Just to enlarge on the whole pause thing, because I didn’t really explain my reasoning and I don’t want to be that guy who expects to be belived without explanation.
Pausing is generally done at the bottom of the lift (in the hole or on the chest). The muscles are mostly as stretched as they’re going to be, and that’s broadly the point at which they’re most likely to get damaged. Obviously we can get fucked up at any point in a lift, but the bottom is one where a lot of factors come into play making it riskier. So that’s the increased risk of injury side of it, mostly at any rate.
Pauses also make that bottom part harder so the fatigue burden both at the time of training and in recovery is higher. You’re combining a riskier position with increased fatigue. That isn’t going to help injury risk at all.
Now, in the context of rehab, pauses can be much more useful. You won’t be using much weight and they can function as a kind of weighted stretch as well as a point where you learn to keep yourself in a safe position. The big difference is that in the context of rehab, you aren’t going to be training that movement normally. Loads will be much lighter, volume will probably be much lower so fatigue will be minimised. Combining all that lets pause work be a lot safer. We also aren’t training the lift itself so much as preparing the body to train the lift after getting damaged and being repaired.
In terms of training effect, pausing is something that can backfire quite easily. First of all, if you pause a lift often, you train yourself to stop just at the point where you should be initiating very forceful acceleration. Secondly, coming out of a pause we tend to move more slowly simply because it is taxing to hold weight in that position. So we end up training ourselves to move slowly out of a position we should be exploding. That combination of stopping at the point of reversal and then coming out of it slowly can easily result in losing a lot of exposiveness. I think it’s similar to the idea of weighted bats making you swing faster when in reality it does the opposite.
In this respect, pausing is best used as sparingly as possible. For example with bench, it can be used in the short period before a meet to accustom us to waiting for a press command. It can be implemented sporadically for squats simply as a means of accumulating fatigue. In both scenarios, it is not something we train much at all. Three or four sets in a week, perhaps, for no longer than three or four weeks. Then no pauses for several months.
The other aspect of pausing is its use as a means of teaching correct position (@whang this may apply for you). On the face of it, it makes sense. To learn correct position, we pause in it. Except there are some issues. The first is that we may not be addressing the cause of poor positioning, which is often incorrect cueing, incorrect bracing, weakness in certain areas or a combination of all three.
Using pausing to correct these issues can work, frequently doesn’t, and in either case there are often more efficient approaches. If cueing is the issue, most commonly the problem begins before the bar is even unracked. Pausing will most likely appear to correct the issue by providing us with a stop during which we shift into better position before coming back up. This doesn’t fix the problem though. It just hides it. Setting up correctly from the beginning of the lift while the bar is still racked is a much more complete solution. Generally speaking if we have set up correctly before we even unrack, we will maintain that correct position throughout the lift. Another method of addressing this issue is squatting or benching off pins or chains set just below the stalling point where position is lost, although this is best used sparingly and only when cueing and bracing is already adequate. The reason these are better than pausing in most instances is that you set up under bar in the bottom position - so there is not really a descent and then a stop. You have to set up in the correct position to move the bar in the first place anyway. In most cases though, simply using correct cueing and bracing combined with improved strength in the lacking areas will do the job without having to resort to messing around setting up pins and chains.
If the issue is incorrect bracing (which will apply more to the squat, while in bench correct cueing is often the major contributor), learning to brace correctly will solve the problem. While pausing may indeed allow us to learn how to brace at the bottom and coming back up, it does nothing to teach us how to brace coming down. If we brace correctly from the get go, the entire problem disappears.
Lastly, if the issue is weakness in certain areas pausing is one of the least preferable means of addressing it. Let us suppose we pitch forward coming out of the hole. Assuming our cueing and bracing is correct, this means we have some weaknesses in our abs and back, and possibly our hamstrings. We can correct this by training the muscles involved. Not only is this effective, but training our lats, rhomboids, erectors, abs and hamstrings directly will place less fatigue on us and is less risky than pausing; it will also greatly benefit our bench press and deadlift.
When it comes to some supplemental exercises, mostly those that are more dissimilar to the main lifts, pausing can arguably be used a little more frequently but still with caution bearing in mind the injury risk. For example, front squats paused in the hole can be a very effective supplemental exercise for deadlifts in less experienced lifters. For one, the limiting factor will be how much weight the upper back can hold - this effectively guarantees that weights used will not be such to place undue strain on the lower back, hips and legs. The muscles doing the work - quads moving, lower, middle and upper back and abs stabilising - are those used to provide explosive drive off the floor when deadlifting. In this case, a similar training effect to deadlifting is derived using significantly lighter loads. A similar scenario is the floor press, where by necessity we pause at the bottom to ensure both arms are touching the floor. Here, the limited ROM safeguards the shoulder and pec muscles. It also trains the part of the bench press after leg drive has let us push the bar off our chests. Pausing at the bottom of the floor press simulates a stall, and lets us practice accelerating through it - but the exercise is sufficiently different to the bench press that it is not training us to be slow benchers. It also forces us to focus on correct shoulder and lat cueing because we don’t have the option of pushing ourselves into position with our legs. The incline press is the polar opposite, because the position makes engaging our lats harder. So we would never pause this, as it would put significant strain on our pecs and shoulders. I think it’s worth mentioning the Spoto press as well, because it looks paused but isn’t really. You can pause it, in which case the caveats of training to stop and be slow come into play. Or you can treat it as you do bench, where you touch your chest and come up - the touch is just enough to not bounce, except with Spoto presses the stop is an inch or so off your chest. You still have to cue correctly to stay in position, because there is nothing else to support the bar at the point of stopping, so you need to be locked in tight to be able to reverse direction explosively.