Board Thread:Episode Discussions/@comment-25319479-20180719110008/@comment-36342497-20180727030950

UltimaDude wrote: Hinata didn't use Lightning Release for her Lion Fist. Even if she did how does that prove that she has an affinity for Lightning Release?

In the anime after she found out Naruto invented the Wind Release Rasenshuriken she starts developing her own technique with the help of neji. And since naruto uses his affinity for wind, it only makes sense for hinata to use her affinity, which for lightning. We see that the lion fists emit lightning, so I'm pretty confident about this.