Isokinetic assessment of the flexor-extensor balance of the knee in athletes with total rupture of the anterior cruciate ligament.

The purpose of this study was to assess the flexor-extensor group of muscles of the knee in young athletes diagnosed with a total rupture of the anterior cruciate ligament (ACL). Eighteen knees of 18 athletes (14 men and 4 women) with an average age of 21.6 years (range 16-32 years) were assessed with a Cybex 6000 model isokinetic apparatus. The average internal between occurrence of the injury and assessment was 10.2 months (range 2-48 months). There was an associated meniscal injury in eight of the knees. Athletes with any other kind of associated injury, limitation, or blockage of the movement of the joint, significant pain during the exam, or interval between injury and exam of less than two months were excluded from the study. The parameters studied were the peak torque-velocity and flexor-extensor relationships at the constant angular velocities of 60 degrees/sec and 240 degrees/sec. Previous warming-up was done by means of an ergometric bicycle and adaptation with 3 submaximal repetitions. The contra-lateral side, which presented no injury, was used as control. Peak torque (PT) at the constant velocity of 60 degrees/sec was greater than that at 240 degrees/sec for knees with and without injuries. However, there was no significant difference between the injured and uninjured sides at 60 degrees/sec or at 240 degrees/sec. The average value for the flexor-extensor relationship at 60 degrees/sec on the injured was 60% ((6), compared to 57% ((10) on the contra-lateral side. At 240 degrees/sec, the average value was 75% ((10) on the injured side, and 65% ((12) on the contra-lateral side. In conclusion, despite the complete rupture of the ACL of one knee, the average values for the flexor-extensor relationship were similar on the injured and uninjured sides at the velocity of 60 degrees/sec. As the velocity increased, an increase in the values for the flexor-extensor relationship of the knee also occurred, indicating a tendency of the performance of the flexor muscle group to approach that of the extensor muscle group, and this tendency was more pronounced on the side of the injury.

[Evaluation of isokinetic trunk flexion and extension in normal sportsman and sedentary people]. / Avaliação do torque isocinético flexor e extensor do tronco em atletas e sedentários normais.

It was studied two groups: Group 1: 13 male voluntaries, competition sportsman, mean age: 25 +/- 2.1 years (18-30): Group 2: 17 male voluntaries, sedentary, mean age: 31.2 years (23-46). All the voluntaries was evaluated by the CYBEX 6000, TEF (trunk flexion extension) module. The parameters analyzed were: peak torque, total work and average power (absolute values and corrected by the body weight) and the flexion/extension relation. All the tests were performed at the speed of 60 and 120 degrees per second. The peak torque absolute values at 60 and 120 degrees were higher in Group 1 than Group 2 (p < 0.05), in flexion and extension movement. At the corrected date by the body weight, this relation remained the same, at 60 degrees, for flexion and extension and for extension at 120 degrees (p < 0.05), but the flexion at 120 degrees is not different in both groups. The peak torque angle is the same for extensor tests at both speed, but is different for the flexor test, at 60 degrees. The total work performed was better in the Group 1 at 60 degrees during the flexion (p < 0.05) and during the extension in both tested speed. At the corrected values the work is the same at flexion and at extension is higher only at 120 degrees (p < 0.05). At the average power of flexion movement there is a difference at the absolute values, that was not seen at the body weight corrected date. The difference between average power of the extension, in both speeds was significant at 60 and 120 degrees. The relation between flexor and extensor: Group 1: peak torque 80% at 60 degrees, total work and average power is nearly 100%; Group 2: peak torque, total work and average power is closed to 100%, at 60 degrees. The flexor muscles values are light higher than the extensor muscles, that means the abdominal muscles are stronger than the spine erector muscles. At 120 degrees this tendency is more clear and the relation is 120-125% and at the sedentary group this relation is higher: 150-165%.