高低节段脊髓损伤截瘫患者轮椅推进的生物力学特征

Biomechanical characteristics of paraplegia individuals with high or low level spinal cord injury on during manual wheelchair propulsion

本研究探究损伤节段在轮椅推进过程中对肩关节负荷的影响,为揭示脊髓损伤患者慢性肩痛的生物力学机制提供理论依据。招募16名截瘫受试者(高节段截瘫组8名,低节段截瘫组8名)和8名健康人模拟轮椅推进活动,同步采集关节运动学、手推圈反作用力和上肢肌电数据,定量评价高、低损伤节段患者手推轮椅时上肢肌肉活动与手推圈反作用力差别,分析诱发慢性肩痛主要的生物力学因素。研究结果表明:各组受试者的推进相占比约为完整周期的前60%;各组间的肩、肘关节运动角度无显著差异;高节段截瘫组手推圈反作用力峰值显著低于低节段截瘫组(P<0.05);高节段截瘫组上肢肌肉表面肌电的平均幅值与积分值显著高于低节段截瘫组(P<0.05)。在轮椅推进过程中,两组患者的上肢运动习惯没有区别,高节段截瘫组的手推圈反作用力仅为低节段截瘫组的70%左右,但高节段截瘫组的肌肉激活程度约为低节段截瘫组的1.4~1.7倍,高节段截瘫组的肌肉做功效率更低。因此,手推圈反作用力的大小或许并非脊髓损伤患者肩痛的主要诱因,肌肉疲劳导致的慢性损伤可能才是高节段脊髓损伤患者肩痛高发的主要原因,也造成了发病率的差异。

To determine the effects of injury level on shoulder joint weight bearing during wheelchair propulsion biomechanical characteristics so as to provide theoretical basis for explaining the biomechanical mechanism behind chronic shoulder pain in individuals with spinal cord injury.Sixteen subjects with paraplegia(high level group with eight subjects and low level group with eight subjects)and eight able-bodied adults were recruited to simulate wheelchair propulsion activities.The pushrim forces,joint kinematics and surface EMG data were collected synchronously during the test for biomechanical analysis of the main factors inducing the chronic shoulder pain.The results showed that the push phase was about the first 60%of the complete cycle.There was no significant difference in upper limb kinematics between the groups.The pushrim forces showed significantly lower peak values in high level paraplegia group than in low level paraplegia group(P<0.05),while the average surface electromyography(sEMG)amplitudes of all four muscles were found significantly the highest in high level paraplegia group(P<0.05).The results also showed that there was no difference in propulsion habits between individuals with high or low injury level paraplegia.The pushrim forces in high level paraplegia group was only about 70%of that in low level paraplegia group,while the muscle activation in high level paraplegia group was 1.4-1.7 times that in low level paraplegia group,suggesting that the efficiency of muscle work in high level group was lower than that in low level group.The prevalence of shoulder pain was higher in individuals with high level paraplegia than that in individuals with low level paraplegia.Since the pushrim forces was lower in high level group,the muscle fatigue may be the main factor leading to chronic shoulder pain and causing the difference in the incidence.