Department of Radiation Sciences, Biomedical Engineering, Umeå University, Umeå, Sweden.
Department of Community Medicine and Rehabilitation, Physiotherapy, Umeå University, Umeå, Sweden.
PLoS One. 2019 Oct 31;14(10):e0224261. doi: 10.1371/journal.pone.0224261. eCollection 2019.
The purpose was to evaluate the dynamic knee control during a drop jump test following injury of the anterior cruciate ligament injury (ACL) using finite helical axes. Persons injured 17-28 years ago, treated with either physiotherapy (ACLPT, n = 23) or reconstruction and physiotherapy (ACLR, n = 28) and asymptomatic controls (CTRL, n = 22) performed a drop jump test, while kinematics were registered by motion capture. We analysed the Preparation phase (from maximal knee extension during flight until 50 ms post-touchdown) followed by an Action phase (until maximal knee flexion post-touchdown). Range of knee motion (RoM), and the length of each phase (Duration) were computed. The finite knee helical axis was analysed for momentary intervals of ~15° of knee motion by its intersection (ΔAP position) and inclination (ΔAP Inclination) with the knee's Anterior-Posterior (AP) axis. Static knee laxity (KT100) and self-reported knee function (Lysholm score) were also assessed. The results showed that both phases were shorter for the ACL groups compared to controls (CTRL-ACLR: Duration 35±8 ms, p = 0.000, CTRL-ACLPT: 33±9 ms, p = 0.000) and involved less knee flexion (CTRL-ACLR: RoM 6.6±1.9°, p = 0.002, CTRL-ACLR: 7.5 ±2.0°, p = 0.001). Low RoM and Duration correlated significantly with worse knee function according to Lysholm and higher knee laxity according to KT-1000. Three finite helical axes were analysed. The ΔAP position for the first axis was most anterior in ACLPT compared to ACLR (ΔAP position -1, ACLPT-ACLR: 13±3 mm, p = 0.004), with correlations to KT-1000 (rho 0.316, p = 0.008), while the ΔAP inclination for the third axis was smaller in the ACLPT group compared to controls (ΔAP inclination -3 ACLPT-CTRL: -13±5°, p = 0.004) and showed a significant side difference in ACL injured groups during Action (Injured-Non-injured: 8±2.7°, p = 0.006). Small ΔAP inclination -3 correlated with low Lysholm (rho 0.391, p = 0.002) and high KT-1000 (rho -0.450, p = 0.001). Conclusions Compensatory movement strategies seem to be used to protect the injured knee during landing. A decreased ΔAP inclination in injured knees during Action suggests that the dynamic knee control may remain compromised even long after injury.
目的是使用有限螺旋轴评估前交叉韧带损伤（ACL）后下落跳测试中的动态膝关节控制。17-28 年前受伤的患者，分别接受物理治疗（ACLPT，n=23）或重建和物理治疗（ACLR，n=28）和无症状对照组（CTRL，n=22）进行下落跳测试，同时通过运动捕捉记录运动学。我们分析了准备阶段（从飞行过程中的最大膝关节伸展到触地后 50 毫秒），然后是动作阶段（触地后最大膝关节屈曲）。计算膝关节运动范围（RoM）和每个阶段的持续时间（Duration）。通过其与膝关节前后（AP）轴的交点（ΔAP 位置）和倾斜度（ΔAP 倾斜度）来分析有限膝关节螺旋轴在约 15°膝关节运动的瞬间间隔。还评估了静态膝关节松弛度（KT100）和自我报告的膝关节功能（Lysholm 评分）。结果表明，与对照组相比，两个阶段的 ACL 组的持续时间更短（CTRL-ACLR：持续时间 35±8ms，p=0.000，CTRL-ACLPT：33±9ms，p=0.000），膝关节屈曲度更小（CTRL-ACLR：RoM 6.6±1.9°，p=0.002，CTRL-ACLR：7.5±2.0°，p=0.001）。低 RoM 和持续时间与 Lysholm 根据 KT-1000 评估的膝关节功能较差和膝关节松弛度较高呈显著相关。分析了三个有限的螺旋轴。与 ACLR 相比，ACLPT 中第一轴的 ΔAP 位置最靠前（ΔAP 位置-1，ACLPT-ACLR：13±3mm，p=0.004），与 KT-1000 相关（rho 0.316，p=0.008），而 ACLPT 组中第三轴的 ΔAP 倾斜度较小与对照组相比（ΔAP 倾斜度-3 ACLPT-CTRL：-13±5°，p=0.004），在动作期间在 ACL 受伤组中存在显著的侧差异（受伤-未受伤：8±2.7°，p=0.006）。小的 ΔAP 倾斜度-3 与低 Lysholm（rho 0.391，p=0.002）和高 KT-1000（rho-0.450，p=0.001）相关。结论 在着陆过程中，似乎使用了代偿性运动策略来保护受伤的膝关节。受伤膝关节在动作过程中 ΔAP 倾斜度降低表明，即使在受伤后很长时间，动态膝关节控制仍可能受到影响。
