Forget overwhelming attack, dude, go Passive Way. It gets you combat expertise, which opens up improved trip. All you got from Overwhelming attack is a feat that you'd take anyway. Use fighter levels to pick up improved bull rush and power attack.
The feats you need are combat reflexes, knockback, power attack, improved bull rush, shock trooper, Knockdown, and Cleave. You get 3 bonus feats with that build, and 5 general feats, leaving you a bit feat starved...
What I'd do is swap those Shou Disciple levels. You can use Snap Kick if you want to get an extra unarmed attack and use an Unarmed Swordsage, which has unimpressive damage, but here's the kicker: Replace those monk levels with fighter levels, netting you -1 feats, but giving you Dungeoncrasher +4, for +8d6 damage on a bull rush into a wall. Then, You can pick up combat reflexes, perhaps through normal monk levels, perhaps through some other thing, and get Thicket of Blades as a stance from Crusader, which leaves you with 10 levels so far, Fighter6/Crusader2/Monk2, or Fighter6/Crusader2/Lion Totem Whirling Frenzy Barbarian1/Swordsage1, and then you can fill out the rest of your build with War Hulk 10, and get a Skillful weapon, which grants you BAB equal to 3/4 your hit dice.
This basically allows you to charge in and pounce with 4 attacks that hit everything you threaten, and take a -15 penalty to AC in order to gain a +30 bonus on your bull rush, with a total modifier of, like +60, knocking everything back at least 30 feet unless it's super collossal, and this number only gets bigger if you have a friendly party enlarger. Anything knocked into a wall takes 8d6+1-1/2 your STR modifier, +30 power attack damage, and everything trying to get back at you gets whirlwinded back into the wall.
It's quite feat intensive but this basic build skeleton is my favorite Melee build, because it can actually competently perform combat maneuvers such as bull rush, trip, disarm, and grapple, albeit it's not quite the best grappler in the world.
I do see the synergy with Shou Disciple adding to the knockback-ability by adding double damage, but you can get quite a lot more damage by using shock trooper to reliably hit anything for incredible damage and guarantee it will not get back up. Remember, you don't have to bull rush on the first attack, you can wait until the 4th attack, which is still at a +40 or so between your 50 odd strength and any bonuses the party might be packing. Plus, the swift action jump maneuvers will help you get into the fray and add Leap attack for more Power Attack damage.
You know, a mountain raging Frenzied Berserker might actually be able to get higher bonuses to knocking people back, but it can't quite knock back everything within a 20 mile radius.
This build will want to wield a spiked chain, and if you can get it valorous, more power to you. Feat load ends up
Spiked Chain prof(though if it's Skillful I believe that you're proficient in it)
Power Attack
Improved Bull Rush
Combat Reflexes
Knockback
Knockdown
Shock Trooper
Cleave
Great Cleave(hey, you might actually make use of this one)
Leap Attack
1 more feat.
If you can get a belt of permanent or at-will augmented expansion, that will get you Huge size, meaning your reach with the chain is 30 feet. You might actually want those monk levels after all, seeing as how you don't need the extra feats but they are nice. This build also has incredible fortitude saves and decent reflex saves coupled with evasion, and you might be able to afford steadfast determination (drop great cleave for it).