부산대학교 도서관

Recurrance of injuries are prevalent in athletes that have undergone ACL reconstruction which partly can be attributed to weakening and the reduction of neuromuscular control of the hamstrings and the quadriceps. When using autograft for the ACL reconstruction, the tissue is mainly harvested either from the hamstring tendon or from the patellar tendon which can have an effect of the overall biomechanics and load transfer integrity of the knee joint. In the presented study a 30s continuous single leg jump was carried out by subjects from three cohorts: a healthy control, patients that were recovering after ACL reconstruction using both hamstring and patellar tendon autograft. EMG measurements were taken of six muscles during the jump sequence: 1) Vastus Lateralis, 2) Vastus Medialis, 3) Biceps Femoris 4) Tensor Fascia Latae, 5) Semitendinousus and 6) Gluteus Medius. An acceleorometer located at the inferior lumbar region was synchronized with the EMG measurements to capture the events of push off and landing. The jump cycle was normalized from push off to the next push off as can be seen in the figure and the EMG signals rectified and processed using a bandpass filter and RMS and finally fitted to each normalized jump cycle. The jump sequence was divided into three parts containing equal number of jumps. The average EMG values were analyzed between the first third and the final third of the jump sequence. The results demonstrated that there is a temporal shift in the peak activation levels of the quadriceps muscles. Significant shift in peak activation is seen in Control group for both quadriceps and hamstring, and in Injured HS group for quadriceps muscle and Healthy BTB for lateral hamstring muscle and lower peak activation levels of the vastus lateralis (p<0.001) and vastus medialis (p<0.001) and lateral hamstrings (p<0.001) in the injured compared to healthy legs. [ABSTRACT FROM AUTHOR]