Just about all forms of pious or reverential actions are entirely optional in the CofE. That's where we get our reputation for being 'unruley' Something I have not seen since a young lad, some 50 years since, is genuflecting at the words in the Nicene Creed, ", And was incarnate by the Holy Ghost of the Virgin Mary, And was made man", standing again, still east facing, and continuing, "And was crucified also for us . . . This was to respectfully acknowledge the humility of Christ. Some of the older choir members often didn't manage to get back on their feet until Pontius Pilate had come and gone. Not so sure my arthritic knees would allow me a sprightly resurrection even by the time Pontius gets a mention, nowadays. In our case it was the entire choir who did it, but it was entirely optional for anyone in the congregation. It seems now that such physical demonstrations of devotion are mostly seen in charismatic churches. Usually sporadically at much less specific moments in the liturgy, if they can be said to actually have one.