And just to provide counter-balance, lest anybody think that this is a settled matter and all the experts agree:
A different case is the practice in which some people adopt the “orantes” posture during the Our Father, praying like the priest, with hands extended.
In some countries, Italy, for example, the Holy See has granted the bishops’ request to allow anyone who wishes to adopt this posture during the Our Father. Usually about a third to one-half of the assembled faithful choose to do so.
Despite appearances, this gesture is not, strictly speaking, a case of the laity trying to usurp priestly functions.
The Our Father is the prayer of the entire assembly and not a priestly or presidential prayer. In fact, it is perhaps the only case when the rubrics direct the priest to pray with arms extended in a prayer that he does not say alone or only with other priests. Therefore, in the case of the Our Father, the orantes posture expresses the prayer directed to God by his children.
Some people hold hands during the Lord’s Prayer, while others hold their hands out like the priest. Is there a prescribed posture for the Our Father?
No position is prescribed in the Roman Missal for an assembly gesture during the Lord’s Prayer.