varför är disktrycket större i sittande ställning än vid stående?

[LuThe]

Som titteln löd;

varför är disktrycket större i sittande ställning än vid stående?

[Absinteh]

Vid tex millitärpress eller?

[LuThe]

de e en fråga på idrotten så om nån kunnig tror sig kunna svaret så vore de perfa :D

[Sniggel]

Det har gjorts mätningar av trycket inne på människor (japp med tryckkänsliga nålar rätt in i ryggraden) under olika positioner:
Stående upprätt gav ett mindre utslag på nålarna än sittandes på stol.
Varför det är så vet jag inte.
(detta var med kroppen som enda belastning)

[MasterChief]

Om man har ett högre tryck i sittande än i stående så sitter man nog lite "krummigt" och därmed så blir belastningen förskjuten till ena sidan av disken vilket ökar trycket/areaenhet. Nu har inte jag följt detta så noggrant men det har gjorts nya studier som visar att skillnaden är mindre än man trott och att sittande till och med kan ge lägre tryck om man "sitter rätt".

Hans-Joachim Wilke, PhD,* Peter Neef, MD, Marco Caimi, MD, Thomas Hoogland, MD,§ and Lutz E. Claes, PhD*

Study Design. We conducted intradiscal pressure measurements with one volunteer performing various activities normally found in daily life, sports, and spinal therapy.
Objectives. The goal of this study was to measure intradiscal pressure to complement earlier data from Nachemson with dynamic and longterm measurements over a broad range of activities.
Summary of Background Data. Loading of the spine still is not well understood. The most important in vivo data are from pioneering intra-discal pressure measurements recorded by Nachemson during the 1960s. Since that time, there have been few data to corroborate or dispute those findings.
Methods. Under sterile surgical conditions, a pressure transducer with a diameter of 1.5 mm was implanted in the nucleus pulposus of a nondegenerated L4L5 disc of a male volunteer 45yearsold and weighing 70 kg. Pressure was recorded with a telemetry system during a period of approximately 24 hours for various Iying positions; sitting positions in a chair, in an armchair, and on a pezziball (ergonomic sitting ball); during sneezing, laughing, walking, jogging, stair climbing, load lifting; during hydration over 7 hours of sleeping, and others. Results. The following values and more were measured: Iying prone, 0.1 MPa; Iying laterally, 0.12 MPa; relaxed standing, 0.5 MPa; standing flexed forward, 1.1 MPa; sitting unsupported, 0.46 MPa; sitting with maximum flexion, 0.83 MPa; nonchalant sitting, 0.3 MPa; and lifting a 20kg weight with round flexed back, 2.3 MPa; with fiexed knees, 1.7 MPa; and close to the body, 1.1 MPa. During the night, pressure increased from 0.1 to 0.24 MPa.
Conclusions. Good correlation was found with Nachemson's data during many exercises, with the exception of the comparison of standing and sitting or of the various Iying positions. Notwithstanding the limitations related to the singlesubject design of this study, these differences may be explained by the different transducers used. It can be cautiously concluded that the intradiscal pressure during sitting may in fact be less than that in erect standing, that muscle activity increases pressure, that constantly changing position is important to promote flow of fluid (nutrition) to the disc, and that many of the physiotherapy methods studied are valid, but a number of them should be reevaluated.

[Arne Persson]

Rätt sitter man när man sitter på en hästrygg. :) Dvs håll låren i en liknande position.

[Åse Columbus]

Man ska sitta på sittbenen i bäckenet/rumpan.....du känner de ordentligt om du sätter dig på dina händer....axlarna ska var i linje med dem...du sitter du rätt.

Det finns en anledning till att det heter just sittben. ;)