Arm Locking

Please advise:-
 
It was arm day on friday and i became very frustrated when i couldn't lift hardly any weight with my left arm when doing dumbell curls?
 
Its very strange and hard to explain but at the bottom of the curl motion i cannot even begin to lift the weight and its as if my elbow is locked? my bicep does not strain and i cant seem to move the dumbell upward at all?
 
If i start the motion at the top then as soon as my arm returns to the lower position this occurs again?
 
Can someone please help as its very frustrating and my arms are going to grow slower than the rest of me if i cant work them out!!!!

Dave, i dont think this is an injury problem per se. It could be but from what you say its probably due to using a weight thats too heavy for you to be doing STRICT DB curls. You would probably get more responses if you posted this in the training forum.
 
But id say, dont lock your elbow. Go close to locking to get the full range of movement, but dont lock. Locking your elbow puts you in a 'dead; position which is the equvalent of starting the bench press with the bar already on your chest. Not quite the same but you can see what i mean by dead position.
 
Locking also puts you at a greater risk of injury. Tendonitis can commonly occuring in the elbow from 'locking' exercises - such as military barbell press at the top of the motion, lying EZ bar extension for triceps, biceps curls etc.
 
Like i said, try post this in the training forum. You may get more feedback there.

Cheerz Lynx