There are multiple definitions:

1. prolactin-inhibiting factor(English)

   • PIH

2. proteolysis-inducing factor(English)

3. paired impulse function(English)

   • IPI, PP, RIT

4. potential impact fraction(English)

   • PAR

5. prophylactic internal fixation(English)

   • method of choice for managing the radial osteocutaneous donor site
   • Surgery
   • https://doi.org…oms.2006.08.025

6. postural instability with falling(English)

   • one component of postural instability and gait difficulty
   • APOE, FOG, MMSE, PD, PIGD, UPDRS
   • Parkinson, Aging, Musculoskeletal system
   • https://doi.org…nnp.2010.222042