Locking limbs: when to do and when to avoid?

As far as I know (but I am a beginner!), for many exercises, both with body weight and with weights, it is recommended not too fully lock limbs when performing reps. Examples are push ups pull ups, shoulder presses... I suppose this is to protect the joint  - against what exactly?

On the other hand, it seems to me that some gymnastic movement, for example handstands, are to be performed with fully locked limbs, and the load is considerable.

So, I would like to understand when is it bad to lock limbs and when it is not. Is the point that it is wrong doing it when you are bending and extending multiple times, like in push ups, but it is fine when holding, like in handstands, or is it something else?

You should be locking out at the bottom of pull-ups, top of Push-Ups/Dips, etc. Its not dangerous, and you will be fine. Most of the people who advocate the don't lock out, have terrible form anyway, and are getting injured because of their terrible form and mobility deficits.

grayhawk said:

As far as I know (but I am a beginner!), for many exercises, both with body weight and with weights, it is recommended not too fully lock limbs when performing reps. Examples are push ups pull ups, shoulder presses... I suppose this is to protect the joint  - against what exactly?

This can be heard by more and more people which are doing bodybuilding.

When elbows are locked for exemple in planche large amount of force is placed on tendons (brachialis and biceps tendons in this case) to keep joint straight without snaping. When somebody who is not used to locking elbows tries to lock while holding some weight he will experiance discomfort in joint/tendon area becouse his tendons are not strong enough to hold it. And then usualy what happens is that this person ignores that discomfort over and over again untile he develop injury and then everybody is speeking around how he injured himself from locking elbows at end of each rep.

Locking in pushups and pullups puts minimum pressure on elbows and it is not dangerous, but when doing exercises like weighted dips be careful.

Dont lock elbows if your experiencing discomfort and pain and you will be fine.

Thank you for your explanations!