I don't mind chiming in here with some pretty general info (btw, I'm a podiatrist).
A stiff big toe knuckle, often but not always the result of osteoarthritis (OA), is called hallux limitus/rigidus (hallux = big toe).
When you toe-off (propulsion), that big toe knuckle has to bend so you can transfer your weight to the other foot. Without it, your gait has to change - you compensate by either out-toeing and rolling off the inside of your foot so the big toe doesn't have to bend; or you toe-off through the lesser toes and reduce the force going through that joint as it bends.
Most shoes are designed to allow the forefoot to bend - it's a normal and efficient way to walk, and the way the foot was designed to function. But it doesn't help if you have painful OA in that joint. So many get relief with shoes that have one or more of the following features:
- Relatively stiff sole at the forefoot - I say relatively because this is not a desirable feature for a normally-functioning and asymptomatic big toe knuckle, so you'll find them hard to come by. Basically it doesn't let the forefoot bend as much/as easy.
- Rockersole - A rounded sole so you can transfer weight from heel to toe and over to the opposite leg by rolling through, all while your foot sits flat in the shoe.
- Thicker sole (usually rockersoles are thicker, and the thickness generally means stiffer, but not always)
Or you can see a podiatrist (at least in my part of the world - Australia) and potentially get a carbon fibre plate fitted to the shoe which doesn't allow either just the big toe or the whole forefoot, to bend. This forces you to compensate in one way or another. This sometimes goes smoothly but sometimes aggravates other problems because of the compensation.
Final piece of advice: Some people have plenty of range in that big toe knuckle but because of how their feet work, that range is unavailable when they walk (functional hallux limitus). There's no OA but it can be painful. This often requires foot orthoses with specific design features to facilitate the function of this joint.
I do hope I haven't overstepped the mark. Please take this as general advice and seek the professional opinion of a podiatrist who can look at your foot structure and function to tailor advice and treatment recommendations specific to your needs.
All the best
@chinalil!