ACTIONgolfkneeKoepkaMcIlroyPowerSpiethswing golf swing July 5, 2018 3 Comments Golf swing knee action for power on Koepka, McIlroy, Spieth admin Take a look at how all these golfers straighten up their legs at impact for extra power. Reblogged 4 months ago from www.youtube.com admin 3 Comments as always, great introspective on how the young guns get that power. Almost a Moe Norman lateral move. Knees open up. However Bobby, these guys do not always hit it down the middle. Actually after impact is what I see .