Abstract

In this study 114 female and male subjects underwent a 20-second statodynamic single leg stance (with each leg) on a 40x60 cm AMTI force plate to find out to which extend a force plate can be used to quantify neuromuscular deficits resulting in instabilities of the lower limb and balance problems. 83 subjects with an ACL lesion were tested 6 to 8 weeks post surgery. The data of 31 persons without an ACL lesion was collected to see whether they performed significantly different with each leg. Three different parameters were taken into account in the analysis of the data: the deviation amplitude of the centre of pressure (COP) [Newton], the changes of the COP in the vertical direction [Newton] and the reaction on sways of the COP [Seconds]. The results suggest the deviations of the COP in medio-lateral and anterior-posterior as well as the difference between maximal and minimal force in vertical direction as predicative parameters concerning the instability of the knee joint respectively neuromuscular deficits. The deviation in the medio-lateral direction is the most obvious parameter to show lateral instabilities, it was also proved that especially this medio-lateral deviation can be used to evaluate differences between the injured and non-injured leg of a patient. The controlling group showed no significant differences between each leg. The study describes the force as a suitable device for measuring uncertainties in balance which are caused by neuromuscular deficits. Verf.-Referat