Subject: How does sliding filament muscle contraction really work?

I understand how the process is supposed to work, yet if the myosin 
filaments on one side of a z-disc are ratcheting the actin filaments 
and shortening them, it seems to me that the process would cancel out 
and no contraction would occur.  One side seems to be pulling against 
the other and no net gain could result.  Possibly this process is just 
accepted to work, yet by examination of a sliding filament diagram it 
illustrates my question as to how it doesn't act like a tug of war.  
please help!!
thank you 
sincerely
Jay Smith

Re: How does sliding filament muscle contraction really work?