Reliability and validity of DPA-1 testing after anterior cruciate ligament reconstruction

There is a lack of equipment and methods for the reliable and valid measurements of human neuromuscular control. To overcome this limitation, an analyzer of dynamic parameters (DPA-1) of human hand and leg movements was constructed by Kaunas University of Technology and "Katra" engineers in collaboration with the Lithuanian Academy of Physical Education. The aim of the study was to determine the reliability and validity of the tests performed on the DPA-1 in healthy and injured subjects after the anterior cruciate ligament (ACL) reconstruction surgery. MATERIAL AND METHODS. The men who had undergone a unilateral ACL reconstruction (n=17, on the average 3.8 months [SD, 2.1] after the surgery) and healthy untrained men (n=17) performed the research protocol twice within 24 hours in between. Average reaction time, mean and maximal movement speed, time to reach maximal speed, and movement distance of the right and left feet for the patients and of the dominant foot for the healthy subjects using the DPA-1 as well as the scores of isokinetic muscle strength and self-assessment tests were registered. RESULTS. There was a significantly reduced concentric peak torque on the injured knee compared with the uninjured knee during knee extension, and the mean score of the Lysholm scale for the injured knee was 69.1 (SD, 13.7) (P<0.05, compared between legs). The test-retest reliability for all the DPA-1 tests varied from 0.68 to 0.94 (P<0.05). However, there were no significant differences in most variables measured by the DPA-1 between injured knee, uninjured knee, and control knee. CONCLUSIONS. The results revealed low validity of the DPA-1 tests for the evaluation of patients following ACL surgery, despite the reliability of these tests varied from moderate to very high.