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On the classification of the human spinal column
Last reviewed: 23.04.2024
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The human musculoskeletal system, from the point of view of biomechanics, is a system of biokinematic chains, all of whose biocords are combined into biokinematic pairs and have connections that determine their external freedom of movement.
Laputin (1986) developed the first biomechanical classification of the musculoskeletal system, the principles of biomechanical modeling of its joints and individual links. In it, 246 biokinematic pairs and 8 biokinematic chains were isolated.
The abbreviation for the biokinematic chain is the Latin letters VKS (bios, kinesis, catena - biologically moving chain) and the index consisting of the Latin letter P (pars - part) of the initial letter of the Latin name for the part of the body or skeleton.
In the records of biokinematic pairs in the abbreviation of the VCS, the last letter is replaced by P. To indicate which chain the pair belongs to, the abbreviation preserves the index of the corresponding chain (for example, SRS is the pair of the spinal column). In this case, however, it is impossible to establish which of these is the pair: we should also inform its serial number, starting from the proximal end of the spinal column - SRS. "(Or su-10). For brevity, biokinematic links (BKS) are named after the first letters of Latin anatomical names of bones. If the two links have the same name, for example vertebra in the vertebral column, then they are called from the proximal end of the chain.
The vertebral column is a complex multi-link biokinematic chain (VCS-1), formed by the atlanto-occipital articulation, which unites the skull and first cervical vertebra. Thus, it is possible to define the name of all biokinematic pairs of VCS: C-1 - own pair of skulls; cv-1 - a pair formed by the biopsy of the skull and I vertebra C1; cv-2 - a pair of vertebrae C1 and C2, etc. The last 26th pair (cv-26) includes the biochairs of the sacrum and coccyx.
Since the various movements of the spinal column are autonomous, it is advisable to distinguish three more chains in its general biokinematic chain, determined by the presence of three moving parts - cervical, thoracic and lumbar: cvc - biokinematic chain of the cervical region; cvt - biokinematic chain of the thoracic region; cvl - biokinematic chain of the lumbosacral coccygeal department.
The thoracic cage consists of numerous bone formations of complex shape, possessing different degrees of mobility. Nevertheless, it can be represented as a single biokinematic chain VKST. The thoracic vertebrae refer both to the biokinematic chain of the spinal column and to the biokinematic chain of the thorax. Connections VKSvv and VKShh, carried out in the area of articulations of the ribs and vertebrae. Therefore, according to the present biomechanical nomenclature, these formations are designated as compounds of two relatively mobile chains, and the joints themselves, for the purpose of a more detailed study of movements, are considered separately when observing the movements of the ribs and sternum. In essence, such a division does not represent the dismemberment of an integral region, but only facilitates its study in comparatively simple parts.
The four lower free ribs can practically move independently of other chest bio-units, they are connected together with the vertebrae, which sometimes allows them to be considered as independent bio-links, associated only with the vertebral column.
According to the biomechanical classification, in the biokinematic chain of the chest there are 40 basic biokinematic pairs and 4 additional pairs. Since each rib connects to the breastbone with its thoracic part, and with vertebrae - the vertebral column, it basically forms two pairs (one with the vertebrae, the other with the sternum). In view of this, the indices "a" (anterior - front) and "p" (posterior), "s" (sinister - left), "d" (dexter - right) were added to the names of all pairs instead of ordinal figures.