Use it or lose it. You are looking after yourself, and no doubt the intentions of these lads is the same. But you have to constantly build, maintain and build stability with abd for Olympic lifting or OH Squats.
Stability & mobility, especially for the modern office worker, is something you have to battle forever. Bottom line. Every day you go in and sit down you are messing that up.
Add in putting heavy stuff over your head and you need an even higher level of it. I have a few Crossfitters with me. 2 in particular are animals. Clean & Press over their BW when they walked in. But neither of them could hold a Back Extension (off a glute ham machine) for a minute. In fact one of them stopped in pain after 20 secs the first day. That would indicated to me they are not (and visually this was apparent) using their spine correctly at all. They were basically grinding it out thru speed, strong shoulders & hips but not using their backs in between to stabilize at all.
See can you do a hanging Back ext for 1 min + and close to a full wall slide (google them, mike boyle probably has best wall slides). 2 indications of true stability & mobility above the hips for Overhead anything (snatch or clean of OH Squats). Below the hips then is all about pelvic tilt. If you have whats called butt wink, a serious twist of the pelvis at bottom part of the squat then you are doing untold damage to Lumbar region, L4&5 most likely. This comes from sitting mostly. Hammys get tight, hip flexors get tight, glutes get weak. This causes the pelvis to be literally oulled either forwards or backwards anywhere up to 50 degrees in cases. This is normally the reason for low back pain in office workers. Its also one of the reasons for hamstring tears or tightness in amateur athletes who also sit at a desk.
This is the important part. Lets say you do a 60KG Clean & Press x3-5 reps. Add the 60 + maybe 50% your own body weight. Lets say 100KG in total. Thats the dead weight coming down on a lumbar region with an added shearing of the vertabrae. You roll over the L4&5 in particular with that. Now remember its a power exercise so its happening fast. Mass x Speed = Force. The downward force at speed is actually going to be anywhere between 2 & 6 times the weight going down on your spine. So probably 200-300 KG’s of force down thru the spine. X 3-5 reps. So within 45 secs you put around 1000 KG thru your spine. Are you ready for that? And thats not ever considering the knees and if you have knee valgus.
Now that takes serious spinal stability and a near perfect technique. The Chinese are coaching kids from age of 6 now to develop this for the high end Olympics. Bulgarians trained 6 times a day to become the best. 4 of those sessions were technique and stability based. 2 lifting.
Being able to put the thing over your head is one thing. And that can be restricted by mobility in thiracic or hip or even ankle regions. However having the actual stability for it is another ball game. I have probably 2 guys who i would consider doing Olympic lifting with. They are both with me over a year. And its only consider. There is no real need for it. Not for sport or life. But they are fun, technical and challenging. They have probably done over 100 stability sessions with me, and some homework too specific to them.
The first thing i will do then is break the moves down into all the different sections and oractice them. 1st pull, 2nd pull, transition, rack, catch, hang, squat, OH Squat etc etc
These are the things that Crossfit does not, generally, consider.