Are lunges healthier for the joints than leg machines like leg extensions?

I'd say lunges, because they're movements we perform every day. They're therefore natural. The movements on leg machines such as leg extension/leg curl or adduction/abduction machine never actually occur in everyday life and are a completely unnatural movement for the hips. Is my line of thought correct? I thank you.

Pain in the right groin when abducting and adducting the leg?

I've had a cracking sensation and slight pain there for at least three weeks. Every time I try to work out on the abduction and adduction machine, it hurts a lot, which is why I haven't been able to do it for a while. What could be causing this pain? It's certainly not muscle soreness….