A lacrosse ball is great for getting into places that a foam roller can't. I've recently been using one for just behind my elbow on the triceps and forearms (elbow issues). I set it on a bench, kneel in front of it and let the weight of my arm drive it in and slowly roll it around until things start to release. You can do this for 5-10 minutes or just a couple. I don't suggest doing it pre-workout unless they're really stiff and if you do, be gentle haha (I prefer dynamic stretching (non-static) before and rolling/static stretching afterward, but everyone is different). These lacrosse balls, yellow balls etcs. can get into places in your hips that a foam roller can't, they're brutal. I'm huge on foam rolling, so definitely biased here. It can help with a lot of things, especially fascia work if massage therapy isn't an option.