Skip to main content
SpringerLink
Log in

Real-Time Finite Element Monitoring of Sub-Dermal Tissue Stresses in Individuals with Spinal Cord Injury: Toward Prevention of Pressure Ulcers

  • Published:
Annals of Biomedical Engineering Aims and scope Submit manuscript

Abstract

Patients with a spinal cord injury (SCI) are susceptible to deep tissue injury (DTI), a necrosis in excessively deformed muscle tissue overlying bony prominences, which, in wheelchair users, typically occurs in the gluteus muscles under the ischial tuberosities. Recently, we developed a generic real-time, subject-specific finite element (FE) modeling method to provide monitoring of mechanical conditions in deep tissues deformed between bony prominences and external surfaces. We previously employed this method to study internal tissue loads in plantar tissues of the foot [Yarnitzky, G., Z. Yizhar, and A. Gefen. J. Biomech. 39:2673–2689, 2006] and in muscle flaps of residual limbs in patients who underwent transtibial amputation (Portnoy, S., G. Yarnitzky, Z. Yizhar, A. Kristal, U. Oppenheim, I. Siev-Ner, and A. Gefen. Ann. Biomed. Eng. 35:120–135, 2007). The goal of the present study was to adapt the method to study the time-dependent mechanical stresses in glutei of patients with SCI during wheelchair sitting, continuously in real-time, and to compare the trends of internal tissue load data with those of controls. Prior to human studies, the real-time FE model—adapted to study the buttocks during sitting—was validated by comparing its predictions to data from a physical phantom of a buttocks and to non-real-time, commercial FE software. Next, real-time, subject-specific, FE models were built for six participating subjects (3 patients with SCI, 3 controls) based on their individual anatomies from MRI scans. Subjects were asked to sit normally in a wheelchair, on a ROHO cushion, and to watch a 90 min movie. Continuous interface pressure measurements from a pressure mat were used as subject-specific boundary conditions for real-time FE analyses of deep muscle stresses. Highest peaks of compression, shear and von Mises stresses throughout the trial period, and averages of peaks of these stresses were recorded over the trial for each individual. These parameters generally had 3-times to 5-times greater values in patients with SCI compared with controls. Likewise, stress doses, defined as the integration of peak compression stress over time, were ∼35-times and ∼50-times greater in the subjects with SCI, the values referring to the highest of all peaks recorded throughout the trial, and to average of peaks over the trial, respectively. We believe that by allowing—for the first time—practical and continuous monitoring of internal tissue loads in patients with motosensory deficits, without any risk or interruption to their lifestyle, and either at the clinical setting or at home, the present method can make a substantial contribution to the prevention of severe pressure ulcers and DTI.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
Figure 9

Similar content being viewed by others

References

  1. Agam L., A. Gefen 2007 Pressure ulcers and deep tissue injury: a bioengineering perspective. J. Wound Care 16:336–342

    PubMed  CAS  Google Scholar 

  2. Agam L., A. Gefen 2008 Toward real-time detection of the risk for a deep tissue injury in wheelchair users using the Hertz contact theory. J. Rehabil. Res. Dev. 45:537–550

    Article  PubMed  Google Scholar 

  3. Berkley J., G. Turkiyyah, D. Berg, M. Ganter, S. Weghorst 2004 Real-time finite element modeling for surgery simulation: An application to virtual suturing. IEEE T. Vis. Comput. Gr. 10:314–325. doi:10.1109/TVCG.2004.1272730

    Article  PubMed  Google Scholar 

  4. Berlowitz D. R., D. M. Brienza 2007 Are all pressure ulcers the result of deep tissue injury? A review of the literature. Osto. Wound Man. 53:34–38

    PubMed  Google Scholar 

  5. Black, J. Deep tissue injury: state of the science. In: 10th European Pressure Ulcer Advisory Panel Open Meeting, Oxford, UK, August 30–September 1, 2007.

  6. Black J. M. 2005 The National Pressure Ulcer Advisory Panel. Moving towards consensus on deep tissue injury and pressure ulcer staging. Adv. Skin Wound Care 18:415–421. doi:10.1097/00129334-200510000-00008

    Article  PubMed  Google Scholar 

  7. Black J., M. Baharestani, J. Cuddigan, B. Dorner, L. Edsberg, D. Langemo, M. E. Posthauer, C. Ratliff, G. Taler 2007 National Pressure Ulcer Advisory Panel. National Pressure Ulcer Advisory Panel’s updated pressure ulcer staging system. Dermatol. Nurs. 19:343–349

    PubMed  Google Scholar 

  8. Bland J. M., D. G. Altman 1986 Statistical methods for assessing agreement between two methods of clinical measurement. Lancet i: 307–310

    Google Scholar 

  9. Bliss M. R. 1992 Acute pressure area care: Sir James Paget’s legacy. Lancet 339:221–223. doi:10.1016/0140-6736(92)90016-V

    Article  PubMed  CAS  Google Scholar 

  10. Brosh T., M. Arcan 2000 Modeling the body/chair interaction—an integrative experimental-numerical approach. Clin. Biomech. 15: 217–219. doi:10.1016/S0268-0033(99)00073-X

    Article  CAS  Google Scholar 

  11. Drerup B., S. Kraneburg, A. Koller 2001 Visualisation of pressure dose: Synopsis of peak pressure, mean pressure, loading time and pressure time-integral. Clin. Biomech. 16:833–834

    Google Scholar 

  12. Ferrarin M., G. Andreoni, A. Pedotti 2000 Comparative biomechanical evaluation of different wheelchair seat cushions. J. Rehabil. Res. Dev. 37:315–324

    PubMed  CAS  Google Scholar 

  13. Gawlitta D., W. Li, C. W. Oomens, F. P. Baaijens, D. L. Bader, C. V. Bouten 2007 The relative contributions of compression and hypoxia to development of muscle tissue damage: an in vitro study. Ann Biomed Eng. 35:273–284. doi:10.1007/s10439-006-9222-5

    Article  PubMed  Google Scholar 

  14. Gefen A. 2007 The biomechanics of sitting-acquired pressure ulcers in patients with spinal cord injury or lesions. Int. Wound J. 4:222–231. doi:10.1111/j.1742-481X.2007.00330.x

    Article  PubMed  Google Scholar 

  15. Gefen A., L. H. Cornelissen, D. Gawlitta, D. L. Bader, C. W. Oomens 2008a The free diffusion of macromolecules in tissue-engineered skeletal muscle subjected to large compression strains. J. Biomech. 41:845–853. doi:10.1016/j.jbiomech.2007.10.023

    Article  PubMed  Google Scholar 

  16. Gefen A., N. Gefen, E. Linder-Ganz, S. S. Margulies 2005 In vivo muscle stiffening under bone compression promotes deep pressure sores. J. Biomech. Eng. 127:512–524. doi:10.1115/1.1894386

    Article  PubMed  CAS  Google Scholar 

  17. Gefen A., J. Levine 2007 The false premise in measuring body-support interface pressures for preventing serious pressure ulcers. J. Med. Eng. Tech. 31:375–380. doi:10.1080/03091900601165256

    Article  CAS  Google Scholar 

  18. Gefen A., B. van Nierop, D. L. Bader, C. W. Oomens 2008b Strain-time cell-death threshold for skeletal muscle in a tissue-engineered model system for deep tissue injury. J Biomech. 41:2003–2012. doi:10.1016/j.jbiomech.2008.03.039

    Article  PubMed  Google Scholar 

  19. Gilsdorf P., R. Patterson, S. Fisher 1991 Thirty-minute continuous sitting force measurements with different support surfaces in the spinal cord injured and able-bodied. J. Rehabil. Res. Dev. 28:33–38. doi:10.1682/JRRD.1991.10.0033

    Article  PubMed  CAS  Google Scholar 

  20. Hamanami K., A. Tokuhiro, H. Inoue 2004 Finding the optimal setting of inflated air pressure for a multi-cell air cushion for wheelchair patients with spinal cord injury. Acta. Med. Okayama 58:37–44

    PubMed  Google Scholar 

  21. Levi B., R. Rees 2007 Diagnosis and management of pressure ulcers. Clin Plast Surg. 34:735–748. doi:10.1016/j.cps.2007.07.007

    Article  PubMed  Google Scholar 

  22. Linder-Ganz E., S. Engelberg, M. Scheinowitz, A. Gefen 2006 Pressure-time cell death threshold for albino rat skeletal muscles as related to pressure sore biomechanics. J. Biomech. 39:2725–2732. doi:10.1016/j.jbiomech.2005.08.010

    Article  PubMed  Google Scholar 

  23. Linder-Ganz E., A. Gefen 2004 Mechanical compression-induced pressure sores in rat hind-limb: muscle stiffness, histology and computational models. J. Appl. Physiol. 96:2034–2049. doi:10.1152/japplphysiol.00888.2003

    Article  PubMed  CAS  Google Scholar 

  24. Linder-Ganz E., M. Scheinowitz, Z. Yizhar, S.S. Margulies, A. Gefen 2007 How do normals move during prolonged wheelchair-sitting? Technol Health Care 15: 195–202

    PubMed  CAS  Google Scholar 

  25. Linder-Ganz E., N. Shabshin, Y. Itzchak, A. Gefen 2007 Assessment of mechanical conditions in sub-dermal tissues during sitting: a combined experimental-MRI and finite element approach. J Biomech. 40:1443–1454. doi:10.1016/j.jbiomech.2006.06.020

    Article  PubMed  Google Scholar 

  26. Linder-Ganz E., N. Shabshin, Y. Itzchak, Z. Yizhar, I. Siev-Ner, A. Gefen 2008 Strains and stresses in sub-dermal tissues of the buttocks are greater in paraplegics than in healthy during sitting. J Biomech. 41:567–580. doi:10.1016/j.jbiomech.2007.10.011

    Article  PubMed  Google Scholar 

  27. Margolis D. J., J. Knauss, W. Bilker, M. Baumgarten 2003 Medical conditions as risk factors for pressure ulcers in an outpatient setting. Age Ageing 32:259–264. doi:10.1093/ageing/32.3.259

    Article  PubMed  Google Scholar 

  28. Merbitz C. T., R. B. King, J. Bleiberg, J. C. Grip 1985 Wheelchair push-ups: measuring pressure relief frequency. Arch. Phys. Med. Rehabil. 66:433–438

    PubMed  CAS  Google Scholar 

  29. Ohura T., N. Ohura, H. Oka 2007 Incidence and clinical symptoms of hourglass and sandwich-shaped tissue necrosis in stage IV pressure ulcers. Wounds 19:310–319

    Google Scholar 

  30. Oomens C. W., O. F. Bressers, E. M. Bosboom, C. V. Bouten, D. L. Bader 2003 Can loaded interface characteristics influence strain distributions in muscle adjacent to bony prominences? Comput. Met. Biomech. Biomed. Eng. 6:171–180. doi:10.1080/1025584031000121034

    Article  CAS  Google Scholar 

  31. Palevski A., I. Glaich, S. Portnoy, E. Linder-Ganz, A. Gefen 2006 Stress relaxation of porcine gluteus muscle subjected to sudden transverse deformation as related to pressure sore modeling. J. Biomech. Eng. 128: 782–787. doi:10.1115/1.2264395

    Article  PubMed  Google Scholar 

  32. Patterson R. P., S. V. Fisher 1980 Pressure and temperature patterns under ischial tuberosities. Bull. Prosthet. Res. 17:5–11

    Google Scholar 

  33. Portnoy S., G. Yarnitzky, Z. Yizhar, A. Kristal, U. Oppenheim, I. Siev-Ner, A. Gefen 2007 Real-time patient-specific finite element analysis of internal stresses in the soft tissues of a residual limb: a new tool for prosthetic fitting. Ann. Biomed. Eng. 35:120–135. doi:10.1007/s10439-006-9208-3

    Article  PubMed  CAS  Google Scholar 

  34. Ragan R., T. W. Kernozek, M. Bidar, J. W. Matheson 2002 Seat-interface pressures on various thicknesses of foam wheelchair cushions: a finite modeling approach. Arch. Phys. Med. Rehabil. 83:872–875. doi:10.1053/apmr.2002.32677

    Article  PubMed  Google Scholar 

  35. Salcido R. 2006 What is the “purple heel”? Adv. Skin Wound Care 19:11

    PubMed  Google Scholar 

  36. Shirado O., M. Kawase, A. Minami, T. E. Strax 2004 Quantitative evaluation of long sitting in paraplegic patients with spinal cord injury. Arch. Phys. Med. Rehabil. 85:1251–1256. doi:10.1016/j.apmr.2003.09.014

    Article  PubMed  Google Scholar 

  37. Stekelenburg A., C. W. Oomens, G. J. Strijkers, K. Nicolay, D. L. Bader 2006 Compression-induced deep tissue injury examined with magnetic resonance imaging and histology. J. Appl. Physiol. 100:1946–1954. doi:10.1152/japplphysiol.00889.2005

    Article  PubMed  CAS  Google Scholar 

  38. Stekelenburg A., G. J. Strijkers, H. Parusel, D. L. Bader, K. Nicolay, C. W. Oomens 2007 Role of ischemia and deformation in the onset of compression-induced deep tissue injury: MRI-based studies in a rat model. J Appl Physiol. 102:2002–2011. doi:10.1152/japplphysiol.01115.2006

    Article  PubMed  Google Scholar 

  39. Stockton L., D. Parker 2002 Pressure relief behavior and the prevention of pressure ulcers in wheelchair users in the community. J. Tissue. Viability 12:84–92

    PubMed  Google Scholar 

  40. Tam E. W., A. F. Mak, W. N. Lam, J. H. Evans, Y. Y. Chow 2003 Pelvic movement and interface pressure distribution during manual wheelchair propulsion. Arch. Phys. Med. Rehabil. 84:1466–1472. doi:10.1016/S0003-9993(03)00269-7

    Article  PubMed  Google Scholar 

  41. Temes W. C., P. Harder 1977 Pressure relief training device. Phys. Ther. 57:1152–1153

    PubMed  CAS  Google Scholar 

  42. Thomas, D. R. Prevention and treatment of pressure ulcers: what works? What doesn’t? Cleve. Clin. J. Med. 68:704–707, 10–14, 17–22, 2001.

    Google Scholar 

  43. Tsokos M., A. Heinemann, K. Puschel 2000 Pressure sores: epidemiology, medico-legal implications and forensic argumentation concerning causality. Int. J. Legal. Med. 113:283–287. doi:10.1007/s004149900125

    Article  PubMed  CAS  Google Scholar 

  44. Verver M. M., J. van Hoof, C. W. Oomens, J. S. Wismans, F. P. Baaijens 2004 A finite element model of the human buttocks for prediction of seat pressure distributions. Comput. Met. Biomech. Biomed. Eng. 7:193–203. doi:10.1080/10255840410001727832

    Article  CAS  Google Scholar 

  45. Wagnac E. L., C. E. Aubin, J. Dansereau 2008 A new method to generate a patient-specific finite element model of the human buttocks. IEEE Trans. Biomed. Eng. 55:774–783. doi:10.1109/TBME.2007.912640

    Article  PubMed  Google Scholar 

  46. Wey P. D., L. A. Casas, V. L. Lewis Jr 1990 Buried inferiorly based gluteus maximus musculocutaneous flap for reconstruction of large, recurrent ischiopubic pressure sores. Ann Plast Surg. 24:283–288. doi:10.1097/00000637-199003000-00016

    Article  PubMed  CAS  Google Scholar 

  47. Yarnitzky G., Z. Yizhar, A. Gefen 2006 Real-time subject-specific monitoring of internal deformations and stresses in the soft tissues of the foot: A new approach in gait analysis. J. Biomech. 39:2673–2689. doi:10.1016/j.jbiomech.2005.08.021

    Article  PubMed  CAS  Google Scholar 

Download references

Acknowledgments

We appreciate the help of Mr. Boaz Samir from ‘‘Zeadim’’ Daily Rehabilitation Center, Ramat-Gan, Israel, for his help in recruiting volunteers for this study. Ms. Sigal Portnoy, a doctoral student in the Musculoskeletal Biomechanics Laboratory (AG), Tel Aviv University, is thanked for her help in data analyses.

Author information

Authors and Affiliations

  1. Department of Biomedical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv, 69978, Israel

    Eran Linder-Ganz, Gilad Yarnitzky & Amit Gefen

  2. Department of Physical Therapy, Tel Aviv University, Tel Aviv, Israel

    Ziva Yizhar

  3. Department of Orthopedic Rehabilitation, Chaim Sheba Medical Center, Tel Hashomer, Israel

    Itzhak Siev-Ner

Authors
  1. Eran Linder-Ganz
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Gilad Yarnitzky
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Ziva Yizhar
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Itzhak Siev-Ner
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Amit Gefen
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Amit Gefen.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Linder-Ganz, E., Yarnitzky, G., Yizhar, Z. et al. Real-Time Finite Element Monitoring of Sub-Dermal Tissue Stresses in Individuals with Spinal Cord Injury: Toward Prevention of Pressure Ulcers. Ann Biomed Eng 37, 387–400 (2009). https://doi.org/10.1007/s10439-008-9607-8

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10439-008-9607-8

Keywords

Search

Navigation