Complex sentence: Custom orthotic devices have been demonstrated as an effective method to reduce plantar fasciitis pain for up to 12 weeks; the long-term effectiveness of custom orthotics for plantar fasciitis pain reduction requires additional study.
Split into simpler sentences: Custom orthotic devices have been demonstrated as an effective method to reduce plantar fasciitis pain for up to 12 weeks. The long-term effectiveness of custom orthotics for plantar fasciitis pain reduction requires additional study.