1994, 9(1):1-15. DOI: 10.3871/j.1004-7220.1994.01.15.
Abstract:The objective of this study is to evaluate the surgical outcome of anterior displacement of the tibial tuberosity,(Maquet procedure)for reducing Patellofemoral joint contact force The in vivo experimental knee joint geometric data with a biomechanical model were used to simulate the Maquet procedure.Six healthy young adults performed weight-bearing knee flexion-extension by ascending a one-step stair.Dynamic X-ray images of the knee were continuously recorded by a video-fluoroscopic system.These X-ray images were analyzed on a computerized digitizing system to get the knee joint geometric data.Based on the continuous in vivo geometric data,computer surgery simulation was studied on 6 right knees with advancement of 3,5,10,15,and 20 degrees of tlie patellar tendon insertion.Evaluation of the simulation consequences from a biomechanical view point showed that the Maquet procedure reduced the patellofemoral joint reaction force only up to 207% at 90 degrees of knee flexion angle.The patel lofemoral joint reaction force had 50% reduction only when the knee flexion angle was less than 20degrees, and only when patellar tendon was moved outwards by 15 or 20 degrees.This represented nearly one inch of the anterior displacement of the tibial tuberosity.The results also showed that the Maquet procedure would decrease up to 20% of the force transmission effciency of the patellofemoral mechanism,which would cause the mechanical consequences of the operation to be only minor at knee flexion angles greater than 20 degrees.These findings suggest that the Maquet procedure is only favorable to elderly or less active patients assuming small knee flexion angle activities.
1994, 9(1):16-20. DOI: 10.3871/j.1004-7220.1994.1.20.
Abstract:By way of three-dimensional measuremont,the kinematics of the cervical spine after partial discoidectomy was studied on 8 specimens of functional spinal units from dogs.Each specimen was subjected to partial discoidectomy,fixed on a frame and given proper load.Records of the 3-dimensional motions,before and after partial discoidectomy were compared carefully.The data demonstrated that the partial discectomy did bring about definite ill-effect on kinematics of the cervical spine.
1994, 9(1):21-25. DOI: 10.3871/j.1004-7220.1994.01.25.
Abstract:This paper report a study of three-dimensional(3D)reconstruction and dynamic display for a series of CT images of lumbar vertebral canal.It provides a newresearch method for the spinal column biomechanics.By means of the contour reconstruction we made 3D reconstruction for complete human lumbar vertebra.The reconstructive graphic could be rotated cut and transformed in any orientation.It could realize dynamic display and accurately show the structure and form of lumbar vertebral canal.Based on the 3D image reconstruction,image processing.technique was used to measure the spinal canal effective area(SCEA)after dynamic exchange and get the result of the percentage of effective area.The result showed the dynamic exchange of SCEA was related to the clinical symptom and the therapeutic effect of the lumbar vertebra disease.This method of spinal Canal CT image 3D reconstruction could extend its use into other fields.
1994, 9(1):26-33. DOI: 10.3871/j.1004-7220.1994.01.33.
Abstract:An analysis of mechanical characteristics of the anatomical,overlap,angle or rotation reductions of clavicle fracture is performed by the finite element method.The calculated joint forces,the stress or displacement patterns indicate that correct reduction is very important.Improper reduc tion techniques will not only result in cosmetic change,but also induce,in some serious cases,great lccal stresses,which give rise to traumatic arthritis.
1994, 9(1):34-40. DOI: 10.3871/j.1004-7220.1994.01.40.
Abstract:A nonlinear unrestrained seating human dynamic model is given to simulate seating shipboard personnel.The calculating results of nonlinear model are in good accordance with the human shock experimental results in David Taylor Model Basin(NSRDC).It's shown that the nonlinear model is more advantageous than Payne's linear model.The modified nonlinear seating human model may be used to predict injury probability of seating shipboard personnel to real ship underwater explosion shock.With this model,we can draw up the seating shipboard personnels'tolerance curves to ship shock induced by underwater explosion.
1994, 9(1):41-44. DOI: 10.3871/j.1004-7220.1994.1.44.
Abstract:Taking advantage of the technique of Computerized Tomography(CT)and the functions of the Digital Image Processing System(DIP)in this paper,50 young female medical students were scanned by CT from head to foot.The achieving images were imported into DIP and were processed by it.According to the dark degree of the tissues in the image and the determined density of the various tissues, the weight and mass center of the segments and the total body of every individual was counted with the DIP.Going through the analysis,examination,and statistics,the accuracy and reliability of the data was defined.Thus,a dependable data was provided for building up the model of the inertialparameters of the Chinese human body and for Sporting movement.
1994, 9(1):45-51. DOI: 10.3871/j.1004-7220.1994.01.51.
Abstract:This paper gives a method to measure in-plane strain of skew ruled surface shell by using Moire interferometry of sticking film method.The varied pitch gratings are made,principle of measurement,explanation of the Moire fringes of varied pitch gratings,establishment of formulas,analysis of precision,experimental technique, as well as the application to human maxillary complete denture base are discussed in this study.The good results verify that it is an applicable method.