PFP	Patellofemoral Pain
QoL	Quality of Life
KPS	Kujala Patellofemoral Score
FKIS	Fulkerson Knee Instability Scale
KOOS-PF	Knee injury and Osteoarthritis Outcome Score for Patellofemoral pain and osteoarthritis
KQoL-26	Knee Quality of Life 26-item questionnaire
COSMIN	Consensus-based Standards for the selection of health Measurement Instruments
PROMs	Patient-reported outcome measures
GRRAS	Guidelines for Reporting Reliability and Agreement Studies
SF-12	12-item Short Form health survey
KOOS	Knee injury and Osteoarthritis Outcome Score
SF-12-PCS	12-item Short Form health survey Physical Component Summary
SF-12-MCS	12-item Short Form health survey Mental Component Summary
BMI	Body Mass Index
SEM	Standard Error of the Mean
SDC	Smallest Detectable Change
KMO	Kaiser–Meyer–Olkin
ICC	Intraclass Correlation Coefficient