I’ve found tools can be very controversal. Even if they aren’t detrimental by nature. One of those tools is the dreaded flexi-leash. Everyone has encountered them, some have had great experiences with them while others absolutely hate them. I’m middle of the road. I’ve had dogs come flying around a corner in a store and ambush my dogs. I’ve had dogs block bike trails while out for a ride with Dingo, and putting us at risk of a bad fight. I’ve also seen dogs in the middle of the road while their person blindly walks on the sidewalk texting. I’ve even seen dogs take off at a full-out run and yank the handle out of a person’s hand. But I’ve also seen them being used responsibly. There in is the underlying problem, most people don’t give a hoot if their dog could potentially end up dead cause they let is wander willy-nilly on a 15ft flexi.
Flexis can be great if you’re walking in a field, or even doing off leash prep, but on a train, sidewalk or other place where someone is at risk of being tripped is not a good idea.
The other thing I see commonly is flexileads use with a flat buckle collar or even choke chains. This is an awesome way to collapse a dogs trachea. Even if the dog is not pulling you, it’s pulling the leash. The reeling mechanism inside the handle creates tension for the dog to pull against. It’s been hypothesized that this can set loose leash walking back because you’re training your dog to pull you (The dog gets freedom for pulling.).
If you insist on using a flexi leash, use it responsibly or accept the responsibility of any injury resulting from having no control over your dog. I’d also recommend working on LLW before using a flexileash.