Nessler Jeff A, De Leon Ray D, Sharp Kelli, Kwak Eugene, Minakata Koyiro, Reinkensmeyer David J
Department of Mechanical & Aerospace Engineering, University of California, Irvine, California 92697-3975, USA.
J Neurotrauma. 2006 Jun;23(6):882-96. doi: 10.1089/neu.2006.23.882.
There is a critical need to develop objective, quantitative techniques to assess motor function after spinal cord injury. Here, we assess the ability of a recently developed robotic device (the "rat stepper") to characterize locomotor impairment following contusion injury in rats. In particular, we analyzed how the kinematic features of hindlimb movement during bipedal, weight-supported treadmill stepping change following contusion, and whether these changes correlate with the recovery of open field locomotion. Female, Sprague-Dawley rats (n=29, 8 weeks of age) received mid thoracic contusion injuries of differing severities (11 mild, nine moderate, nine severe, and four sham). In a first experiment, 16 of the animals were evaluated weekly for 12 weeks using the robotic stepping device. In a second experiment, 17 of the animals were evaluated every other day for 4 weeks. The contused animals recovered open field locomotion based on the Basso, Beattie, and Bresnahan Scale (BBB) analysis, with most of the recovery occurring by 4 weeks post-injury. Analysis of 14 robotic measures of stepping revealed that several measures improved significantly during the same 4 weeks: swing velocity, step height, step length, hindlimb coordination, and the ability to support body weight. These measures were also significantly correlated with the BBB score. The number of steps taken during testing was not directly related to intrinsic recovery or correlated to the BBB score. These results suggest that it is the quality of weight-supported steps, rather than the quantity, that best reflects locomotor recovery after contusion injury, and that the quality of these steps is determined by the integrity of extensor, flexor, and bilateral coordination pathways. Thus, by measuring only a few weight-supported steps with motion capture, a sensitive, valid measure of locomotor recovery following contusion injury can be obtained across a broad range of impairment levels.
迫切需要开发客观、定量的技术来评估脊髓损伤后的运动功能。在此，我们评估一种最近开发的机器人设备（“大鼠步进器”）对大鼠挫伤性损伤后运动障碍进行特征描述的能力。具体而言，我们分析了双足、体重支撑的跑步机行走过程中后肢运动的运动学特征在挫伤后如何变化，以及这些变化是否与旷场运动的恢复相关。雌性Sprague-Dawley大鼠（n = 29，8周龄）接受了不同严重程度的胸中段挫伤性损伤（11例轻度、9例中度、9例重度和4例假手术）。在第一个实验中，16只动物使用机器人步进设备每周评估一次，共评估12周。在第二个实验中，17只动物每隔一天评估一次，共评估4周。根据Basso、Beattie和Bresnahan量表（BBB）分析，挫伤动物恢复了旷场运动，大部分恢复在损伤后4周内发生。对14项步进机器人测量指标的分析表明，在相同的4周内，有几项指标有显著改善：摆动速度、步高、步长、后肢协调性以及支撑体重的能力。这些指标也与BBB评分显著相关。测试期间的步数与内在恢复没有直接关系，也与BBB评分无关。这些结果表明，最能反映挫伤性损伤后运动恢复的是体重支撑步的质量而非数量，并且这些步的质量由伸肌、屈肌和双侧协调通路的完整性决定。因此，通过使用运动捕捉仅测量少数几个体重支撑步，可以在广泛的损伤水平范围内获得对挫伤性损伤后运动恢复的敏感、有效的测量。
