A pilot study was carried out to evaluate validity and reproducibility of a food frequency questionnaire (FFQ), which was designed to be used in a prospective cohort study in a population at high risk ...

Background: Self-report questionnaires play an important role as outcome measures in shoulder research. Having an estimate of the measurement error of these ...

The purpose of this study was to determine the validity and reliability of the Persian version of the Vividness of the Movement Imagery Questionnaire 2 (VMIQ-2). In the first stage validity and ...

Background Novel treatment interventions are advancing rapidly in the management of hip and groin disability in the physically active young to middle-aged population. Objective To recommend the most ...

There is a distinction that one learns about on the first day of a course in psychological research methods. It is the difference between internal and external validity. Internal validity is ...