It's been awhile since I've been here--anywhere on SD.net. I should really make more of an effort to stick around!
After watching DS9 Season 4 and 5 and anxiously waiting for Season 6 (Nov. 4) I remember certain discussions here about Klingon prowess in battle and the oft claimed but never proven stipulation that Klingons were stronger than humans.
Hiya Stravo.
In the past, I've demonstrated that some Klingons are stronger than the average adult human male, but as Lord Mike said, "super strength"--that which is beyond us altogether--is indeed a myth.
Allow me to elaborate.
For:
Worf complains to Jadzia at one point about having to live his life always concerned and holding back unless he hurt the far more fragile humans and recounts a story where as a teen he headbutts another teenage human and shatters his neck.
The parasite aliens in Conspiracy thought it a feat of strength to go up against Worf. (and handed him his ass)
Jem'Hadar consider Klingons more on their par in terms of strength and fighting prowess (though many of these 'super' soldiers get their asses handed to them by humans and Kira Noris.)
While we're talking about dialogue, I should mention Harry Kim's fantasy of being "as strong as a Klingon." And since we know something of Vulcan strength, I suppose Sisko's remark about Worf's strength (inferred) against a Vulcan crew is admissable too ("Take Me Out to the Holosuite").
As with anything, however, I prefer to focus on observed feats of strength. Most of that dialogue could easily be blown off as bullshit, especially Harry Dimwit's comment.
1--Kruge lifted Kirk a half meter off the ground with two hands (ST III);
2--Worf lifted some Federation political-type off the floor single-handed, then casually tossed him a meter backwards ("Let He Who Is Without Sin...");
3--Gowron and/or Martok fought with Worf in hand-to-hand, neither combatant vastly stronger/weaker than the other;
4--You're on the right track, Enola: Torres wrestled and simply overpowered Vulcan Ensign Vorik ("Blood Fever"):
http://www.uss-voyager.bravepages.com/ep58b.htm.
I prefer to discard 4. Vorik was in Pon Farr, and it seems Vulcans aren't physically up to snuff when so afflicited: McCoy said Spock didn't stand a chance against Stonn "in his condition," which must refer to Pon Farr ("Amok Time"). Torres was also sick, under the influence of something, or otherwise potentially abnormal in that episode as well.
Still, I figured I'd point it out.
3 does little save to demonstrate that we've seen at least four Klingons with strength somewhere in the same ballpark. As such, even if we regard burlier guys like Worf or Martok as exceptionally strong, smaller Klingons like Gowron and Kruge are strong too.
Therefore, 1 and 2 are where I'd direct most of my focus.
It's difficult to judge just how strong Kruge was in 1; I can really only call on my oft-quoted weight training experience to determine anything. (Be warned! I know it probably gets tiresome.) Lifting people at strange angles is different than pushing a barbell overhead, so we need examples of people lifting other people, basically.
Unfortunately I don't know much about that. All I can say is, not too long ago, I was joking around with a high school kid at a local hobby shop.
He ribbed me about being big but probably not strong at all. He knows this is untrue, but was just playing around. For kicks I grabbed him by the armpits and hoisted him up into the air.
I didn't have trouble doing that. He weighs 175 or so. I haven't tried, but I could probably do something similar with a guy ~50 lbs. heavier. At that point I'd be really struggling, however, and I doubt I could do any more.
I don't know exactly what Kirk weighed in ST3, but Kruge lifted him from a more disadvantageous angle (hands very close together). As such, even if Kirk was "only" 200-210, Kruge's strength is probably comparable to mine or he might be a bit stronger.
(Bastard...but I digress
)
Based on beginners I've trained, and if you averaged performance on lots of basic lifts, I figure I'm 3, but probably not more than 4 times stronger than the average untrained man.
That's pretty simple: if Kruge can do something I'd struggle with, and isn't necessarily his upper-limit, he's probably thrice the average man's strength. Say it's in that general vicinity anyway.
2 is even more difficult to quantify. Worf yanked that guy off the floor single-handed, then had enough energy left to toss him away. I couldn't even begin to do that with an adult, nor am I inclined to try.
So, at a rough guess, I'd say Worf is probably as strong as a good powerlifter. He should be able to press more than 300 lbs. overhead, translating to a ~500 lbs. bench press. If his lower body strength was proportionate, he'd squat and deadlift somewhere around 700 lbs., making him a good 5 times stronger than the average man.
Needless to say, that's much more than I'd expect from someone with Mike Dorn's build. So, if Worf's not a total aberration, you could conclude Klingons are stronger than us pound for pound; BUT, just as with people, a heavier, more muscular Klingon like Worf is not indicative of the AVERAGE Klingon.
Against:
Klingons routinely man handled by Tailors (Garak) Cardasians (Dukat) Humans (various starfleet officers, an older slower James Kirk in St III hands Kruge his ass) and most telling of all a pregnant Kira Noris. There is also evidence of Ferengi being able to batleth fight with proud Klingon warriors
Your original statement was thus: "I remember...the oft claimed but never proven stipulation that Klingons were stronger than humans."
Well, what do other species have to do with this?
We don't have a quantification of Cardassian, Bajoran or Ferengi strength--just conjecture based on such things as a Ferengi's
height 
Those examples might still be useful but I'd put them on the back burner...from what you've cited, only Kirk vs. Kruge directly addresses your question.
Furthermore, with all respects, as stated it reads like a false dichotomy: "Either Kruge whips Kirk's ass, or he's not significantly stronger than Kirk."
I've run across people who I'm sure could give me a good fight or kick my ass outright (again, I didn't bother to find out), and I'm sure I have a marked strength advantage over the guys I have in mind.
Conclusion: there's more to fighting than sheer strength, especially when the disparity is less than 5 to 1. So, saying a few Ferengi managed to get Worf on the ground isn't proof of...well, anything but they can do just that. It certainly doesn't mean that Klingons and humans are roughly matched.
For clarity's sake, it bears repeating: Klingons don't have "super" strength. Their average strength-weight ratio seems to be somewhat greater, but a very highly trained man could match what we've seen Worf do. Some men could probably do better.
That brings us to Sir Sirius' excellent point: are Klingons naturally this strong, or is that strength the product of intensive training?
Since we've never seen a Klingon working with weights, or moving around in a high gee holodeck simulation, I'd say the latter explanation is unsubstantiated but certainly possible.
Again, though, it could always be a bit of both.
