Centre for Biomechanics Research, AECC University College, UK.
Faculty of Science and Technology, Bournemouth University, UK.
J Biomech. 2020 Mar 26;102:109603. doi: 10.1016/j.jbiomech.2020.109603. Epub 2020 Jan 3.
Continuous dynamic multi-segmental studies of lumbar motion have added depth to our understanding of the biomechanics of back pain, but few have attempted to continuously measure the proportions of motion accepted by individual levels. This study attempted to compare the motion contributions of adjacent lumbar levels during an active weight bearing flexion and return protocol in chronic, non-specific low back pain (CNSLBP) patients and controls using quantitative fluoroscopy (QF). Eight CNSLBP patients received QF during guided standing lumbar flexion. Dynamic motion sharing of segments from L2 to S1 were calculated and analysed for interactions between levels. Eight asymptomatic controls were then matched to the 8 patients for age and sex and their motion sharing patterns compared. Share of intersegmental motion was found to be consistently highest at L2-L3 and L3-L4 and lowest at L5-S1 throughout the motion in both groups, with the exception of maximum flexion where L4-L5 received the greatest share. Change in motion sharing occurred throughout the flexion and return motion paths in both participant groups but tended to vary more at L4-L5 in patients (p < 0.05). In patients, L5-S1 provided less angular range (p < 0.05) and contributed less at maximum bend (p < 0.05), while L3-L4, on average over the bending sequence, provided a greater share of motion (p < 0.05). Intervertebral motion sharing inequality is therefore a normal feature during lumbar flexion. However, in patients, inequality was more pronounced, and variability of motion share at some levels increased. These effects may result from differences in muscular contraction or in the mechanical properties of the disc.
连续的动态多节段腰椎运动研究加深了我们对背痛生物力学的理解，但很少有人试图连续测量各个节段所接受的运动比例。本研究试图使用定量荧光透视术（QF）比较慢性非特异性下腰痛（CNSLBP）患者和对照组在主动负重前屈和返回过程中相邻腰椎节段的运动贡献。8 例 CNSLBP 患者在引导站立腰椎前屈时接受 QF。计算并分析从 L2 到 S1 的节段动态运动共享，并分析各节段之间的相互作用。然后，根据年龄和性别将 8 名无症状对照与 8 名患者相匹配，并比较其运动共享模式。在两组中，除了最大前屈时 L4-L5 获得最大的运动份额外，节段间运动份额在整个运动过程中始终在 L2-L3 和 L3-L4 最高，在 L5-S1 最低。在两组参与者的前屈和返回运动路径中，运动共享的变化贯穿始终，但在患者中变化更多（p<0.05）。在患者中，L5-S1 提供的角度范围较小（p<0.05），在最大弯曲时贡献较小（p<0.05），而 L3-L4 在整个弯曲序列中平均提供更大的运动份额（p<0.05）。因此，腰椎前屈时，椎间盘间运动共享的不平等是正常现象。然而，在患者中，不平等更为明显，一些节段的运动份额的可变性增加。这些影响可能源于肌肉收缩或椎间盘机械特性的差异。
