Reliability of the Center of Pressure Parameters after ACL Reconstruction Surgery

The elicited parameters from the center of pressure (COP) of patients after surgery of the anterior cruciate ligament are proper indications for estimating balance after surgery and rehabilitation. Thus, making sure about repeatability of COP parameters which can determine the knee joint after the knee reconstruction surgery is very important. This study measures repeatability rate of some COP parameters after reconstructing anterior cruciate ligament in various positions. In this study, 15 athlete men (mean age: 27±5) after 4-6 months since repair of their anterior cruciate ligament were included; they have been selected through simple non-probability sampling method. The study was conducted in biomechanics lab of Tarbiat Modares University in 2010. Assessment of balance was done with open/closed eyes, with/without foam using force platform in two sessions with 48 hours interval. The external-internal amplitude (0.86), external-internal standard deviation (0.86), phase plane (0.82) and area oscillation (0.81) were among parameters which showed the most repeatability. The average oscillation of anterior - posterior frequency (0.6) showed the lowest repeatability. A number of parameters caused by oscillation of COP show high rate of repeatability after reconstructing anterior cruciate ligament which can be used as an assessment of patients condition after reconstruction of the anterior cruciate ligament.