He is getting the start of PF. The “root” cause is the tight calf muscle. He will need a “slant board” to create a negative heel. He also “may” need a Morton's Toe extension for that first metatarsal head. He should use a thera band or old bike inner tube for dorsiflexion and plantar flexion. Let him try a couple of barefoot grass runs to see how it feels. A little at a time.