CORRELATION BETWEEN ECCENTRIC TRAINING AND FUNCTIONAL TESTS IN SUBJECTS WITH RECONSTRUCTED ACL

ABSTRACT Introduction: Eccentric training and jump tests are widely used to recover and measure deficits in knee strength and functionality after anterior cruciate ligament (ACL) reconstruction. Objective: To correlate knee extension and flexion torque generated by eccentric isokinetic training, with functional jump tests in subjects with reconstructed ACL. Method: Sixteen men with unilateral ACL reconstruction were assessed before and after 12 weeks of eccentric isokinetic training of knee flexors and extensors (3×10 MVC, 2x/week) at 30°/s for extension and flexion torque (isometric; concentric and eccentric at 30 and 120°/s) and functional jump tests (single, triple, cross and figure of 8). Inter- and intra-limb pre- and post-training mean peak torque (MPT), distance and jump test times were compared along with the correlations between these variables, considering P<0.05. Results: The affected limb (AL) showed significant gain of extension and flexion torque (P<0.01) in the different test categories and velocities evaluated. In the non-affected limb (NAL), this only occurred in the eccentric category (30 and 120°/s), in the extension (P<0.01) and flexion (P<0.05 and P<0.01) torques, respectively. In the jumps, there was an increase in distance (single and triple; P<0.05) and a decrease in time (crossed and figure of 8; P<0.01), however, MPT x Jump correlations were weak (r<0.3) in the pre and post-training period in both limbs. Conclusion: Despite the gain in knee extension and flexion torque and jumping performance, the expected correlation was not satisfactory, suggesting that knee functionality involves other variables inherent to motor control. Level of Evidence IV; Type of study: Case series.

摘要
引言：离心训练与跳跃测试被广泛应用于前交叉韧带（anterior cruciate ligament, ACL）重建术后膝关节力量与功能缺损的康复与评估。
目的：探讨前交叉韧带重建术后患者经离心等速训练产生的膝关节伸、屈力矩，与功能性跳跃测试结果之间的相关性。
方法：纳入16名单侧前交叉韧带重建术后男性受试者，在接受12周膝关节屈、伸肌离心等速训练（每组3组×10次最大自主收缩（maximum voluntary contraction, MVC），每周2次）前后，分别评估其膝关节伸、屈力矩的平均峰值扭矩（mean peak torque, MPT）以及功能性跳跃测试指标。其中，力矩测试涵盖等长、向心与离心模式，测试速度分别为30°/s和120°/s；训练速度为30°/s。功能性跳跃测试包括单腿跳、三次连续跳、交叉跳与8字跳。本研究比较训练前后肢体间与肢体内的平均峰值扭矩、跳跃距离与跳跃耗时，并分析上述变量间的相关性，检验水准设定为P<0.05。
结果：患侧肢体（affected limb, AL）在各测试类别与测试速度下的伸、屈力矩均获得显著提升（P<0.01）；健侧肢体（non-affected limb, NAL）仅在离心测试类别（30°/s与120°/s）下，伸肌力矩（P<0.01）与屈肌力矩（分别为P<0.05和P<0.01）出现显著提升。在跳跃测试中，单腿跳与三次连续跳的跳跃距离显著增加（P<0.05），交叉跳与8字跳的跳跃耗时显著缩短（P<0.01）；但训练前后双侧肢体的平均峰值扭矩与跳跃测试结果间的相关性均较弱（r<0.3）。
结论：尽管膝关节伸、屈力矩与跳跃表现均获得改善，但预期的相关性并未达到理想水平，提示膝关节功能还涉及运动控制相关的其他固有变量。
证据等级：IV级；研究类型：病例系列研究。