Abstract:
This study investigated the effect of anterior cruciate ligament (ACL) injury on relative acceleration of the tibia and femur during a number of tests/activities, in order to assess the feasibility of acceleration-based diagnosis of ACL injury using inertial sensors. First, a detailed finite element model of the knee joint was developed to simulate the target tests/activities, and identify those in which a large difference between the maximum acceleration peaks (MAPs) of the healthy and ACL injured knees is likely to be observed. The promising tests/activities were entered in an experimental study, where the relative accelerations of the tibiae and femurs of 20 individuals with unilateral ACL injury, allocated randomly to two groups of conscious and unconscious test conditions, were recorded. Model predictions indicated MAP ratios>1.5 for the ACL-injured to healthy knees, during the anterior drawer, Lachman, and pivot-shift tests, as well as the lunge activity. The experimental MAP results indicated acceptable test-retest reliabilities for all tests (coefficient of variation<0.25), and significant MAP differences (p < 0.05) in the anterior drawer and pivot-shift tests, in both coconscious and unconscious conditions. The individualized MAP results indicated side-to-side differences>2 m/s2 for all subjects during unconscious pivot shift tests, and >0.5 m/s2 for eight cases out of ten during conscious anterior drawer tests. It was concluded that the pivot shift test had a great repeatability and discriminative ability for acceleration-based diagnosis of ACL injury in unconscious condition. For the conscious condition, however, the anterior drawer test was appeared to be most promising.
摘要:
这项研究调查了在许多测试/活动中,前交叉韧带(ACL)损伤对胫骨和股骨相对加速度的影响。为了评估使用惯性传感器基于加速度诊断ACL损伤的可行性。首先,开发了膝关节的详细有限元模型来模拟目标测试/活动,并确定可能观察到健康膝盖和ACL受伤膝盖的最大加速度峰值(MAP)之间存在较大差异的那些。有希望的测试/活动被输入到一项实验研究中,其中20名单侧ACL损伤患者的胫骨和股骨的相对加速度,随机分配到两组有意识和无意识的测试条件,被记录下来。模型预测表明,ACL损伤至健康膝盖的MAP比率>1.5,在前抽屉里,拉赫曼,和枢轴移位测试,以及弓步活动。实验MAP结果表明,所有测试的测试-重测可靠性均可接受(变异系数<0.25),在前抽屉和枢轴移位试验中,MAP差异显著(p<0.05),在无意识和无意识的条件下。个性化的MAP结果表明,在无意识枢轴移位测试期间,所有受试者的侧向差异>2m/s2。在有意识的前抽屉试验中,十分之八的病例>0.5m/s2。结论是,枢轴移位测试对于无意识状态下基于加速度的ACL损伤诊断具有很大的可重复性和辨别能力。对于有意识的状态,然而,前抽屉试验似乎是最有希望的。