I had two herniated disks (T2/4) and one with a small fracture (T3). Clenching my jaw at night was leading to my SCM being tightened and applying pressure to the herniations, which was then causing imbalances in my upper back (which lead to the body correcting posture all the way down to your feet in a zig-zag manner) and also from my shoulder down to the wrist.

Mouth guard helps prevent too much pressure being applied to the neck, which gives pain relief all over.

As for soles, I had one foot that was facing outward while walking, which was identified by a physio to be due to hamstring tightness. But why is the hamstring tight? Automatic posture correction by my body! Since getting mouth guards, I've also been enjoying shoes with wide toeboxes and no rise too, which helped me correct my gait and reduce the impact on my hip.

That is incredibly interesting. I have a combination of flat feet and clenching my jaw, with a few posture issues and back/neck pain. So this gives me some insights to talk to my physio about - thanks for sharing!