Answered by Legionary of Christ Father Edward McNamara, professor of liturgy and sacramental theology and director of the Sacerdos Institute at the Pontifical Regina Apostolorum university.
Q: During the COVID pandemic, as I have been attending various parishes for weekday Mass, I see a variation at the act of contrition. Is it both the clergy and the congregation who strike their chests three times, or only the congregation? I notice that some of the priests do not strike the chest at all, and others place their hand on their chests without striking. – J.L., Ann Arbor, Michigan
A: The rubrics are not specific on this point. the Latin rubric in the ordinary form says: “[P]ercutientes sibi pectus,” whereas the extraordinary form specifies that the breast should be struck three times.