Web research.

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Note added at 12 hrs (2014-05-15 22:19:08 GMT)
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1) Segment ruchowy kręgosłupa jest to najmniejsza jednostka funkcjonalna w jego obrębie. Pojęcie segmentu ruchowego wprowadzili Christian Georg Schmorl i Junghanns. Składa się on z dwóch sąsiadujących kręgów, dwóch stawów międzykręgowych, krążka międzykręgowego oraz pozostałych struktur łączących powyżej wymienione elementy

2) A functional spinal unit (FSU) is the smallest physiological motion unit of the spine to exhibit biomechanical characteristics similar to those of the entire spine.[1]
A FSU consists of two adjacent vertebrae, the intervertebral disc and all adjoining ligaments between them and excludes other connecting tissues such as muscles. The three-joint complex that results is sometimes referred to as the "articular triad." Another term for the FSU is spinal motion segment.

3) spinal motion segment -two adjacent vertebrae and the connecting tissues that bind them together.
http://medical-dictionary.thefreedictionary.com/spinal motio...

4) Although the spinal motion segment has received considerable attention, the ... following the inference made by Schmorl and Junghanns (1932), who called the
http://www.tau.ac.il/~anatom2/clin_anat_past.html