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Designing for Upper Torso and Arm Anatomy
Published in Karen L. LaBat, Karen S. Ryan, Human Body, 2019
Vertebral shapes affect spinal movement and stability. The cervical, thoracic, and lumbar spine vertebrae are movable and become larger the farther they are from the head. The thoracic vertebrae connect with ribs; first ribs articulate with the first thoracic vertebra (T1), and so on. The bodies of the five lumbar vertebrae in the lower back, L1–L5, are sturdier than the vertebrae above, because they bear the accumulated weight of the head, neck, and torso (White & Folkens, 2005, p. 159).
Trunk motion control during the flight phase while hopping considering angular momentum of a humanoid
Published in Advanced Robotics, 2018
Takuya Otani, Kenji Hashimoto, Takaya Isomichi, Akira Natsuhara, Masanori Sakaguchi, Yasuo Kawakami, Hun-ok Lim, Atsuo Takanishi
Based on motion analyses of the upper body during human running, it is known that the trunk, waist, and pelvis behave differently [26]. Here, the trunk refers to the parts higher than the lumbar vertebrae, and the pelvis refers to parts lower than the lumbar vertebrae (Figure 2). The lumbar vertebrae in the waist consist of five cylindrical bones that form the spine in the lower back. In the flight phase during running, the long axis of waist maintains a posture that is close to vertical, and the trunk and arms are rotated. This posture is adopted because the upper body adjusts the angular momentum of the waist by compensating for the angular momentum generated by the leg motion [8], which contributes to preventing waist rotation. A major feature of the hopping and running motion is that the dynamics of the system are different between the stance and flight phases. In the stance phase, a human or robot can get a reaction force from the ground by touching the ground. On the other hand, as they are not in contact with the ground during the flight phase, the total angular momentum does not change. Thus, the magnitude of the total angular momentum can be controlled only during the stance phase. In the flight phase, the legs, which are far from the waist, perform a motion to generate a large angular momentum by quickly swinging to change the next landing position. Consequently, when the legs generate a large angular momentum during the flight phase, the angular momentum of the whole body remains constant, which causes the body to rotate in the opposite direction, especially at the waist. Therefore, to maintain a vertical waist posture during the flight phase, compensation must be provided for the angular momentum induced by the lower-body motion including legs and pelvis in the upper body including arms and trunk.
Finite element mechanics analysis of lumbar spine with normal and varying degrees of herniated lesions under different working conditions and material properties
Published in Mechanics of Advanced Materials and Structures, 2022
Yu Hui, Ze-xun Zhou, Jing Du, Bo Wu, Wei Huang
Compared with the result of using the traditional ray casting method to draw, the MC algorithm is faster to draw and can meet the performance requirements of real-time observation of the model. The result of using the MC algorithm to draw the surface is shown in Figure 2. The bottom five vertebrae are the human body L1–L5 lumbar vertebrae segments.