Isokinetic dynamometry and electromyographic activity (sEMG) after anterior cruciate ligament reconstruction using semitendinosus and gracilis tendon autografts

Abstract

Isokinetic dynamometry and electromyographic activity (sEMG) after anterior cruciate ligament reconstruction using semitendinosus and gracilis tendon autografts D. Mourauxa, P.-M. Dugaillya, E. Brassinnea and M. Vancabekeb Department of Physical Therapy and Rehabilitation, Erasmus Hospital, ULB, Brussels, Belgium Department of Orthopaedics Surgery, Brugmann Hospital, Brussels, Belgium Introduction: Quadriceps weakness after injury and reconstruction of anterior cruciate ligament (ACL) is well documented. This amyotrophy in the immediate postoperative period is related to several factors, such as decreased weight bearing, knee joint effusion, pain, harvesting of the tendon graft and neuromuscular factors [1]. The present study is designed to compare the short outcome of strength and EMG recruitment pattern of quadriceps and hamstring between 3 months postoperatively for an ACL reconstruction with hamstring tendon autografts fixed patients and a healthy control group. Methods: Thirteen healthy male students (mean age: 24 years, weight: 77 kg, height: 181 cm) participated in the study. They had no history of knee or hip injuries. They were compared to 19 patients (mean age: 31 years, weight: 80 kg, height: 180 cm) who had surgery for ACL reconstruction with hamstring tendon autografts precisely 3 months before these assessments. Patients were excluded if there were any other lesions in the same knee. In both groups the subjects were recreational athletes. All subjects were familiarized with isokinetic movements in concentric (CON) or ecTable 1 Mean ± standard deviation of quadriceps and hamstrings Peak Torque (PT). Comparison between control legs and UninvolvedInvolved legs. ∗Significant at p < 0.05 level Control Uninvolved Involved Quad PT Con 180◦/s 136 ± 23 125 ± 37 93 ± 28∗ Quad PT Con 60◦/s 193 ± 30 183 ± 30 118 ± 47∗ Ham PT Con 180◦/s 101 ± 16 89 ± 30∗ 85 ± 9∗ Ham PT Con 60◦/s 137 ± 18 118 ± 22∗ 101 ± 33∗ Ham PT Ecc 30◦/s 178 ± 13 146 ± 20∗ 113 ± 10∗ centric (ECC) contraction. The tests were performed with a CYBEX NORM consisting in 3 maximal dynamic contractions at 180◦/s and 60◦/s in CON (for both flexor and quadriceps muscles) and at 30◦/s in ECC (for flexor). During these tests, the sEMG activity was recorded from the vastus lateralis (VL), the vastus medialis (VM) the rectus femoris (RF) and the mass of the hamstring by the Noraxon Myosystem 2000. The exercices were performed at a range of motion from 0◦ to 105◦. All electrical activities were expressed in microvolt (μV). Influence of independent variables was analysed using multivariate analysis of variance