When I'm running 4E, I kept having the issue of bottle-necking the heroes. They'll be in the hallway going into a large, open, dynamic encounter area; my soldiers beat them on initiative. Obviously they will want to move forward to protect their squishy allied monsters. So it ends up being a long, dragged out fight between the party's defenders (who don't deal big damage and don't get hit often), and the brute/soldiers. Compound this with a party that doesn't have a lot of ranged or forced movement control options, and you can see the problem.
How do I address these issues? Do I wait and call for Initiative until after the party is in the room? Do I encourage the party to do maneuvers like Bull Rush to push the opponents out of the hallway?
It's a valid enough tactic for the monsters to use, and one parties often use, too (a lot of parties would /love/ to have a convenient choke point in every encounter, and go out of their way to engineer them), so I don't see a problem, per se, if one side of a combat wants to delay the other and/or if it can bring all it's offense to bear along a narrow front, then adopting a defensive posture at a choke point is ideal, for them.
It's a good idea to change up encounters, of course. Some even-odds encounters with Standard monsters, some Elite+Minions, or double-teaming elites, the occasional Solo - the epic big boss fight with Solo, plus a standard or two /and/ minions.
You can also do quite a variety of encounters by monster roles. An encounter with a band of skirmishers or lurkers, for instance, will have none of the issues you describe.
SO you can address the issue on your side of the screen by using more skirmishers, lurkers, and solos, and fewer combined-arms squads of soldiers-and-artillery. And by using more open-field scenarios rather than dungeon rooms and the like with inevitable choke points. You can also place items that address the problem, the occasional 'throwing' weapon to get melee-only players a ranged option, would be an example, items can add a little dose of mobility or control, too.
Also, consider that 4e tends to get grindy when other eds might fall into a death spiral, so consider it a waring sign - that you may be playing the monsters too smart, making the encounter too tough, or that your players may be slacking (which is, I'm afraid, more what it sounds like in this instance - and you have to put a lot of effort into slacking to get a broad lack of competence in range & control out of a 4e party... unless they're a bunch of Essentials Knights or something).
Your players can address the issue by playing more aggressively when this sort of thing starts to shape up - do some bull-rushing and/or improvised maneuvers to get past that front line and bring the whole party's offense to bear - and, in the medium term by taking feats to goose initiative and choosing powers with more control and ranged options, if not outright swapping out a character two.
