| Object: This research studied the biomechanical characteristics of unilateral transfemoral amputees during walking on level ground and stairs,aiming to analyze the biomechanical characteristics of amputees when using existing prosthetic products to walk,and provide some reference for the optimization of the structure and function of the prosthesis.The program also provides clinical data support for our country’s research on high-performance prostheses of independent brands.Method: In this study,Vicon three-dimensional motion capture system,Pedar-X insole type plantar pressure measurement system and Tele Myo 2400 T DTS Surface Electromyography System were used to collect the kinematics,surface electromyography and plantar pressure parameters of 10 unilateral transfemoral amputees and 10 normal subjects during walking on flat ground and stairs,and analyze the biomechanical characteristics of the lower limbs of unilateral transfemoral amputees and normal people,including: 1.The motion angles of hip,knee and ankle joints in the sagittal,coronal and horizontal planes;2.The integrated electromyogram(i EMG)of erector spinae(ES),gluteus maximus(GMax),gluteus medius(GMed),rectus femoris(RF),biceps femoris long head(BF),tibialis anterior(TA),medial gastrocnemius(MG),lateral gastrocnemius(LG).3.Peak pressure of the medial heel,lateral heel,medial mid-foot,lateral mid-foot,metatarsal 1,metatarsal 2-3,metatarsal 4-5,hallux,and toes 2-5 area.Analyze the biomechanical problems of the prosthesis,and provide data support and reference solutions for the optimization of the structure and function of the prosthesis.Result:1.Kinematics results(1)Ankle joint angleIn the amputation group,during walking on level ground and going up and down stairs,the range of motion(ROM)in the sagittal and coronal planes,dorsiflexion,plantarflexion and inversion angles of the prosthetic side ankle joint were significantly smaller than those of the normal group(P < 0.05);when going up and down the stairs,the plantarflexion movement on the side of the prosthesis disappeared;when walking on level ground and going down stairs,the external rotation angle of the prosthetic side ankle joint was significantly smaller than that of normal group(P<0.05).When going up the stairs,coronal plane ROM and eversion angle of intact side ankle joint were significantly larger than that of the normal group(P<0.05);when going down the stairs,the angle of external rotation was significantly larger than that of normal group(P<0.05).(2)Knee joint angleIn the amputation group,when walking on the ground,the first flexion peak value of the prosthetic knee joint was significantly lower than that of the intact side and the normal group(P<0.05);when going up and down the stairs,the sagittal plane ROM and flexion angle were significantly smaller than those of the normal group and the intact side(P<0.05);when walking on level ground and going up and down stairs,the coronal plane ROM,horizontal plane ROM and valgus angle were significantly smaller than those in the normal group(P<0.05).When going up the stairs,the coronal and horizontal plane ROM of the intact side knee joint were significantly larger than those in the normal group(P<0.05).(3)Hip joint angleWhen going up and down stairs,the sagittal plane ROM and maximum flexion angle of the hip joint on the prosthetic side were smaller than those of the intact side and the normal group(P<0.05);when walking on the ground,the coronal plane ROM and the angle of external rotation were significantly smaller than those of the normal group(P<0.05).When going up the stairs,the horizontal plane ROM and minimum flexion angle of the intact hip were significantly larger than the normal group(P<0.05);when going down the stairs,the abduction angle was significantly larger than the normal group(P<0.05).2.Surface electromyography parameter resultsWhen walking on level ground,the i EMG of GMax,GMed and ES of the prosthetic side was significantly greater than that of the normal group(P<0.05);when going up the stairs,the i EMG of GMed was significantly greater than that of the normal group(P<0.05);when going down the stairs,the i EMG of GMax and ES was significantly greater than that of the normal group(P<0.05).When walking on level ground,the i EMG of the GMax,ES,BF,MG,and LG of the intact side was significantly greater than that of the normal group(P<0.05);when going up the stairs,the i EMG of BF and TA was significantly greater than that of the normal group(P<0.05);when going down the stairs,the i EMGs of GMax,ES,BF and LG were significantly greater than those of the normal group(P<0.05).3.Plantar pressure parameter resultsWhen walking on level ground,the peak pressure of the medial heel and lateral heel of the prosthetic side was significantly higher than that of the intact side(P<0.05);when going up the stairs,the peak pressure of the hallux was significantly lower than that of the normal group and the intact side(P < 0.05);when going down the stairs,the peak pressures of medial mid-foot,medial heel and lateral heel were significantly higher than those of the intact side;while the peak pressures of the metatarsal 1-5 and the toe 1-5 were significantly lower than those of the intact side(P<0.05).Conclusion:1.The prosthetic side ankle joint dorsiflexion and plantarflexion angles of amputees are insufficient.When going up and down the stairs,the plantarflexion movement disappears,and the foot kicking ability and foot clearance ability decrease.In addition,the motion angle of the prosthetic ankle joint in the coronal and horizontal planes is insufficient,which makes it difficult for amputees to adapt to the complex terrain environment and increase the difficulty of walking,while the intact ankle joint has corresponding compensatory movements.2.The flexion angle of the prosthetic knee joint in the support phase is obviously insufficient.When the amputees walk on the ground,the first flexion peak of the prosthetic knee joint disappears,and the walking style changes when going up and down the stairs,relying on the intact side to provide power,which increases the burden on the intact limb.At the same time,the prosthetic knee joint lacks coronal and horizontal plane motion,which causes the compensatory increase of the motion range of the intact knee joint on the coronal and horizontal plane when the amputee goes up the stairs.3.The hip joint on the prosthesis side is affected by the angle of motion of the knee and ankle joints,and there is also a phenomenon that the angle of motion decreases.The coronal ROM and the angle of external rotation decrease when walking on the ground,and the sagittal ROM decreases when going up and down the stairs.The compensation of horizontal ROM increased when the intact hip went upstairs,and the compensation of abduction angle increased when downstairs.4.In the process of walking on level ground and going up and down the stairs,the mobilization and recruitment of motor units of the main muscles of both limbs of amputees increased significantly,showing compensatory activities of the intact limbs.5.In the process of walking on level ground and going up and down stairs,the pressure distribution on the soles of the amputees changes on both sides,showing obvious asymmetry.Based on the results of this study,the following optimization suggestions are proposed for the prosthesis: in the subsequent research and development of the prosthesis,it is necessary to optimize the flexion and extension function of the knee joint,provide appropriate power or joint damping in the support phase,and also optimize its movement on the coronal and horizontal planes;when optimizing the prosthetic ankle-foot,it is necessary to optimize the ability to kick off the ground and flexibility of the foot,and increase the angle of movement of the ankle joint in the sagittal,coronal,and horizontal planes. |
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