Validity and reliability of single and multiplanar hip strength measurements

Hip muscle weakness is a risk factor for many musculoskeletal injuries to the hip and groin region. Instruments used to measure hip muscle strength are designed to assess muscle actions in a single plane, which is not consistent with the multiplanar line of action of many hip muscles. This study aimed to assess validity and reliability of single and multiplanar hip strength measurements acquired with a custom-made rig. Results demonstrate moderate to excellent reliability, suggesting this rig can adequately measure multiplanar hip muscle strength, which may have important implications for studies of populations with hip pathology.