Application of the Sit-to-Stand Movement for the Early Assessment of Functional Deficits in Patients Who Underwent Anterior Cruciate Ligament Reconstruction

Objective The aims of this study were to identify and quantify functional deficits between the involved and the uninvolved limb as early as 1 mo after ACL reconstruction by means of a sit-to-stand movement on two force platforms. Design Ground reaction forces were measured in 73 patients who underwent ACL reconstruction, 47 with patellar tendon autograft and 26 with hamstring tendon autograft (ACL-H), and in 22 controls, who stood up from a seat as fast as possible. Side-to-side limb symmetry index (LSI) was calculated for peak force and rate of force development. Results The LSI of vertical peak force was 59% in the patellar tendon autograft group and 68% in the ACL-H group, which were both lower than the 95% LSI of the controls (P < 0.001). The LSI of rate of force development was 27% in the patellar tendon autograft group and 48% in the ACL-H group, which were both lower than the 97% LSI of the controls (P < 0.001). After 2 mos, only in the ACL-H group, the LSI of both vertical peak force and rate of force development reached 88% and 80%, respectively, thus approaching the 96% and 92% LSI of the controls. Conclusions Sit-to-stand is effective for measuring functional deficits as early as 1 mo after ACL reconstruction. After 2 mos from surgery, the ACL-H group but not the patellar tendon autograft group approached the LSI of the control group, which may be attributed to differences in the graft.