contractions/shortening and lengthening of muscles

[Andrew Graham]

My mind isn't made up....i'm just waiting for someone to logically answer the question "How can the tricep be concentrically contracting in an eccentric bicep curl if there is no load on the tricep!???" I will agree it's getting shorter....but there is no motorneuron going to the muscle to actively shorten it is there!?

 

So is there a term that relates to a loaded concentric contraction and a loaded eccentric contraction or should i say that when descending into a squat the proximal hip flexors are concentrically contracting but they aren't actively firing!?

 

This is where i'm confused.....so sorry if you think i'm wasting your time but isn't that what this forum is for!??....to answer peoples questions and help them??

[Chris Hobbs]

You seem fixated on the active flexion aspect of the hip flexors - specifically the psoas. Seeing as how the hip flexors serve multiple functions perhaps you should look into those other aspects to better understand their role during a squat and how they might contract to fulfill those other roles and not be responsible for the descending motion that takes place? Your claim that they don't need to contract says you don't quite understand that aspect.

 

When trainers speak about pulling yourself into the bottom position it is a cue meant to elicit a feeling in the trainee, not an anotomical observance specific to a certain muscle.

 

- Chris

[Andrew Graham]

Ok thanks for your reply Chris.

 

I have re-thought my question about this whole topic and to be honest it's very simple now. I think the way a phrased the question before just confused people to what i meant.

 

So here goes: I understand that the proximal end of the hip flexors are contracting during the descending process of the squat.

 

But what i don't understand is how they can be CONCENTRICALLY CONTRACTING because a concentric contraction is defined as "A muscle shortening at a greater force than the resistive load". and since there is NO LOAD on the proximal hip flexors (i'm not talking about the psoas..i understand what that does..i'm talking about the muscles that stay relaxed and floppy as you descend...i think recfem, sartorius and TFL) how can this be so?

 

So i agree they contract and take up their slack as you descend, my question is: WOULD THIS NON LOADED CONTRACTION STILL BE CALLED A CONCENTRIC CONTRACTION???

 

Thanks

[Andrew Graham]

Ok ladies and gentlemen

 

i have found the answer and i now understand what you were all getting at!

 

Thank you for all your time in trying to help me, i emailed Dr.Osar and he explained the science behind what i really needed to know

 

cheers all

 

sorry for goin on!!

[Chris Hobbs]

Perhaps share the response for reference sake so that others may benefit?

 

- Chris