Reproducibility of Sagittal Plane Knee Translation During Isokinetic Exercises

Abstract

-------------------. ------------------The reproducibility of sagittal plane knee translation during isokinetic exercises was measured in 10 healthy subjects. At eight different test occasions including two examiners. sagittal plane knee translation of both knees was measured with the CA-4000 system (Orthopaedic System Inc., CA) during maximum muscle forces on the Biodex machine (Biodex Medical Systems Inc.. Shirley. NY) at an angular velocity of 60 deglsec. Moderate correlations were found between the majority of the test occasions. with no differences between knees or examiners, but a high variability of sagittal plane translation was found in the individual subject (coefficient of variation [CVl. 6-22%). Higher correlations were found for total translation values than for left-right knee differences. No significant within-day, day-to-day, week-to-week. and between-examiner differences were observed. but a significant change in sagittal plane translation was noted between two tests immediately following each other, the second showing an increase in sagittal plane knee translation despite a similar muscle work at both tests. The amount of total muscle work varied greatly (CV 33%) in the total group, but little in the individual subject (CV 4-10%). Consequently, a moderate positive correlation was found between the total muscle work and sagittal plane knee translation in the whole group, but only weak or no correlations in the individual subject.