male staffie not behaving on lead when going for walk

Hi
My male staffie Harvey, who is just on 6 years old all of a sudden will not walk on his lead properly when we take him for a walk....

at first I thought it was because he was trying to show the two girl staffies he is still the "boss" on walks but we tried again yesterday with just him and he almost gets stupid on the lead and wants to just take off that he ends up pulling so hard that he runs on just his back legs....

please can someone help with some advise on how to re-train him at home so he can eventually go for a walk

many thanks
kim

How often does he go out, and what sort of walks does he get? ie, length, places, variations.

we used to take them at least twice a week..... but in the last two months Harvey has really been misbehaving so haven't been taking them until we tried again yesterday..... we either go around the block with them or for longer walks of about two and half kilometres or we go to the beach(he has even become a naughty at the beach where he just wants to run and not listen to instructions)

It sounds like he needs more exercise as twice a week isn't enough. Misty can pull terribly so she is walked on a harness and when she pulls I stop. She then comes back to me and we start walking again, if she pulls then again I stop completley. It does take time. Have you tried clicker training?

Twice a week is nowhere near enough, unless he's getting other exercise.

A Stafford if 6 years old should be getting walked at least twice a day, fir at least half an hour each walk. 

He's basically going stir crazy. ( https://www.urbandictionary.com/define.php?term=stir-crazy)