Novel Method for Evaluation of Hindfoot Alignment in Weight-bearing Position Using Laser Beam

[Purpose] It is clinically important to accurately evaluate the alignment of hindfoot alignment from the body surface in weight-bearing position. In general, measurement is carried out using a goniometer, but the measurement with goniometer requires experience, and the reliability in this measurement is also in question. Therefore, it is necessary to establish a clinical measurement method to replace the goniometer. As a solution, we devised a hindfoot alignment measurement method with laser beam (HAML), which measures hindfoot alignment along the body surface using a laser beam. This study aimed to study the correlation between the measurement result along the body surface with laser or goniometer and that of radiography with regard to hindfoot alignment. [Subjects and Methods] Subjects included 23 individuals with knee osteoarthritis. Their hindfoot alignment using radiography and goniometry were measured. The correlation between the measurement result along the body surface with or without laser and radiography was investigated. [Results] The correlation between HAML and radiography was better than that between HAML and goniometry. [Conclusion] The correlation between radiography and HAML for measuring hindfoot alignment was good. This finding implies that HAML can be used as a screening test or epidemiological survey in regional medicine.