankha said, there are a few things necessary to come to an experience of sensations. Contact is when those factors come together. So far, so good.
Bodily sensations are a very rich study object, imho. There is at least always present: the earth element (hard, soft and so on), the wind element, the fire element and the water element. Those four (plus four others) form the mix of matter that is always there when it comes to material elements. But that mix is variable, meaning that the amount of earth element is not always the same, same goes, of course, for all the other elements.
Let's say you experience a tingling sensation. If you unpack this you'll find that in that 'mix of matter' there is a lot of wind element present. If it is a sharp, cold tingling sensation then there is not a lot of fire element present. If the tingling is warm and smooth, there will be more fire element. When you experience a very dense sensation, there will probably a lot of earth element there and less wind element. And so on.
Like with the mind states matter also comes and goes. It has, like the mind, its causes and conditions. Depending on how precise you want to know what's going on the Paticca Samuppada might not be enough. You should also dive into the 'Compendium of Matter' and the 'Compendium of Conditionality' (both are part of the Abhidhamma Sangaha).
Further, as Sankha states, every experience contains also an affect, the way a sensation feels. Bodily sensations can be experienced as pleasant or unpleasant; mind states can be experienced as pleasant, unpleasant or neutral.
Hope this helps.
If by 'why', you are asking in a physiological sense then its because our body is not a static mass of matter. It's because of Annicca i.e. there is a continous activity going on even on the most superficial level of your skin. During Vipassana you concentrate on the small region which leads to increased awareness of such activity on your skin, depending on the activity you might feel different sensations may it be tingiling or itching etc. So the sensations is manifestation of Annicca, and that is the wisdom you have to attain through Vipassana, to realise this very nature of Annicca.
If your question pertains to physics of it like, how does this happen? It happens in a way like, the activity on your skin produces related response on the nerve endings near the skin, these nerve endings take the signal to the brain and related consciousness is produced.
And the types of sensations are told by S.N Goenka like tingling, irritating, prickling, pleasent or unpleasent.
