I hurt my hip flexor doing an ATW before training about 6 weeks ago. It felt like a 'pop' in the tendon/muscle, and it hurt a bit. Now, when I do freestyle tricks such as around the world or a variant of it, it makes the same popping pain after a while (say, the fifth time I try and do one the injury occurs). It doesn't limit my on-field performance at all, it's just when I try these tricks that involve rapidly spinning my leg (ATW) that risks the pain in my leg, and as mentioned, usually after a few attempts. Advice?