Принципы оценки эффективности и безопасности использования экзоскелета у пациентов с параличами нижних конечностей (обзор)
В реабилитации больных, потерявших способность самостоятельно передвигаться из-за парализации нижних конечностей, перспективным направлением является использование экзоскелета. В последние годы разработано значительное число роботизированных устройств, улучшающих ходьбу лиц с нижним парапарезом. Однако сравнение между собой этих устройств затруднено из-за отсутствия стандартизированных подходов к оценке их эффективности и безопасности. В обзоре представлены сведения об общих принципах апробации внешних роботизированных устройств, проанализированы способы определения безопасности и удобства использования экзоскелета. Рассмотрены возможности оценки качественных и количественных показателей ходьбы в экзоскелете. Представлена характеристика опросников, стандартизированных тестов и биомеханических исследований, которые применяются при апробации экзоскелетных устройств у лиц с параличами нижних конечностей. Показаны возможные пути оценки энергозатрат при передвижении в экзоскелете. Обоснована необходимость разработки единой стратегии оценки ходьбы в экзоскелете.
- Huang V.S., Krakauer J.W. Robotic neurorehabilitation: a computational motor learning perspective. J Neuroeng Rehabil 2009; 6; 5, https://doi.org/10.1186/1743-0003-6-5.
- Panizzolo F.A., Galiana I., Asbeck A.T., Siviy C., Schmidt K., Holt K.G., Walsh C.J. A biologically-inspired multi-joint soft exosuit that can reduce the energy cost of loaded walking. J Neuroeng Rehabil 2016; 13(1): 43, https://doi.org/10.1186/s12984-016-0150-9.
- Galle S., Malcolm P., Derave W., De Clercq D. Enhancing performance during inclined loaded walking with a powered ankle-foot exoskeleton. Eur J Appl Physiol 2014; 114(11): 2341–2351, https://doi.org/10.1007/s00421-014-2955-1.
- Malcolm P., Derave W., Galle S., De Clercq D. A simple exoskeleton that assists plantarflexion can reduce the metabolic cost of human walking. PLoS One 2013; 8(2): e56137, https://doi.org/10.1371/journal.pone.0056137.
- Верейкин А.А., Ковальчук А.К., Кулаков Д.Б., Семенов С.Е. Анализ и выбор кинематической структуры исполнительного механизма экзоскелета. Наука и образование: научное издание МГТУ им. Н.Э. Баумана 2014; 7: 72–93, https://doi.org/10.7463/0714.0717676.
- Воробьев А. А., Андрющенко Ф.А., Засыпкина О.А., Соловьева И.О., Кривоножкина П.С., Поздняков А.М. Терминология и классификация экзоскелетов. Вестник Волгоградского государственного медицинского университета 2015; 3(55): 71–77.
- Chen G., Chan C.K., Guo Z., Yu H. A review of lower extremity assistive robotic exoskeletons in rehabilitation therapy. Crit Rev Biomed Eng 2013; 41(4–5): 343–363, https://doi.org/10.1615/critrevbiomedeng.2014010453.
- Brown-Triolo D.L., Roach M.J., Nelson K., Triolo R.J. Consumer perspectives on mobility: implications for neuroprosthesis design. J Rehabil Res Deve 2002; 39(6): 6569–669.
- Kobetic R., To C.S., Schnellenberger J.R., Audu M.L., Bulea T.C., Gaudio R., Pinault G., Tashman S., Triolo R.J. Development of hybrid orthosis for standing, walking, and stair climbing after spinal cord injury. J Rehabil Res Dev 2009; 46(3): 447–462.
- Schwartz I., Meiner Z. Robotic-assisted gait training in neurological patients: who may benefit? Ann Biomed Eng 2015; 43(5): 1260–1269, https://doi.org/10.1007/s10439-015-1283-x.
- Benson I., Hart K., Tussler D., van Middendorp J.J. Lower-limb exoskeletons for individuals with chronic spinal cord injury: findings from a feasibility study. Clin Rehabil 2016; 30(1): 73–84, https://doi.org/10.1177/0269215515575166.
- Aach M., Meindl R.C., Geßmann J., Schildhauer T.A., Citak M., Cruciger O. Exoskeletons for rehabilitation of patients with spinal cord injuries. Options and limitations. Unfallchirurg 2015; 118(2): 130–137, https://doi.org/10.1007/s00113-014-2616-1.
- Lajeunesse V., Vincent C., Routhier F., Careau E., Michaud F. Exoskeletons’ design and usefulness evidence according to a systematic review of lower limb exoskeletons used for functional mobility by people with spinal cord injury. Disabil Rehabil Assist Technol 2016; 11(7): 535–547, https://doi.org/1 0.3109/17483107.2015.1080766.
- Bortole M., Venkatakrishnan A., Zhu F., Moreno J.C., Francisco G.E., Pons J.L., Contreras-Vidal J.L. The H2 robotic exoskeleton for gait rehabilitation after stroke: early findings from a clinical study. J Neuroeng Rehabil 2015; 12: 54, https://doi.org/10.1186/s12984-015-0048-y.
- Fineberg D.B., Asselin P., Harel N.Y., Agranova-Breyter I., Kornfeld S.D., Bauman W.A., Spungen A.M. Vertical ground reaction force-based analysis of powered exoskeleton-assisted walking in persons with motor-complete paraplegia. J Spinal Cord Med 2013; 36(4): 313–321, https://doi.org/10.1179/2045772313y.0000000126.
- Ohta Y., Yano H., Suzuki R., Yoshida M., Kawashima N., Nakazawa K. A two-degree-of-freedom motor-powered gait orthosis for spinal cord injury patients. Proc Inst Mech Eng H 2007; 221: 629–639, https://doi.org/10.1243/09544119JEIM55.
- Suzuki K., Mito G., Kawamoto H., Hasegawa Y., Sankai Y. Intention-based walking support for paraplegia patients with Robot Suit HAL. In: Climbing and walking robots. InTech; 2010, https://doi.org/10.5772/8835.
- Hasegawa Y., Jang J., Sankai Y. Cooperative walk control of paraplegia patient and assistive system. IEEE International Conference on Intelligent Robots and Systems 2009; https://doi.org/10.1109/iros.2009.5354192.
- Kwa H.K., Noorden J.H., Missel M., Craig T., Pratt J.E., Neuhaus P.D. Development of the IHMC mobility assist exoskeleton. IEEE International Conference on Robotics and Automation 2009, https://doi.org/10.1109/robot.2009.5152394.
- Tsukahara A., Hasegawa Y., Sankai Y. Standing-up motion support for paraplegic patient with Robot Suit HAL. IEEE Int Conf Rehabil Robot 2009, https://doi.org/10.1109/icorr.2009.5209567.
- Tsukahara A., Kawanishi R., Hasegawa Y., Sankai Y. Sit-to-stand and stand-to-sit transfer support for complete paraplegic patients with Robot Suit HAL. Advanced Robotics 2010; 24(11): 1615–1638, https://doi.org/10.1163/016918610x512622.
- Neuhaus P.D., Noorden J.H., Craig T.J., Torres T., Kirschbaum J., Pratt J.E. Design and evaluation of Mina: a robotic orthosis for paraplegics. IEEE Int Conf Rehabil Robot 2011, https://doi.org/10.1109/ICORR.2011.5975468.
- Strausser K.A., Kazerooni H. The development and testing of a Human Machine Interface for a mobile medical exoskeleton. IEEE International Conference on Intelligent Robots and Systems 2011, https://doi.org/10.1109/iros.2011.6048674.
- Zeilig G., Weingarden H., Zwecker M., Dudkiesicz I., Bloch A., Esquenazi A. Safety and tolerance of the ReWalk™ exoskeleton suit for ambulation by people with complete spinal cord injury: a pilot study. J Spinal Cord Med 2012; 35(2): 96–101, https://doi.org/10.1179/2045772312Y.0000000003.
- Tamez-Duque J., Cobian-Ugalde R., Kilicarslan A., Venkatakrishnan A., Soto R., Contreras-Vidal J.L. Real-time strap pressure sensor system for powered exoskeletons. Sensors (Basel) 2015; 15(2): 4550–4563, https://doi.org/10.3390/s150204550.
- Ekelem A., Murray S., Goldfarb M. Preliminary assessment of variable geometry stair ascent and descent with a powered lower limb orthosis for individuals with paraplegia. Conf Proc IEEE Eng Med Biol Soc 2015; 2015: 4671–4674, https://doi.org/10.1109/EMBC.2015.7319436.
- Reza S.M., Ahmad N., Choudhury I.A., Ghazilla R.A. A fuzzy controller for lower limb exoskeletons during sit-to-stand and stand-to-sit movement using wearable sensors. Sensors (Basel) 2014; 14(3): 4342–4363, https://doi.org/10.3390/s140304342.
- Kim H., Lee J., Jang J., Park S., Han C. Design of an exoskeleton with minimized energy consumption based on using elastic and dissipative elements. International Journal of Control, Automation and Systems 2015; 13(2): 463–474, https://doi.org/10.1007/s12555-013-0386-0.
- Koller J.R. Jacobs D.A., Ferris D.P., Remy C.D. Learning to walk with an adaptive gain proportional myoelectric controller for a robotic ankle exoskeleton. J Neuroeng Rehabil 2015; 12: 97, https://doi.org/10.1186/s12984-015-0086-5.
- Goldfarb M., Korkowski K., Harrold B., Durfee W. Preliminary evaluation of a controlled-brake orthosis for FES-aided gait. IEEE Trans Neural Syst Rehabil Eng 2003; 11(3): 241–248, https://doi.org/10.1109/TNSRE.2003.816873.
- Belforte G., Eula G., Appendino S., Sirolli S. Pneumatic interactive gait rehabilitation orthosis: design and preliminary testing. Proc Inst Mech Eng H 2011; 225(2): 158–169.
- Long Y., Du Z.J., Wang W.D., Dong W. Robust sliding mode control based on GA optimization and CMAC compensation for lower limb exoskeleton. Appl Bionics Biomech 2016; 2016: 5017381, https://doi.org/10.1155/2016/5017381.
- Lonini L., Shawen N., Scanlan K., Rymer W.Z., Kording K.P., Jayaraman A. Accelerometry-enabled measurement of walking performance with a robotic exoskeleton: a pilot study. J Neuroeng Rehabil 2016; 13: 35, https://doi.org/10.1186/s12984-016-0142-9.
- Federici S., Meloni F., Bracalenti M., De Filippis M.L. The effectiveness of powered, active lower limb exoskeletons in neurorehabilitation: a systematic review. NeuroRehabilitation 2015; 37(3): 321–340, https://doi.org/10.3233/NRE-151265.
- Ha K.H., Murray S.A., Goldfarb M. An approach for the cooperative control of FES with a powered exoskeleton during level walking for persons with paraplegia. IEEE Trans Neural Syst Rehabil Eng 2016; 24(4): 455–466, https://doi.org/10.1109/TNSRE.2015.2421052.
- Nene A.V., Jennings S.J. Physiological cost index of paraplegic locomotion using the ORLAU ParaWalker. Paraplegia 1992; 30: 246–252, https://doi.org/10.1038/sc.1992.63.
- Harvey L.A., Davis G.M., Smith M.B., Engel S. Energy expenditure during gait using the walkabout and isocentric reciprocal gait orthoses in persons with paraplegia. Arch Phys Med Rehabil 1998; 79(8): 945–949, https://doi.org/10.1016/S0003-9993(98)90092-2.
- Winchester P., Carollo J.J., Habasevich R. Physiologic costs of reciprocal gait in FES assisted walking. Paraplegia 1994; 32(10): 680–686, https://doi.org/10.1038/sc.1994.110.
- Takahashi K.Z., Lewek M.D., Sawicki G.S. A neuromechanics-based powered ankle exoskeleton to assist walking post-stroke: a feasibility study. J Neuroeng Rehabil 2015; 12: 23, https://doi.org/10.1186/s12984-015-0015-7.
- Klose K.J., Jacobs P.L., Broton J.G., Guest R.S., Needham-Shropshire B.M., Lebwohl N., Nash M.S., Green B.A. Evaluation of a training program for persons with SCI paraplegia using the Parastep1 ambulation system: part 1. Ambulation performance and anthropometric measures. Arch Phys Med Rehabil 1997; 78: 789–793, https://doi.org/10.1016/s0003-9993(97)90188-x.
- Brissot R., Gallien P., Le Bot M.P., Beaubras A., Laisné D., Beillot J., Dassonville J. Clinical experience with functional electrical stimulation-assisted gait with Parastep in spinal cord-injured patients. Spine 2000; 25(4): 501–508, https://doi.org/10.1097/00007632-200002150-00018.
- Evans N., Hartigan C., Kandilakis C., Pharo E., Clesson I. Acute cardiorespiratory and metabolic responses during exoskeleton-assisted walking overground among persons with chronic spinal cord injury. Top Spinal Cord Inj Rehabil 2015; 21(2): 122–132, https://doi.org/10.1310/sci2102-122.
- Quintero H.A., Farris R.J., Goldfarb M. A method for the autonomous control of lower limb exoskeletons for persons with paraplegia. ASME J Med Devices 2012; 6(4): 041003, https://doi.org/10.1115/1.4007181.
- Jung J.Y., Park H., Yang H.D., Chae M. Brief biomechanical analysis on the walking of spinal cord injury patients with a lower limb exoskeleton robot. IEEE Int Conf Rehabil Robot 2013; 2013: 6650351, https://doi.org/10.1109/ICORR.2013.6650351.
- Fan Y., Yin Y. Active and progressive exoskeleton rehabilitation using multisource information fusion from EMG and force-position EPP. IEEE Trans Biomed Eng 2013; 60(12): 3314–3321, https://doi.org/10.1109/tbme.2013.2267741.
- Domingo A., Lam T. Reliability and validity of using the Lokomat to assess lower limb joint position sense in people with incomplete spinal cord injury. J Neuroeng Rehabil 2014; 11: 167, https://doi.org/10.1186/1743-0003-11-167.
- Farris R.J., Quintero H.A., Murray S.A., Ha K.H., Hartigan C., Goldfarb M. A preliminary assessment of legged mobility provided by a lower limb exoskeleton for persons with paraplegia. IEEE Trans Neural Syst Rehabil Eng 2014; 22(3): 482–490, https://doi.org/10.1109/tnsre.2013.2268320.
- Murray S.A., Ha K.H., Goldfarb M. An assistive controller for a lower-limb exoskeleton for rehabilitation after stroke, and preliminary assessment thereof. Conf Proc IEEE Eng Med Biol Soc 2014, 2014: 4083–4086, https://doi.org/10.1109/embc.2014.6944521.
- Murray S.A., Ha K.H., Hartigan C., Goldfarb M. An assistive control approach for a lower-limb exoskeleton to facilitate recovery of walking following stroke. IEEE Trans Neural Syst Rehabil Eng 2014; 1–1, https://doi.org/10.1109/tnsre.2014.2346193.
- Afschrift M., De Groote F., De Schutter J., Jonkers I. The effect of muscle weakness on the capability gap during gross motor function: a simulation study supporting design criteria for exoskeletons of the lower limb. BioMed Eng OnLine 2014; 13(1): 111, https://doi.org/10.1186/1475-925x-13-111.
- Esquenazi A., Talaty M., Packel A., Saulino M. The ReWalk powered exoskeleton to restore ambulatory function to individuals with thoracic-level motor-complete spinal cord injury. Am J Phys Med Rehabil 2012; 91(11): 911–921, https://doi.org/10.1097/phm.0b013e318269d9a3.
- Rukina N.N., Kuznetsov A.N., Borzikov V.V., Komkova O.V., Belova A.N. Surface electromyography: its role and potential in the development of exoskeleton (review). Sovremennye tehnologii v medicine 2016; 8(2): 109–118, https://doi.org/10.17691/stm2016.8.2.15.
- Создание научно-исследовательской лаборатории современных методов и робототехнических систем для улучшения среды обитания человека. URL: http://grant.rscf.ru/prjcard_int?14-39-00008.
- WMA Declaration of Helsinki — Ethical Principles for Medical Research Involving Human Subjects. URL: http://www.wma.net/en/30publications/10policies/b3/.
- del-Ama A.J., Gil-Agudo Ã, Pons J.L., Moreno J.C. Hybrid gait training with an overground robot for people with incomplete spinal cord injury: a pilot study. Front Hum Neurosci 2014; 8, https://doi.org/10.3389/fnhum.2014.00298.
- Aach M., Cruciger O., Sczesny-Kaiser M., Höffken O., Meindl R.Ch., Tegenthoff M., Schwenkreis P., Sankai Y., Schildhauer T.A. Voluntary driven exoskeleton as a new tool for rehabilitation in chronic spinal cord injury: a pilot study. Spine J 2014; 14(12): 2847–2853, https://doi.org/10.1016/j.spinee.2014.03.042.
- Heinemann A. Relationships between impairment and physical disability as measured by the functional independence measure. Arch Phys Med Rehabil 1993; 74(6): 566–573, https://doi.org/10.1016/0003-9993(93)90153-2.
- Dodds T. A validation of the functional independence measurement and its performance among rehabilitation inpatients. Arch Phys Med Rehabil 1993; 74(5): 531–536, https://doi.org/10.1016/0003-9993(93)90119-u.
- Wade D.T. Measurement in neurological rehabilitation. Oxford University Press; 1992.
- Field-Fote E.C., Fluet G.G., Schafer S.D., Schneider E.M., Smith R., Downey P.A., Ruhl C.D. The spinal cord injury functional ambulation inventory (SCI-FAI). J Rehabil Med 2001; 33(4): 177–181, https://doi.org/10.1080/165019701750300645.
- Perry J., Garrett M., Gronley J.K., Mulroy S.J. Classification of walking handicap in the stroke population. Stroke 1995; 26(6): 982–989, https://doi.org/10.1161/01.str.26.6.982.
- Audu M.L., To C.S., Kobetic R., Triolo R.J. Gait evaluation of a novel hip constraint orthosis with implication for walking in paraplegia. IEEE Trans Neural Syst Rehabil Eng 2010; 18(6): 610–618, https://doi.org/10.1109/tnsre.2010.2047594.
- Shamaei K., Cenciarini M., Adams A.A., Gregorczyk K.N., Schiffman J.M., Dollar A.M. Design and evaluation of a quasi-passive knee exoskeleton for investigation of motor adaptation in lower extremity joints. IEEE Trans Biomed Eng 2014; 61(6): 1809–1821, https://doi.org/10.1109/tbme.2014.2307698.
- Mizrahi J., Braun Z., Najenson T., Graupe D. Quantitative weightbearing and gait evaluation of paraplegics using functional electrical stimulation. Med Biol Eng Comput 1985; 23(2): 101–107, https://doi.org/10.1007/bf02456745.
- Braun Z., Mizrahi J., Najenson T., Graupe D. Activation of paraplegic patients by functional electrical stimulation: training and biomechanical evaluation. Scand J Rehabil Med Suppl 1985; 12: 93–101.
- Isakov E., Mizrahi J., Najenson T. Biomechanical and physiological evaluation of FES-activated paraplegic patients. J Rehabil Res Develop 1986; 23(3): 9–19.
- Sylos-Labini F., La Scaleia V., d’Avella A., Pisotta I., Tamburella F., Scivoletto G., Molinari M., Wang S., Wang L., van Asseldonk E., van der Kooij H., Hoellinger T., Cheron G., Thorsteinsson F., Ilzkovitz M., Gancet J., Hauffe R., Zanov F., Lacquaniti F., Ivanenko Y.P. EMG patterns during assisted walking in the exoskeleton. Front Hum Neurosci 2014; 8: 423, https://doi.org/10.3389/fnhum.2014.00423.
- Krishnan C., Washabaugh E.P., Seetharaman Y. A low cost real-time motion tracking approach using webcam technology. J Biomech 2015; 48(3): 544–548, https://doi.org/10.1016/j.jbiomech.2014.11.048.
- Simon S.R. Quantification of human motion: gait analysis — benefits and limitations to its application to clinical problems. J Biomech 2004; 37(12): 1869–1680, https://doi.org/10.1016/j.jbiomech.2004.02.047.
- Скворцов Д.В. Методика исследования кинематики движений и современные стандарты. Видеоанализ. Лечебная физкультура и спортивная медицина 2012; 12: 4–10.
- Lawson B.E., Huff A., Goldfarb M. A preliminary investigation of powered prostheses for improved walking biomechanics in bilateral transfemoral amputees. Conf Proc IEEE Eng Med Biol Soc 2012, https://doi.org/10.1109/embc.2012.6346884.
- Kent J., Franklyn-Miller A. Biomechanical models in the study of lower limb amputee kinematics: a review. Prosthet Orthot Int 2011; 35(2): 124–139, https://doi.org/10.1177/0309364611407677.
- Lam T., Wirz M., Lunenburger L., Dietz V. Swing phase resistance enhances flexor muscle activity during treadmill locomotion in incomplete spinal cord injury. Neurorehabil Neural Repair 2008; 22(5): 438–446, https://doi.org/10.1177/1545968308315595.
- Van Asseldonk E.H.F., Veneman J.F., Ekkelenkamp R., Buurke J.H., van der Helm F.C.T., van der Kooij H. The effects on kinematics and muscle activity of walking in a robotic gait trainer during zero-force control. IEEE Trans Neural Syst Rehabil Eng 2008; 16(4): 360–370, https://doi.org/10.1109/tnsre.2008.925074.
- Moreno J.C., Barroso F., Farina D., Gizzi L., Santos C., Molinari M., Pons J.L. Effects of robotic guidance on the coordination of locomotion. J Neuroeng Rehabil 2013; 10(1): 79, https://doi.org/10.1186/1743-0003-10-79.
- Fleerkotte B.M., Koopman B., Buurke J.H., van Asseldonk E.H.F., van der Kooij H., Rietman J.S. The effect of impedance-controlled robotic gait training on walking ability and quality in individuals with chronic incomplete spinal cord injury: an explorative study. J Neuroeng Rehabil 2014; 11(1): 26, https://doi.org/10.1186/1743-0003-11-26.
- Podsiadlo D., Richardson S. The timed “Up & Go”: a test of basic functional mobility for frail elderly persons. J Am Geriatr Soc 1991; 39(2): 142–148, https://doi.org/10.1111/j.1532-5415.1991.tb01616.x.
- Morris S., Morris M.E., Iansek R. Reliability of measurements obtained with the timed “Up & Go” test in people with Parkinson disease. Phys Ther 2001; 81(2): 810–818.
- Schoppen T., Boonstra A., Groothoff J.W., de Vries J., Göeken L.N.H., Eisma W.H. The timed “up and go” test: reliability and validity in persons with unilateral lower limb amputation. Arch Phys Med Rehabil 1999; 80(7): 825–828, https://doi.org/10.1016/s0003-9993(99)90234-4.
- Shumway-Cook A., Brauer S., Woollacott M. Predicting the probability for falls in community-dwelling older adults using the Timed Up & Go test. Phys Ther 2000; 80(9): 896–903.
- Rossier P., Wade D.T. Validity and reliability comparison of 4 mobility measures in patients presenting with neurologic impairment. Arch Phys Med Rehabil 2001; 82(1): 9–13, https://doi.org/10.1053/apmr.2001.9396.
- Smith M.T., Baer G.D. Achievement of simple mobility milestones after stroke. Arch Phys Med Rehabil 1999; 80(4): 442–447, https://doi.org/10.1016/s0003-9993(99)90283-6.
- Van Hedel H.J., Wirz M., Dietz V. Assessing walking ability in subjects with spinal cord injury: validity and reliability of 3 walking tests. Arch Phys Med Rehabil 2005; 86(2): 190–196, https://doi.org/10.1016/j.apmr.2004.02.010.
- Roomi J., Johnson M.M., Waters K., Yohannes A., Helm A., Connolly M.J. Respiratory rehabilitation, exercise capacity and quality of life in chronic airways disease in old age. Age Ageing 1996; 25(1): 12–16, https://doi.org/10.1093/ageing/25.1.12.
- Eng J.J., Chu K.S., Dawson A.S., Kim C.M., Hepburn K.E. Functional walk tests in individuals with stroke: relation to perceived exertion and myocardial exertion. Stroke 2002; 33(3): 756–761, https://doi.org/10.1161/hs0302.104195.
- Harada N.D., Chiu V., Stewart A.L. Mobility-related function in older adults: assessment with a 6-minute walk test. Arch Phys Med Rehabil 1999; 80(7): 837–841, https://doi.org/10.1016/s0003-9993(99)90236-8.
- Van Hedel H.J.A., Wirz M., Dietz V. Standardized assessment of walking capacity after spinal cord injury: the European network approach. Neurol Res 2008; 30(1): 61–73, https://doi.org/10.1179/016164107x230775.
- Buckley J.G., Spence W.D., Solomonidis S.E. Energy cost of walking: Comparison of “intelligent prosthesis” with conventional mechanism. Arch Phys Med Rehabil 1997; 78(3): 330–333, https://doi.org/10.1016/s0003-9993(97)90044-7.
- Orendurff M.S., Segal A.D., Klute G.K., McDowell M.L., Pecoraro J.A., Czerniecki J.M. Gait efficiency using the C-Leg. J Rehabil Res Dev 2006; 43(2): 239, https://doi.org/10.1682/jrrd.2005.06.0095.
- Seymour R., Engbretson B., Kott K., Ordway N., Brooks G., Crannell J., Hickernell E., Wheeler K. Comparison between the C-leg® microprocessor-controlled prosthetic knee and non-microprocessor control prosthetic knees: a preliminary study of energy expenditure, obstacle course performance, and quality of life survey. Prosthetics and Orthotics International 2007; 31(1): 51–61, https://doi.org/10.1080/03093640600982255.
- Chin T., Sawamura S., Shiba R., Oyabu H., Nagakura Y., Nakagawa A. Energy expenditure during walking in amputees after disarticulation of the hip. A microprocessor-controlled swing-phase control knee versus a mechanical-controlled stance-phase control knee. J Bone Joint Surg Br 2005; 87(1): 117–119.
- Datta D., Heller B., Howitt J. A comparative evaluation of oxygen consumption and gait pattern in amputees using Intelligent Prostheses and conventionally damped knee swing-phase control. Clin Rehabil 2005; 19(4): 398–403, https://doi.org/10.1191/0269215505cr805oa.
- Schmalz T., Blumentritt S., Jarasch R. Energy expenditure and biomechanical characteristics of lower limb amputee gait. Gait Posture 2002; 16(3): 255–263, https://doi.org/10.1016/s0966-6362(02)00008-5.
- Kaufman K.R., Levine J.A., Brey R.H., McCrady S.K., Padgett D.J., Joyner M.J. Energy expenditure and activity of transfemoral amputees using mechanical and microprocessor-controlled prosthetic knees. Arch Phys Med Rehabil 2008; 89(7): 1380–1385, https://doi.org/10.1016/j.apmr.2007.11.053.
- Hood V.L., Granat M.H., Maxwell D.J., Hasler J.P. A new method of using heart rate to represent energy expenditure: the total heart beat index. Arch Phys Med Rehabil 2002; 83(9): 1266–1273, https://doi.org/10.1053/apmr.2002.34598.
- MacGregor J. The objective measurement of physical performance with long term ambulatory physiological surveillance equipment (LAPSE). In: Proceedings of 3rd International Symposium on Ambulatory Monitoring. Stott F.D., Raftery E.B., Goulding L. (editors). London, UK: Academic Press; 1979; p. 29–39.
- Bailey M.J., Ratcliffe C.M. Reliability of physiological cost index measurements in walking normal subjects using steady-state, non-steady-state and post-exercise heart rate recording. Physiotherapy 1995; 81(10): 618–623, https://doi.org/10.1016/s0031-9406(05)66648-5.
- Chin T., Sawamura S., Fujita H., Nakajima S., Ojima I., Oyabu H., Nagakura Y., Otsuka H., Nakagawa A. The efficacy of physiological cost index (PCI) measurement of a subject walking with an Intelligent Prosthesis. Prosthet Orthot Int 1999; 23(1): 45–49.
- Nene A. Physiological cost index of walking in able-bodied adolescents and adults. Clin Rehabil 1993; 7(4): 319–326, https://doi.org/10.1177/026921559300700408.