Laroche Davy, Ornetti Paul, Thomas Elizabeth, Ballay Yves, Maillefert Jean Francis, Pozzo Thierry
INSERM-ERM 207 Motricité & Plasticité, Université de Bourgogne, BP 27877, 21078, Dijon Cedex, France.
Exp Brain Res. 2007 Jan;176(1):85-97. doi: 10.1007/s00221-006-0597-1. Epub 2006 Aug 17.
Rheumatoid arthritis (RA) is a leading cause of disability, which affects primarily the forefoot. Moreover, the forefoot is the final ground body interface for transmitting forces produced by the plantar flexors in order to move the body forward. Therefore, a dysfunction in patients with arthritis might induce important changes in gait, such as modifications in the coordination between legs to correct a reduced range of motion (ROM) and to produce smooth stride motions. First, we wanted to investigate the modifications of gait parameters in order to get a deeper understanding of the locomotor adaptation after a distal joint impairment. Second, we wanted to extract the mechanisms used to compensate for these impairments. In order to carry out this study, RA patients with forefoot impairment and healthy subjects were asked to walk along a straight line at two different velocities and were recorded by a motion analysis system. Patients were able to produce an efficient pattern despite a reduction of the ROM of the forefoot. At normal speed, the substantial modification of the locomotor pattern was linked to the adaptation of the lower-limb segment coordination and to the loss of ROM. Compensative mechanisms are the results of an efficient adaptation that offset the effect of the lesions. In contrast, at high speed, all of the kinematic modifications observed at natural speed vanished. It seems that pain and its associated sensory signals help to update the motor command and compel patients to adjust the descending command to the altered representation of distal mobility. Finally, the mechanical consequences of these changes are of particular interest since different levels of force exerted at the hip, knee and ankle might result in a supplementary structural alteration of these joints.
类风湿性关节炎（RA）是导致残疾的主要原因，主要影响前足。此外，前足是传递跖屈肌产生的力量以使身体向前移动的最终地面与身体的接口。因此，关节炎患者的功能障碍可能会引起步态的重要变化，例如腿部之间协调性的改变，以纠正运动范围（ROM）的减小并产生平稳的跨步动作。首先，我们想研究步态参数的变化，以便更深入地了解远端关节损伤后的运动适应性。其次，我们想找出用于补偿这些损伤的机制。为了进行这项研究，患有前足损伤的类风湿性关节炎患者和健康受试者被要求以两种不同速度沿直线行走，并由运动分析系统进行记录。尽管前足的ROM减小，患者仍能够产生有效的模式。在正常速度下，运动模式的显著改变与下肢节段协调性的适应以及ROM的丧失有关。补偿机制是有效适应的结果，可抵消损伤的影响。相比之下，在高速时，在自然速度下观察到的所有运动学改变都消失了。似乎疼痛及其相关的感觉信号有助于更新运动指令，并迫使患者根据远端活动能力的改变调整下行指令。最后，这些变化的力学后果特别令人关注，因为在髋部、膝盖和脚踝施加的不同水平的力可能会导致这些关节的额外结构改变。
