Why is it okay to arch that hard during squats, but it is bad for you back to hyperextend when doing back extensions? it seems like your back is in the same position.
[quote]DjSm28 wrote:
Why is it okay to arch that hard during squats, but it is bad for you back to hyperextend when doing back extensions? it seems like your back is in the same position. [/quote]
The back may look like it’s in the same position, but consider how the load (the weight itself) is distributed.
In the squat, the weight is distributed across the entire shoulder girdle/upper back, the lats, down through spinal erectors, to the glutes, etc. An arched back is also needed to keep the load over your base/center of gravity.
The back extension, where the load is usually placed across the upper back, has less muscles contributing to the support and stability. It also places the vertebrae themselves in a more potentially-dangerous position. Also, the load in this position is much farther from your center of gravity, which further increases the stress (holding plates to the chest or a bar/db in the “deadlift” position could be a safer alternative).
Thanks. Just making sure. I appreciate it.
However, not i’m thinking, why can you arch like that during deadlifts and not back extensions? Isn’t it kind of the same there?
[quote]DjSm28 wrote:
However, not i’m thinking, why can you arch like that during deadlifts and not back extensions? Isn’t it kind of the same there?[/quote]
Nope. The same original reasoning applies here.
Why is it considered good, safe technique to keep the bar closer to your shins, rather than swaying farther out in front of your body? Because carrying the load closer to your center of gravity reduces the stress on the individual vertebrae by allowing you to incorporate many more muscles (compared to an extension) into the lift.
Round-back deadlifting (the essential opposite of an arched-back) is when most deadlift injuries occur… because it exposes the verterbrae to excessive stress.
The back should have a natural arch when squatting or deadlifting, and should not be hyperextended. Some people have to focus on trying to arch the back in order to counter the tendency to round the lower back during squats and deads, but the result should still be a neutral spine, not a hyperextended one.