Assume that while praying namaz, when i recite 'same Allaho leman hamedah' after getting up from ruku, I bend for sajdah while my recitation of 'same allaho..' is still not completed. I complete that recitation after reaching almost to sajdah ie: i continue the recitation while I bent for sajdah. So my question is that such namaz is invalid? thank you.

While you are saying same Allaho
You must be standing and that qyam is must movement is not allowed if you are bending then Namaz is batil