不同类型女性髌股关节疼痛综合征患者的下肢生物力学特征

Biomechanical characteristics of lower limbs in female patients with different types of patellofemoral pain syndrome

背景:目前国内外关于髌股关节疼痛综合征的运动学和动力学研究已经涉及到上下楼梯、行走等日常生活活动。但是不同距下关节状态的髌股关节疼痛综合征年轻女性患者的下肢生物力学特征尚未见报道。目的:探究不同距下关节功能状态的髌股关节疼痛综合征年轻女性患者的下肢生物力学特征,为临床治疗不同类型的髌股关节疼痛综合征提供理论支撑。方法:共纳入受试者33例,其中健康对照组(C组)10例,其余27例髌股关节疼痛综合征受试者根据足姿指数分组,距下关节正常组(A组,足姿指数0-6分)14例,距下关节异常组(B组,足姿指数7-12分)13例。采集各组受试者在正常速度下阶梯时的生物力学指标并进行对比,运动学指标选取初始触地时刻与支撑期屈膝角度最大时刻的髋膝三维关节角度与踝矢状面关节角度;动力学指标选取支撑期屈膝角度最大时刻的髋膝三维关节力矩与踝矢状面关节力矩;表面肌电指标选取股内侧肌、股外侧肌、股直肌、半腱半膜肌、股二头肌和臀中肌在预激活阶段和缓冲阶段的均方根振幅。结果与结论:(1)在初始触地时刻,A组相较于B组有更大的屈膝角度(P <0.05)、髋外旋角度(P <0.01)和更小的膝外旋角度(P <0.01);A组与C组相比有更大的屈膝角度和更小的屈髋角度(均为P<0.01);B组和C组相比有更大的膝外旋角度和更小的髋外旋角度、屈髋角度(均为P<0.01);(2)在屈膝角度最大时刻,A组相较于B组有更小的膝外翻角度(P<0.05)、膝外旋角度(P<0.05)和更大的屈膝角度(P<0.01);A组相较于C组有更小的膝外翻角度(P <0.05)、屈髋角度(P <0.01)和髋外旋角度(P <0.05);B组相较于C组有更小的屈膝角度、屈髋角度、髋外旋角度和更大的膝外旋角度(均为P <0.01);且A组相较于C组有更大的髋内旋力矩(P <0.05)和跖屈力矩(P <0.01);(3)在正常速度下阶梯缓冲阶段时,C组相较于A组有更大的股外侧肌(P <0.05)、股内侧肌(P <0.01)、臀中肌(P <0.01)和股二头肌(P <0.05)激活程度;C组相较于B组有更大的股内侧肌(P <0.01)、臀中肌(P <0.01)和股二头肌(P <0.05)激活程度;A组相较于B组(P <0.05)有更大的半腱半膜肌激活程度;(4)结果表明,髌股关节疼痛综合征年轻女性患者在下阶梯时,髋、膝关节缓冲机制更加僵硬,不足之处可能由踝关节缓冲来代偿;下肢肌肉激活程度低是导致年轻女性罹患髌股关节疼痛的因素;距下关节正常组的下肢生物力学特征异常可能是髋膝关节屈曲不足导致的;距下关节异常组的下肢生物力学特征异常可能是距下关节过度旋前造成的。

BACKGROUND:Currently,research both domestically and internationally on patellofemoral pain syndrome has explored the kinematics and dynamics during daily activities such as stair ascent and descent,and walking.However,there is a lack of studies examining the lower limb biomechanical characteristics of young female patients with patellofemoral pain syndrome in different squatting conditions.OBJECTIVE:To investigate the lower limb biomechanical characteristics among young female patients with patellofemoral pain syndrome in different functional states of the subtalar joint,providing theoretical support for the clinical treatment of various types of patellofemoral pain syndrome.METHODS:A total of 33 participants were included in this study.There were 10 subjects in the healthy control group(group C).The other 27 subjects with patellofemoral pain syndrome were divided into two groups according to the foot posture index:14 subjects in the normal subtalar joint group(group A,foot posture index 0-6 points)and 13 subjects in the abnormal subtalar joint group(group B,foot posture index 7-12 points).The biomechanical indices of the subjects in each group were collected and compared when they walked on stairs at normal speed.The kinematic indices included the three-dimensional joint angles of the hip and knee and the sagittal plane joint angles of the ankle at the initial contact moment and the moment of maximum knee flexion angle during the stance period.The dynamic indices included the three-dimensional joint torques of the hip and knee and the sagittal plane joint torques of the ankle at the moment of maximum knee flexion angle during the stance period.The surface electromyography indices included the root mean square amplitudes of the vastus medialis,vastus lateralis,rectus femoris,semitendinosus and semimembranosus,biceps femoris,and gluteus medius in the pre-activation stage and the buffering stage.RESULTS AND CONCLUSION:(1)At the initial ground contact moment,group A exhibited a greater knee flexion angle(P<0.05),greater hip external rotation angle(P<0.01),and smaller knee external rotation angle(P<0.01)compared to group B.Compared to group C,group A showed a greater knee flexion angle and smaller hip flexion angle(both P<0.01).Group B demonstrated a greater knee external rotation angle and smaller hip external rotation angle and hip flexion angle(all P<0.01)compared to group C.(2)At the moment of maximum knee flexion,group A had a smaller knee valgus angle(P<0.05),smaller knee external rotation angle(P<0.05),and greater knee flexion angle(P<0.01)compared to group B.Compared to group C,group A showed a smaller knee valgus angle(P<0.05),smaller hip flexion angle(P<0.01),and smaller hip external rotation angle(P<0.05).Group B had a smaller knee flexion angle,hip flexion angle,hip external rotation angle,and greater knee external rotation angle(all P<0.01)compared to group C.Additionally,group A exhibited a greater hip internal rotation moment(P<0.05)and plantarflexion moment(P<0.01)compared to group C.(3)At normal speed during the staircase buffering phase,group C showed higher activation levels than group A in the vastus lateralis(P<0.05),vastus medialis(P<0.01),gluteus medius(P<0.01),and biceps femoris(P<0.05).Group C also had higher activation levels than group B in the vastus medialis(P<0.01),gluteus medius(P<0.01),and biceps femoris(P<0.05).Additionally,group A showed higher activation in the semitendinosus and semimembranosus muscles compared to group B(P<0.05).(4)These findings indicate that young female patients with patellofemoral pain syndrome have stiffer hip and knee joint buffering while descending stairs,potentially compensated by the ankle joint.Low muscle activation levels contribute to patellofemoral pain,with those having normal subtalar joints but experiencing pain showing the lowest and most abnormal activation.③Abnormal biomechanics in the normal subtalar joint group are mainly due to insufficient hip and knee flexion.Abnormal biomechanics in the abnormal subtalar joint group are mainly due to excessive subtalar joint pronation.