The Effects Of High Speed Treadmill Walking On Gait Quality Of Incomplete SCI

Objective:Spinal Cord Injury(SCI)is the leading cause of long-term disability.Not surprisingly,the locomotors deficits observed following SCI have a profound impact on functional independence and have been positively correlated with fall risk and energy cost and negatively correlated with participation in the community.Thus,there is a growing body of literature exploring the mechanisms underlying gait abnormalities and possible rehabilitation interventions after SCI.Treadmill training(with or without body-weight support)has emerged as an intervention that improves walking speed in people who have had a SCI and stroke.In addition,one of the proposed benefits of treadmill training is that it facilitates practice of a more normal walking pattern.Another benefit of treadmill training is that it allows massed stepping practice.Thus,treadmill training may result in repetitive,intensive practice of a more normal gait pattern after SCI.But the speed selection is a critical factor for treadmill training,and the effect of high speed treadmill training on gait quality of SCI patients was unclear till now.And it was unclear if there were other parameters to quantify the quality of gait between patients with spinal cord injury and healthy subjects.So,the aim of this research was to compare the difference of the parameters for the quality of gait between patients with spinal cord injury and healthy subjects,and to explore the effect of high speed treadmill walking training on gait quality of incomplete SCI patients.Methods:17 healthy subjects were included in this experiment(Male 13,female 4).Subjects walked comfortably on the treadmill when the treadmill speed was slowly increased.And spontaneously transited from walk to run or from run to walk on a treadmill at a different acceleration(a=0.02m/s~2,0.04 m/s~2,0.06 m/s~2 separately)driven by treadmill surface.The data of demographics of fifty-one participants including 28 healthy subjects and 23 SCI subjects were evaluated.Then the subjects were required to walk on the footscan plantar pressure system at their comfortable speed.The walking speed,spatio-temporal variables and pressure parameters were extracted and computed percentage and Symmetry Index.17 patients with SCI(whose ASIA level were D)were randomly divided into two treadmill training group:high speed treadmill walking group(TWG)and normal speed overground walking group(NWG).Using footscan system,spatiotemporal gait parameters and the parameters of plantar pressure were measured before and after training.Results:The step length was lineally increased following with the increasing speed,the WRT speed in the higher acceleration group(a=0.06 m/s2)was significantly higher than that in the lower one(a=0.02 m/s2).but the RWT speed was lower,and the hysteresis(difference between the WRT speed and the RWT speed)was significantly higher.The step length was lineally increased following with the increasing speed,but was decreased near to the WRT step,and after 3-4 steps decreasing,it was lineally increased again.Comparing with healthy subject,the walking speed in the patients with SCI was significantly lower(P<0.05),the stride time and the stance time was significantly longer and the stance phase percentage was significantly larger(P<0.05),while the stride length was significantly shorter(P<0.05),and the peak pressures under the metatarsal heads and toe were significantly lower in patients with SCI(P<0.05);in the region of heel(Heel Medial and Heel Lateral),regional impulse and the contact area percentage in patients with SCI was significantly higher(P<0.05).In the patients with SCI,the Symmetry Index of stance time and step length were significantly larger than that in healthy group,and for pressure variables,the Symmetry Index of Maximum Force,impulse and contact area were all significantly larger in patients with SCI(P<0.05).After treadmill training,the overground walking speed was higher in the TWG group than that in the NWG group.In the TWG group,the stance time percentage was decreased and the swing time percentage was increased,especially in the weak side.The symmetry index of the stance phase,swing phase,step length was significantly improved in TWG group,and there were significant more improvements in step length symmetry index in TWG group than that in NWG group.The symmetry index of impulse in both group were improved.Conclusion:When a higher treadmill speed was imposed,the increasing step length and cadence was found.When a higher acceleration was imposed,the speed of WRT was significantly higher,while RWT was lower,and the hysteresis was significantly larger.The transition process was observed in all accelerations.There was difference in the spatiotemporal parameters between the patients with SCI and healthy subjects.In the patients with SCI,the walking speed was lower,the stance phase was larger and step length was shorter than that in healthy subjects.The symmetry index was larger in the patients with SCI.For the patients with SCI,the higher treadmill speed can lead to a more symmetrical gait pattern,and after a high speed treadmill training,the overground speed was increased and step length and the symmetry index of step length was significantly improved.