Did St. Joachim prevent the transmission of original sin to Mary by overcoming concupiscence?
Yes, St.John of Damascus a Greek Father and Doctor of the Church speaks directly of the "spotless seed" that comes out from St.Joachim;
“O most blessed loins of Joachim from which came forth a spotless seed! O glorious womb of Anne in which a most holy offspring grew.” John of Damascus, Homily I (ante A.D. 749).
"O blessed loins of Joachim, whence the all-pure seed was poured out! O glorious womb of Anna, in which the most holy fetus grew and was formed, silently increasing! O womb in which was conceived the living heaven, wider than the wideness of the heavens." [Ibid, 2; "Fetus" means offspring in Latin. We mention this because in modern societies the term has lost its Latin and (and true) definition and has come to signify a "non-person" for all practical purposes, a distortion for political manipulation------The Web Master]
“She is born like the cherubim, she who is of a pure, immaculate clay.” Theotokos of Livias, Panegyric for the feast of the Assumption, 5:6 (ante A.D. 650).
St.Catherine Laboure prayerful answer is Yes, as Mary ordered her to depict a medal with the powerful symbols and prayer.
"O Mary conceive without sin , pray for us who have recourse to Thee."
The Miraculous Medal (French: Médaille miraculeuse), also known as the Medal of Our Lady of Graces, is a medal, the design of which was originated by Saint Catherine Labouré following her apparitions of the Blessed Virgin Mary1 in Rue du Bac, Paris, France, and made by goldsmith Adrien Vachette.
The word "conceive without sin", is a testament that the "transmission of original sin and all stain of sins was prevented.
Note: *We are only talking first of generating flesh thru "marital act" that would lead to conception and not on the creation of Mary's soul which is a separate phenomenon.Mary's soul is created only by the sole action of God. Mary clearly revealed the prayer to be invoked upon by all Her children depicting Her as "conceived without sin" therefore the "transmission of original sin was really prevented" by the "marital act free from concupiscence".*
This will be the contrasting verse when King David confessed the state of his conception;
Surely I was brought forth in iniquity; I was sinful when my mother conceived me. (Psalm51:5)
We now go to complete removal of the concupiscence of St.Joachim how it was accomplished by God as revealed by the vision of Blessed Catherine Emmerich;
To perfectly remove or wash away the stain of original sin or the concupiscence, the angel gave St.Joachim;*
The angel "gave him a shining morsel to eat and a luminous liquid to drink from a gleaming little chalice which he held between two fingers.
JOACHIM RECEIVES THE BLESSING FROM THE ARK OF THE COVENANT.
I saw now that the angel touched or anointed Joachim’s forehead with the tip of his thumb and forefinger, and that he gave him a shining morsel to eat and a luminous liquid to drink from a gleaming little chalice which he held between two fingers. It was of the shape of the chalice at the Last Supper, but without a foot. It seemed to me, too, that this food which he put in his mouth took the form of a little shining ear of corn and a little shining cluster of grapes, and I understood that thereafter every impurity and every sinful desire left Joachim. Thereupon I saw that the angel imparted to Joachim the highest and holiest fruit of the blessing given by God to Abraham, and culminating, through Joseph, in the holy thing within the Ark of the Covenant, in the presence of God among His people. He gave Joachim this blessing in the same form as I had been shown before, except that while the angel of benediction gave Abraham the blessing from himself, out of his bosom as it were, he seemed to give it to Joachim from out of the Holy of Holies. 30
Note: The angel describes the morsel and the drink this way; "It seemed to me, too, that this food which he put in his mouth took the form of a little shining ear of corn and a little shining cluster of grapes, "
The host is wheat coming from corn and the wine is coming from grapes a perfect description of the Holy Eucharist the "body & blood" of Jesus Christ offered at the celebration of the Holy Mass.
In closing, the Mystery of removing the "concupiscence" was now revealed by the vision of Blessed Catherine Emmerich and Our Lady apparition to St.Catherine Laboure reveals the She was indeed "conceive without original sin". Without even mentioning the Dogma of Immaculate Conception, just by merely focusing on "marital act free from concupiscence" we prove that St.Joachim by the merit of the graces won by Jesus Christ was cleaned of all stain of original sin.