Ischial Tuberosity Off – Loading When sitting for pain relief

Seat adjustments that take the pressure off the ischial tuberosities help relieve back pain sitting

Biomechanical effects of sitting with adjustable ischial and lumbar support on
occupational low back pain: evaluation of sitting load and back muscle activity
BMC Musculoskeletal Disorders 2009, 10:17 doi:10.1186/1471-2474-10-17 Mohsen Makhsous et al

Full article free here


Spine. 2003 Jun 1;28(11):1113-21; discussion 1121-2. Sitting with adjustable ischial and back supports: biomechanical changes. Makhsous M, Lin F, Hendrix RW, Hepler M, Zhang LQ. abstract here

Having pressure relieved off ischial tuberosities (buttock seat bumps) sets spin in more comfortable position and disc are off-loaded more.

A more full description of that was written up here.

Comment – ergometric seating is fine as long as one realizes that no one can maintain one static position for more than 15 minutes. The only way around that is the rocking chair…

What are some comfortable chairs others have found?

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3 Responses to Ischial Tuberosity Off – Loading When sitting for pain relief

  1. Dr Breck McKay says:

    Sorry.. this is absolute rubbish!
    Look at the evolution of the human posture from four legged animals. Two sets of muscles are critical Psoas and Scalenes… Psoas (eye fillet steaks) have all the ventral rami supplying the legs passing through the muscle body, The scalenes have all the ventral rami of the arm nerves also passing through the muscle body!
    The normal for the PSoas is spine to back leg 110 degrees in 4 legged.. but is now 190 degrees in the upright human. So tight muscles/strained Psoas cause back pain!
    We inject the back/parasacrococcygeal ligs and dorsal rami (as per our modification of S Blomberg Spine 1994) and all the ‘bent oldies’ stand up straight again with massive reduction in their CLBP!

    The correct sitting position is with the seat down and forwards, forming a 110 degree angle again of spine to thigh…

    Check out the Knee chairs for real anatomical comfort
    or even SIMPLER.. Itlaian FitBall makers, produce a “Fit Sit Seat” wedge that does that.. VERY comfortable to sit on..I use them all the time and encourage all my back patients to do so!

    See IASP Discussion Web site for more details.

  2. Ergositter works says:

    Dr Breck McKay,

    Do Ergonomic it is Intellectual

    A pain relieving chair that takes away the contentiously load from the back while seating is invented in Sweden.

    Erik Wallinus who was suffering from low back pain, found a way to ease and finely cure his back pain by seating different than traditional seating. He carried up his body load in seating by taking the load under his thighs instead of his pelvis (ischial, Buttock) and with a proper back support he relived his spine from pressure.

    Now his sons “Tommi” and “Karri” have modified and designed a chair after there fathers way of sitting and filled in the patent formula to protect the idea.

    The future of the new pain reliving chair is the new chair “seat design”, of which the back part of seat (WO-BPS) can be tilted downward (and upward if needed) with respect to the front part of the seat and together with a adjustable back support they have introduced a new and pain free concept and by that also a better ergonomic sitting.

    The inventors introduced the idea to leading science experts in Northern Western University in Chicago USA and to Chalmers Technical University in Sweden. Both University’s have compeered a normal seating posture with the new Ergositter (WO-BPS) posture and have come to the same conclusions and understanding of why Erik could cure his back pain in his new posture.

    The result shoved that the new seat design did not compress the lover spine and realised the spin from the contentiously load from the back while seating.

    Now it looks like that there invention and science co work between USA and Sweden, will changes the ergonomic standards and the inventors hope to get some credit for there findings and can now offer more ergonomic and back pain reliving chairs to back pain suffers in Holland and rest of the world.

    The science has been supported by the US government (NIOSH/CDC) who was funding the project together with Falk Medical Research Trust who was provided the project with generous financial support.

    Here is some comment that the inventor have got on there discovery from leading science expert:

    “I assumed that something like this would show up sometime in the future, but not this soon!”
    Gunnar Andersson, MD, Professsor of Orthopedics, RUSH, Chicago, USA. One of the world’s foremost
    back specialists and an expert on sitting physiology.

    “This is the way all people will be sitting in the future.”
    Christian Höfors Ziebell, PhD, ASSCO prof. Chalmers Technical University in Sweden.. Biomechanic, back specialist.

    “Wouldn’t it be boring if all we talked about was chairs? But wouldn’t it be great if we could see a reduction in the number of people who suffer back pain? Taking the continuous load off your back by using better seating would be a start.”
    Nigel Corlett, Professor in ergonomic comments from Ergonomist, May 2006 UK.

    “Sitting upright with backrest and without ischial support created a desirable condition to reduce the loads on the lower spine and muscle activities”.
    Noshir A. Langrana, PhD, Department of Mechanical and Aerospace Engineering, Rutgers State University of New Jersey, comment from SPINE Volume 28, Number 11, pp 1113–1122 USA

  3. radha sharma says:

    I am a journalist working with a leading newspaper in India. I am 37 years old and was diagnosed with avascular necrosis of the hip joint. I got core decompression done two years ago after which my AVN is static on MRI since two years. I however have been suffering from ischial tuberosity and bursitis due to excessive loading due to sitting for most part of the day. My doctors here advise me to off load by sitting on soft pillows but it does not help and does not lead to real off-loading. Since I am in my prime years, I have to work and support my family. Will you be able to suggest me changes I should make in sitting posture to off load and hence manage pain better. The chair design seems it will be able to help me but is there any way I can buy it?? Is any other aid available that can come to my rescue. I know this is a platform for doctors but I would be indebted if I can be helped.

    Cortisone injection is supposed to be helpful though I suspect it is not as easy an injection as one would think. Imaging shows the bursa is constructed with multiple small cysts:
    Diagnosis Value of Spiral CT in Ischial Tuberosity Bursitis
    YI Wen-zhong,LI Wei-jin
    Journal of Practical Medical Techniques 2008-12

    or septal divisions:
    Non-Infectious Ischiogluteal Bursitis: MRI Findings
    Kil-Ho Cho, MD,1 Sung Moon Lee, MD,2 Young Hwan Lee, MD,3 Kyung Jin Suh, MD,4 Sung Moon Kim, MD,5 Myung Jin Shin, MD,5 and Han Won Jang, MD1
    Korean J Radiol. 2004 Oct-Dec;5(4):280-286.

    This means injecting one spot might not spread all over. I map out the area of tenderness and inject each area. I suspect 40 mg triamcinolone might not be enough and also suspect repeat injection would be necessary to get it all.

    I suspect they is more to it then just ischial bursitis. The inability to sit is seen in tethered hamstrings (scarred down on sciatic nerve) and hamstring upper triggers:

    Ann Chir Gynaecol. 1991;80(2):212-4.
    The hamstring syndrome–a new gluteal sciatica.
    Puranen J, Orava S.
    “The pain is typically incurred by assuming a sitting position”

    A Standing Complaint: Inability to Sit: An Unusual Presentation of Medial Hamstring Myofascial Pain Syndrome
    Robert D. Gerwin
    Journal of Musculoskeletal Pain, Vol. 9(4) 2001; 81 – 93

    Hamstring tendonitis per se can be diagnosed by 3 tests:
    British Journal of Sports
    Br J Sports Med 2012;46:883-887
    Reliability and validity of three pain provocation tests used for the diagnosis of chronic proximal hamstring tendinopathy
    Angelo Cacchio1, Fabrizio Borra2, Gabriele Severini3, Andrea Foglia4, Frank Musarra5, Nicola Taddio6, Fosco De Paulis7

    – These tests should elicit significant pain
    1) Puranen–Orava (PO) test – stand up, put foot up 90 degrees on a table
    2) bent-knee stretch (BK) test – bent knee maximally stretched while lying down – then knee straightened
    3) modified bent-knee stretch (MBK) test. – do above test while holding heel and rapidly straightening knee.

    I suspect any hamstring issue would be bad with those tests.

    Pudental neuralgia is the classic can’t sit long condition:
    Diagnostic Criteria for Pudendal Neuralgia by Pudendal Nerve Entrapment (Nantes Criteria)
    Jean-Jacques Labat,1 Thibault Riant,2 Roger Robert,3 Ge´rard Amarenco,4
    Jean-Pascal Lefaucheur,5 and Je´roˆme Rigaud1
    Neurourology and Urodynamics DOI 10.1002/nau
    “All forms of pain accentuated by sitting tend to be attributed to pudendal neuralgia”

    I suspect tissue above the ishial tuberosity would be affected
    – the piriformis which is a huge pain generator given the sciatic nerve either goes through it of under it (search it on my site).
    – the obturator internus bursa above the ischail tuberosity

    One would wonder if the back was an issue as well.

    What to do?
    1) Consider not sitting for a period of time – have your work desk elevated so you can stand and stand on an anti-fatigue mat. I have a patient with prior scoliosis surgery – he never sits down.
    2) Look into cushions used by wheelchair victims – even gel or air filled ones
    Clinical Biomechanics 24 (2009) 558–563
    Comparative study of pressure distribution at the user-cushion interface with different cushions in a population with spinal cord injury q
    A. Gil-Agudo a,*, A. De la Peña-González a, A. Del Ama-Espinosa a, E. Pérez-Rizo a, E. Díaz-Domínguez a,b, A. Sánchez-Ramos

    “much effort has been dedicated to alleviating pressure under the ischial tuberosities, which has lead to the appearance of a wide variety of wheelchair cushion models …
    the dual compartment air cushion exhibited the best mechanical performance with regard to the distribution of pressures”

    3) oral anti-inflammatories
    4) surgical debridement of bursa which can now be done thru a scope

    I plan on writing a blog not on this but that could take some time…

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