Validity and reliability of the movement ability measure: A self-report instrument proposed for assessing movement across diagnoses and ability levels

Abstract

Background and Purpose: Physical therapists lack instruments that assess movement across diagnoses and ability levels while focusing on physical therapy-specific outcomes. This article describes the creation of a Movement Ability Measure (MAM) and initial evidence of validity and reliability. Subjects: More than 300 adult volunteers with various movement levels completed the 24-item questionnaire. Methods: Item response theory methods were used to create the MAM and gather evidence of content and construct validity, test-retest and other types of reliability, and concurrent validity with the California Functional Evaluation instrument and self-acknowledgement of movement problems. Results: The intraclass correlation coefficient for test-retest reliability was .92. Person separation reliability was .98. Correlation (r) with the California Functional Evaluation instrument was .76. Respondents who denied having movement problems perceived a significantly higher level of movement ability than those who claimed to have a little, some, or a lot of movement problems in the preceding week. Discussion and Conclusion: The MAM shows promise for documenting perceived movement ability across ability levels and diagnoses. © 2007 American Physical Therapy Association.