Analysis of Plantar Pressure before and after Occurrence of Neurogenic Intermittent Claudication in Patients with Central Lumbar Spinal Stenosis / 医用生物力学

Objective To investigate the changes of plantar pressure distributions and risk of falling before and after the occurrence of neurogenic intermittent claudication (NIC) in patients with central lumbar spinal stenosis (LSS), so as to provide theoretical and data references for the application of plantar pressure analysis in judgment of walking abilities for LSS patients. Methods Twelve patients with LSS at the L4-5 segment were selected as the LSS group, while twelve healthy adults at the same age were selected as the control group. Footscansystem was used to measure plantar pressure of these subjects during walking. Contact area percentage of the total foot contact area (CA%), pressure-time integral (PTI), foot progression angle (FPA), contact time percentage of the stance time (CT%) and total stance time (CT) in both LSS group and control group were compared to evaluate changes of plantar pressures during walking．Results Before the occurrence of NIC, compared with the control group, the LSS group had lower CT% during the forefoot push-off phase (FFPOP) and higher CT% during the initial contact phase (ICP), the total CT and FPA also increased, and the PTI of the 1st-3rd metatarsals and the CA% of the 2nd and 3rd metatarsals were higher. After the NIC occurred, for LSS group, CT% during ICP and forefoot contact phase (FFCP) decreased, CT% during the foot flat phase (FFP) and FFPOP as well as total CT and FPA increased, the PTI and CA% increased in 1st-4th metatarsals. Moreover, the CA% also increased in toe zone, both the PTI and CA% decreased in heel zone. Conclusions In patients with central LSS during walking, the distribution of plantar pressure shifts forward, with abnormal phase of the stance time occurring. Such abnormality will be further aggravated by NIC, indicating a higher risk of falling.