One of the most touching scenes in The Lord of the Rings reads:
And so Gollum found them hours later, when he returned, crawling and creeping down the path out of the gloom ahead. Sam sat propped against the stone, his head dropping sideways and his breathing heavy. In his lap lay Frodo’s head, drowned deep in sleep; upon his white forehead lay one of Sam’s brown hands, and the other lay softly upon his master’s breast. Peace was in both their faces.
Gollum looked at them. A strange expression passed over his lean hungry face. The gleam faded from his eyes, and they went dim and grey, old and tired. A spasm of pain seemed to twist him, and he turned away, peering back up towards the pass, shaking his head, as if engaged in some interior debate. Then he came back, and slowly putting out a trembling hand, very cautiously he touched Frodo’s knee – but almost the touch was a caress. For a fleeting moment, could one of the sleepers have seen him, they would have thought that they beheld an old weary hobbit, shrunken by the years that had carried him far beyond his time, beyond friends and kin, and the fields and streams of youth, an old starved pitiable thing.
(J.R.R Tolkien, The Lord of the Rings, Book 4, chapter 8 - The Stairs of Cirith Ungol)
What physical interactions do we have there? First:
In his lap lay Frodo’s head, drowned deep in sleep; upon his white forehead lay one of Sam’s brown hands, and the other lay softly upon his master’s breast. Peace was in both their faces.
This image, almost Pietà-like, conveys Frodo's trust, Sam's care, and the broader relationship between the two. Tolkien doesn't tell us any of it - he doesn't need to. He's just shown it.
Then comes Gollum:
slowly putting out a trembling hand, very cautiously he touched Frodo’s knee – but almost the touch was a caress.
You can visualise Gollum's longing for Frodo and Sam's peace, for the intimate friendship they share, perhaps for struggling towards something bigger than oneself, or something similar - he is extending his hand towards a Pietà.
The trouble with "he extended his arms" and your other examples is that they feel almost like IKEA instructions. "Place tab A over structure B". You need the adverbs - try reading the above paragraph without them. You need the particular descriptions, like "almost the touch was a caress". It's not enough that person A touched person B - tell us how.
(Keep the Pietà to no more than one instance in your story, though - you don't want to overdo it. But for a particularly poignant scene, referring to a familiar cultural image is a possibility. Just don't explicitly say "Pietà-like". Describe it, let the reader create the image in their own mind.)