ABSTRACT
Objective: To clarify the structure and biomechanical characteristics of the dura mater of the cervical, thoracic, and lumbar segments of sheep, in order to provide a theoretical reference for the study of artificial dura mater. Methods: Five adult male white sheep were sacrificed. The dura mater of C 5, T 10, and L 3 planes were obtained. The histological HE staining was used to observe the internal structure and the thickness of dura mater; the inner and outer surfaces morphology of the dura was observed by scanning electron microscopy (SEM); transmission electron microscopy (TEM) was used to observe the internal structure of dura mater and to measure the diameter of collagen fibers in each part of dura mater. The dura mater of C 6, C 7, T 11, T 12, L 4, and L 5 planes were taken for uniaxial biomechanical test, and modulus of elasticity, tensile strength, and elongation at break were measured. Results: HE staining showed that the thickness of the cervical, thoracic, and lumbar dura mater gradually decreased, and the thickness of the dura mater was (268.19±15.91), (198.16±27.25), (103.74±21.54) μm, respectively, and the differences were significant ( P0.05). Uniaxial biomechanical tests results showed that there was no significant difference in modulus of elasticity, tensile strength, and elongation at break between the axial and transverse dura mater of the cervical dura mater ( P>0.05); the axial data of thoracic and lumbar segments were significantly larger than the transverse data ( P0.05). Conclusion: The thickness of dura mater in sheep decreased gradually from head to tail. There are more collagen fibers and fewer cells on the inner surface of dura mater, while the outer surface of dura mater is covered by cells. The collagen fiberboard layers in the dura mater are arranged alternately, and have obvious anisotropic biomechanical characteristics, and the anisotropic biomechanical characteristics get more significant from the head to the tail.
ABSTRACT
Objective To study the mechanical characteristics of lumbar vertebral manipulation by lifting-rotating and oblique-pulling using multi-film pressure measurement system. Methods Twenty-one male operators were divided into groups of experts, skilled operators and beginners. Everyone completed 7 actions of Lin’s lumbar manipulation continuously, and repeated 3 times. The graphs and data were collected and processed. Results The time-force curve by the experts had regularity. The average pre-load force was (147.25±26.04) N, duration was (0.98±0.20) s, the average minimum force was (79.22±9.50) N, the maximum impact force was (706.26±56.21) N, the flip time was (0.44±0.09) s, and flip speed was (1 666.33±411.91) N/s, the impulse was (310.95±56.67) N·s. The curve graphs and the index by the skilled operators were similar to those by the experts, but the average maximum impact force was (464.51±53.49) N, which was relatively smaller. The curve graphs by the beginners could be broadly divided into three categories. Class Ⅰ was chaotic and unregulated; Class Ⅱ only had impact force and did not have pre-load force, and the maximum impact force varied in size; Class Ⅲ had both impact force and pre-load force, but the forces were relatively small and stable. Conclusions The multi-film pressure measurement system can preferably display the mechanical characteristics of manipulation by lifting-rotating and oblique-pulling, which is an ideal testing tool for quantitative research on mechanical parameters of Lin’s lumbar vertebral manipulation. The experimental results provide a scientific basis for visualization, quantification and standardization of the manipulation.
ABSTRACT
Objective To investigate the effects of tuina manipulation on creep rate and maximal breaking stress of contractural Achilles tendons of rabbits. Methods Twenty-four rabbits were randomly divided into contrac-tural Achilles tendon model group, free activities group and tuina manipulation group. The opposite legs of model group were used as normal controls. Creep rate and maximal breaking stress of Achilles tendons were compared among the 4 groups. Results The average creep rate in tuina manipulation group approximated to that in normal group and was lower than that in model and free activities groups. The average maximal breaking stress in tuina manipulation group approximated to that in normal group and was higher than that in model and free activities groups. Conclusion Tuina manipulation can promote the creep rate and maximal breaking stress of contractura Achilles tendon approximately to normal level. Tuina manipulation may be useful in rehabilitation.