This paper presents a survey of existing robotic systems for lower-limb rehabilitation. It is a general assumption that robotics will play an important role in therapy activities within rehabilitation treatment. In the last decade, the interest in the field has grown exponentially mainly due to the initial success of the early systems and the growing demand caused by increasing numbers of stroke patients and their associate rehabilitation costs. As a result, robot therapy systems have been developed worldwide for training of both the upper and lower extremities. This work reviews all current robotic systems to date for lower-limb rehabilitation, as well as main clinical tests performed with them, with the aim of showing a clear starting point in the field. It also remarks some challenges that current systems still have to meet in order to obtain a broad clinical and market acceptance. 1. Introduction Stroke is the third most frequent cause of death worldwide and the leading cause of permanent disability in the USA and Europe [1]. Neurological impairment after stroke frequently leads to hemiparesis or partial paralysis of one side of the body that affects the patient’s ability to perform activities of daily living (ADL) such as walking and eating. Physical therapy, involving rehabilitation, helps improve the lost functions [2, 3]. The goal of rehabilitation exercises is to perform specific movements that provoke motor plasticity to the patient and therefore improve motor recovery and minimize functional deficits. Movement rehabilitation is limb dependent, thus the affected limb has to be exercised [4]. This paper focuses on lower-limb rehabilitation. One-third of surviving patients from stroke do not regain independent walking ability and those ambulatory, walk in a typical asymmetric manner [1]. Rehabilitation therapies are critical to recover, and therefore many research is ongoing on the field. The rehabilitation process toward regaining a meaningful mobility can be divided into three phases [4–6]: (1) the bedridden patient is mobilized into the chair as soon as possible, (2) restoration of gait, and (3) improvement of gait (i.e., training of free walking if possible). Traditional rehabilitation therapies are very labor intensive especially for gait rehabilitation, often requiring more than three therapists together to assist manually the legs and torso of the patient to perform training. This fact imposes an enormous economic burden to any country’s health care system thus limiting its clinical acceptance. Furthermore, demographic change (aging),
References
[1]
D. Lloyd-Jones, R. J. Adams, T. M. Brown et al., “Heart disease and stroke statistics—2010 update: a report from the American heart association,” Circulation, vol. 121, no. 7, pp. e46–e215, 2010.
[2]
D. S. Smith, E. Goldenberg, A. Ashburn, et al., “Remedial therapy after stroke: a randomised controlled trial,” The British Medical Journal, vol. 282, no. 6263, pp. 517–520, 1981.
[3]
M. Dam, P. Tonin, S. Casson et al., “The effects of long-term rehabilitation therapy on poststroke hemiplegic patients,” Stroke, vol. 24, no. 8, pp. 1186–1191, 1993.
[4]
H. Schmidt, C. Werner, R. Bernhardt, S. Hesse, and J. Krüger, “Gait rehabilitation machines based on programmable footplates,” Journal of NeuroEngineering and Rehabilitation, vol. 4, article 2, 2007.
[5]
J. Carr and R. Shepherd, A Motor Relearning Program for Stroke, Aspen Publishers, 1987.
[6]
D. Y. L. Chan, C. C. H. Chan, and D. K. S. Au, “Motor relearning programme for stroke patients: a randomized controlled trial,” Clinical Rehabilitation, vol. 20, no. 3, pp. 191–200, 2006.
[7]
G. J. Gelderblom, M. De Wilt, G. Cremers, and A. Rensma, “Rehabilitation robotics in robotics for healthcare; a roadmap study for the European Commission,” in Proceedings of the IEEE International Conference on Rehabilitation Robotics, (ICORR '09), pp. 834–838, Kyoto, Japan, June 2009.
[8]
A. Wernig, S. Muller, A. Nanassy, and E. Cagol, “Laufband therapy based on “rules of spinal locomotion” is effective in spinal cord injured persons,” European Journal of Neuroscience, vol. 7, no. 4, pp. 823–829, 1995.
[9]
J. A. Galvez and D. J. Reinkensmeyer, “Robotics for gait training after spinal cord injury,” Topics in Spinal Cord Injury Rehabilitation, vol. 11, no. 2, pp. 18–33, 2005.
[10]
G. Colombo, M. Joerg, R. Schreier, and V. Dietz, “Treadmill training of paraplegic patients using a robotic orthosis,” Journal of Rehabilitation Research and Development, vol. 37, no. 6, pp. 693–700, 2000.
[11]
G. Colombo, M. Wirz, and V. Dietz, “Driven gait orthosis for improvement of locomotor training in paraplegic patients,” Spinal Cord, vol. 39, no. 5, pp. 252–255, 2001.
[12]
M. Wirz, D. H. Zemon, R. Rupp et al., “Effectiveness of automated locomotor training in patients with chronic incomplete spinal cord injury: a multicenter trial,” Archives of Physical Medicine and Rehabilitation, vol. 86, no. 4, pp. 672–680, 2005.
[13]
T. G. Hornby, D. H. Zemon, and D. Campbell, “Robotic-assisted, body-weight-supported treadmill training in individuals following motor incomplete spinal cord injury,” Physical Therapy, vol. 85, no. 1, pp. 52–66, 2005.
[14]
J. Hidler, D. Nichols, M. Pelliccio et al., “Multicenter randomized clinical trial evaluating the effectiveness of the Lokomat in subacute stroke,” Neurorehabilitation and Neural Repair, vol. 23, no. 1, pp. 5–13, 2009.
[15]
K. P. Westlake and C. Patten, “Pilot study of Lokomat versus manual-assisted treadmill training for locomotor recovery post-stroke,” Journal of NeuroEngineering and Rehabilitation, vol. 6, no. 1, article 18, 2009.
[16]
S. Freivogel, J. Mehrholz, T. Husak-Sotomayor, and D. Schmalohr, “Gait training with the newly developed “LokoHelp”-system is feasible for non-ambulatory patients after stroke, spinal cord and brain injury. A feasibility study,” Brain Injury, vol. 22, no. 7-8, pp. 625–632, 2008.
[17]
S. Freivogel, D. Schmalohr, and J. Mehrholz, “Improved walking ability and reduced therapeutic stress with an electromechanical gait device,” Journal of Rehabilitation Medicine, vol. 41, no. 9, pp. 734–739, 2009.
[18]
G. R. West, “Powered gait orthosis and method of utilizing same,” Patent number 6 689 075, 2004.
[19]
D. Reinkensmeyer, J. Wynne, and S. Harkema, “A robotic tool for studying locomotor adaptation and rehabilitation,” in Proceedings of the 2nd Joint Meeting of the IEEE Engineering in Medicine and Biology Society and the Biomedical Engineering Society, vol. 3, pp. 2013–2353, October 2002.
[20]
D. J. Reinkensmeyer, D. Aoyagi, J. L. Emken et al., “Tools for understanding and optimizing robotic gait training,” Journal of Rehabilitation Research and Development, vol. 43, no. 5, pp. 657–670, 2006.
[21]
J. L. Emken, S. J. Harkema, J. A. Beres-Jones, C. K. Ferreira, and D. J. Reinkensmeyer, “Feasibility of manual teach-and-replay and continuous impedance shaping for robotic locomotor training following spinal cord injury,” IEEE Transactions on Biomedical Engineering, vol. 55, no. 1, pp. 322–334, 2008.
[22]
S. K. Banala, S. K. Agrawal, and J. P. Scholz, “Active Leg Exoskeleton (ALEX) for gait rehabilitation of motor-impaired patients,” in Proceedings of the 10th IEEE International Conference on Rehabilitation Robotics, (ICORR '07), pp. 401–407, Noordwijk, The Netherlands, June 2007.
[23]
S. K. Banala, S. H. Kim, S. K. Agrawal, and J. P. Scholz, “Robot assisted gait training with active leg exoskeleton (ALEX),” IEEE Transactions on Neural Systems and Rehabilitation Engineering, vol. 17, no. 1, pp. 2–8, 2009.
[24]
J. F. Veneman, R. Kruidhof, E. E. G. Hekman, R. Ekkelenkamp, E. H. F. Van Asseldonk, and H. Van Der Kooij, “Design and evaluation of the Lopes exoskeleton robot for interactive gait rehabilitation,” IEEE Transactions on Neural Systems and Rehabilitation Engineering, vol. 15, no. 3, pp. 379–386, 2007.
[25]
E. van Asseldonk, C. Simons, M. Folkersman, et al., “Robot aided gait training according to the assist-as-needed principle in chonic stroke survivors,” in Proceedings of the Annual Meeting of the Society for Neuroscience (Poster), Chicago, Ill, USA, October 2009.
[26]
P. Beyl, M. van Damme, R. van Ham, R. Versluys, B. Vanderborght, and D. Lefeber, “An exoskeleton for gait rehabilitation: prototype design and control principle,” in Proceedings of the IEEE International Conference on Robotics and Automation, (ICRA '08), pp. 2037–2042, Pasadena, Calif, USA, May 2008.
[27]
M. Pietrusinski, I. Cajigas, Y. Mizikacioglu, M. Goldsmith, P. Bonato, and C. Mavroidis, “Gait rehabilitation therapy using robot generated force fields applied at the pelvis,” in Proceedings of the IEEE Haptics Symposium, (HAPTICS '10), pp. 401–407, Waltham, Mass, USA, March 2010.
[28]
D. Surdilovic and R. Bernhardt, “STRING-MAN: a new wire robot for gait rehabilitation,” in Proceedings of the IEEE International Conference on Robotics and Automation, vol. 2, pp. 2031–2036, May 2004.
[29]
S. Hesse and D. Uhlenbrock, “A mechanized gait trainer for restoration of gait,” Journal of Rehabilitation Research and Development, vol. 37, no. 6, pp. 701–708, 2000.
[30]
C. Werner, S. Von Frankenberg, T. Treig, M. Konrad, and S. Hesse, “Treadmill training with partial body weight support and an electromechanical gait trainer for restoration of gait in subacute stroke patients: a randomized crossover study,” Stroke, vol. 33, no. 12, pp. 2895–2901, 2002.
[31]
M. Pohl, C. Werner, M. Holzgraefe, et al., “Repetitive locomotor training and physiotherapy improve walking and basic activities of daily living after stroke: a single-blind, randomized multicentre trial(deutsche gangtrainerstudie, degas),” Clinical Rehabilitation, vol. 21, no. 1, pp. 17–27, 2007.
[32]
S. H. Peurala, O. Airaksinen, P. Huuskonen et al., “Effects of intensive therapy using gait trainer or floor walking exercises early after stroke,” Journal of Rehabilitation Medicine, vol. 41, no. 3, pp. 166–173, 2009.
[33]
H. Schmidt, “Hapticwalker—a novel haptic device for walking simulation,” in Proceedings of the EuroHaptics Conference, pp. 60–67, Munich, Germany, June 2004.
[34]
S. Hesse and C. Werner, “Connecting research to the needs of patients and clinicians,” Brain Research Bulletin, vol. 78, no. 1, pp. 26–34, 2009.
[35]
H. Yano, S. Tamefusa, N. Tanaka, H. Saitou, and H. Iwata, “Gait rehabilitation system for stair climbing and descending,” in Proceedings of the IEEE Haptics Symposium, (HAPTICS '10), pp. 393–400, Waltham, Mass, USA, March 2010.
[36]
S. Chen, Y. Wang, S. Li, G. Wang, Y. Huang, and X. Mao, “Lower limb rehabilitation robot,” in Proceedings of the ASME/IFToMM International Conference on Reconfigurable Mechanisms and Robots, (ReMAR '09), pp. 439–443, London, UK, June 2009.
[37]
J. Yoon, B. Novandy, C. H. Yoon, and K. J. Park, “A 6-DOF gait rehabilitation robot with upper and lower limb connections that allows walking velocity updates on various terrains,” IEEE/ASME Transactions on Mechatronics, vol. 15, no. 2, Article ID 5424007, pp. 201–215, 2010.
[38]
M. Peshkin, D. A. Brown, J. J. Santos-Munne et al., “KineAssist: a robotic overground gait and balance training device,” in Proceedings of the 9th IEEE International Conference on Rehabilitation Robotics, (ICORR '05), pp. 241–246, Evanston, Ill, USA, July 2005.
[39]
J. K. Burgess, G. C. Weibel, and D. A. Brown, “Overground walking speed changes when subjected to body weight support conditions for nonimpaired and post stroke individuals,” Journal of NeuroEngineering and Rehabilitation, vol. 7, no. 1, article 6, 2010.
[40]
M. Bouri, Y. Stauffer, C. Schmitt et al., “The walktrainer: a robotic system for walking rehabilitation,” in Proceedings of the IEEE International Conference on Robotics and Biomimetics, (ROBIO '06), pp. 1616–1621, Kunming, China, December 2006.
[41]
Y. Allemand and Y. Stauffer, “Overground gait rehabilitation: first clinical investigation with the walktrainer,” in Proceedings of the European Conference on Technically Assisted Rehabilitation, (TAR '09), Berlin, Germany, 2009.
[42]
A. Goffer, “Gait-locomotor apparatus,” US patent number 7 153 242, 2006.
[43]
H. Kawamoto and Y. Sankai, “Power assist system hal-3 for gait disorder person,” in Proceedings of the 8th International Conference on Computers Helping People with Special Needs, pp. 196–203, London, UK, 2002.
[44]
K. Suzuki, Y. Kawamura, T. Hayashi, T. Sakurai, Y. Hasegawa, and Y. Sankai, “Intention-based walking support for paraplegia patient,” in Proceedings of the International Conference on Systems, Man and Cybernetics, vol. 3, pp. 2707–2713, Hawaii, USA, October 2005.
[45]
H. Kawamoto, T. Hayashi, T. Sakurai, K. Eguchi, and Y. Sankai, “Development of single leg version of HAL for hemiplegia,” in Proceedings of the 31st Annual International Conference of the IEEE Engineering in Medicine and Biology Society, (EMBC '09), pp. 5038–5043, Minneapolis, Minn, USA, September 2009.
[46]
K. H. Seo and J. J. Lee, “The development of two mobile gait rehabilitation systems,” IEEE Transactions on Neural Systems and Rehabilitation Engineering, vol. 17, no. 2, Article ID 4785182, pp. 156–166, 2009.
[47]
C. Schmitt, P. Métrailler, A. Al-Khodairy, et al., “The motion maker: a rehabilitation system combining an orthosis with closed-loop electrical muscle stimulation,” in Proceedings of the 8th Vienna International Workshop on Functional Electrical Stimulation, pp. 117–120, Vienna, Austria, September 2004.
[48]
M. Bouri, B. Le Gall, and R. Clavel, “A new concept of parallel robot for rehabilitation and fitness: the Lambda,” in Proceedings of the IEEE International Conference on Robotics and Biomimetics, (ROBIO '09), pp. 2503–2508, Guilin, China, December 2009.
[49]
K. Homma, O. Fukuda, J. Sugawara, Y. Nagata, and M. Usuba, “A wire-driven leg rehabilitation system: development of a 4-dof experimental system,” in Proceedings of the International Conference on Advanced Intelligent Mechatronics, (IEEE/ASME '03), vol. 2, pp. 908–913, Piscataway, NJ, USA, July 2003.
[50]
P. Sui, L. Yao, Z. Lin, H. Yan, and J. S. Dai, “Analysis and synthesis of ankle motion and rehabilitation robots,” in Proceedings of the IEEE International Conference on Robotics and Biomimetics, (ROBIO '09), pp. 2533–2538, Guilin, China, December 2009.
[51]
M. Girone, G. Burdea, M. Bouzit, V. Popescu, and J. E. Deutsch, “Stewart platform-based system for ankle telerehabilitation,” Autonomous Robots, vol. 10, no. 2, pp. 203–212, 2001.
[52]
J. E. Deutsch, J. Latonio, G. C. Burdea, and R. Boian, “Post-stroke rehabilitation with the Rutgers Ankle system: a case study,” Presence: Teleoperators and Virtual Environments, vol. 10, no. 4, pp. 416–430, 2001.
[53]
R. Boian, C. Lee, J. Deutsch, G. Burdea, and J. Lewis, “Virtual realitybased system for ankle rehabilitation post stroke,” in Proceedings of the 1st International Workshop on Virtual Reality Rehabilitation, (VRMHR '02), pp. 77–86, Lausanne, Switzerland, November 2002.
[54]
J. E. Deutsch, J. A. Lewis, and G. Burdea, “Technical and patient performance using a virtual reality-integrated telerehabilitation system: preliminary finding,” IEEE Transactions on Neural Systems and Rehabilitation Engineering, vol. 15, no. 1, pp. 30–35, 2007.
[55]
R. Boian, M. Bouzit, G. Burdea, and J. Deutsch, “Dual stewart platform mobility simulator,” in Proceedings of the 26th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, (IEMBS '04), vol. 2, pp. 4848–4851, September 2004.
[56]
J. A. Saglia, N. G. Tsagarakis, J. S. Dai, and D. G. Caldwell, “A high-performance redundantly actuated parallel mechanism for ankle rehabilitation,” International Journal of Robotics Research, vol. 28, no. 9, pp. 1216–1227, 2009.
[57]
J. Nikitczuk, B. Weinberg, P. K. Canavan, and C. Mavroidis, “Active knee rehabilitation orthotic device with variable damping characteristics implemented via an electrorheological fluid,” IEEE/ASME Transactions on Mechatronics, vol. 15, no. 6, Article ID 5353649, pp. 952–960, 2010.
[58]
T. Kikuchi, K. Oda, and J. Furusho, “Leg-robot for demonstration of spastic movements of brain-injured patients with compact magnetorheological fluid clutch,” Advanced Robotics, vol. 24, no. 16, pp. 671–686, 2010.
[59]
J. Yoon and J. Ryu, “A novel reconfigurable ankle/foot rehabilitation robot,” in Proceedings of the IEEE International Conference on Robotics and Automation, (ICRA '05), pp. 2290–2295, Barcelona, Span, April 2005.
[60]
Y. Ding, M. Sivak, B. Weinberg, C. Mavroidis, and M. K. Holden, “NUVABAT: northeastern university virtual ankle and balance trainer,” in Proceedings of the IEEE Haptics Symposium, (HAPTICS '10), pp. 509–514, Waltham, Mass, USA, March 2010.
[61]
J. S. Dai, T. Zhao, and C. Nester, “Sprained ankle physiotherapy based mechanism synthesis and stiffness analysis of a robotic rehabilitation device,” Autonomous Robots, vol. 16, no. 2, pp. 207–218, 2004.
[62]
Y. H. Tsoi and S. Q. Xie, “Impedance control of ankle rehabilitation robot,” in Proceedings of the IEEE International Conference on Robotics and Biomimetics, (ROBIO '08), pp. 840–845, Bangkok, Thailand, February 2009.
[63]
C. C. K. Lin, M. S. Ju, S. M. Chen, and B. W. Pan, “A specialized robot for ankle rehabilitation and evaluation,” Journal of Medical and Biological Engineering, vol. 28, no. 2, pp. 79–86, 2008.
[64]
K. Homma and M. Usuba, “Development of ankle dorsiflexion/plantarflexion exercise device with passive mechanical joint,” in Proceedings of the 10th IEEE International Conference on Rehabilitation Robotics, (ICORR '07), pp. 292–297, Noordwijk, The Netherlands, June 2007.
[65]
D. P. Ferris, G. S. Sawicki, and A. R. Domingo, “Powered lower limb orthoses for gait rehabilitation,” Topics in Spinal Cord Injury Rehabilitation, vol. 11, no. 2, pp. 34–49, 2005.
[66]
B. J. Ruthenberg, N. A. Wasylewski, and J. E. Beard, “An experimental device for investigating the force and power requirements of a powered gait orthosis,” Journal of Rehabilitation Research and Development, vol. 34, no. 2, pp. 203–213, 1997.
[67]
G. Belforte, L. Gastaldi, and M. Sorli, “Pneumatic active gait orthosis,” Mechatronics, vol. 11, no. 3, pp. 301–323, 2001.
[68]
A. Roy, H. I. Krebs, S. L. Patterson et al., “Measurement of human ankle stiffness using the anklebot,” in Proceedings of the 10th IEEE International Conference on Rehabilitation Robotics, (ICORR '07), pp. 356–363, Noordwijk, The Netherlands, June 2007.
[69]
H. I. Krebs, L. Dipietro, S. Levy-Tzedek et al., “A paradigm shift for rehabilitation robotics,” IEEE Engineering in Medicine and Biology Magazine, vol. 27, no. 4, pp. 61–70, 2008.
[70]
I. Khanna, A. Roy, M. M. Rodgers, H. I. Krebs, R. M. MacKo, and L. W. Forrester, “Effects of unilateral robotic limb loading on gait characteristics in subjects with chronic stroke,” Journal of NeuroEngineering and Rehabilitation, vol. 7, no. 1, article 23, 2010.
[71]
J. A. Blaya and H. Herr, “Adaptive control of a variable-impedance ankle-foot orthosis to assist drop-foot gait,” IEEE Transactions on Neural Systems and Rehabilitation Engineering, vol. 12, no. 1, pp. 24–31, 2004.
[72]
A. Agrawal, S. K. Banala, S. K. Agrawal, and S. A. Binder-Macleod, “Design of a two degree-of-freedom ankle-foot orthosis for robotic rehabilitation,” in Proceedings of the 9th IEEE International Conference on Rehabilitation Robotics, (ICORR '05), pp. 41–44, July 2005.
[73]
G. S. Sawicki and D. P. Ferris, “A pneumatically powered knee-ankle-foot orthosis (kafo) with myoelectric activation and inhibition,” Journal of NeuroEngineering and Rehabilitation, vol. 6, p. 23, 2009.
[74]
D. P. Ferris, K. E. Gordon, G. S. Sawicki, and A. Peethambaran, “An improved powered ankle-foot orthosis using proportional myoelectric control,” Gait & Posture, vol. 23, no. 4, pp. 425–428, 2006.
[75]
K. Bharadwaj and T. G. Sugar, “Kinematics of a robotic gait trainer for stroke rehabilitation,” in Proceedings of the IEEE International Conference on Robotics and Automation, (ICRA '06), pp. 3492–3497, Orlando, Fla, USA, May 2006.
[76]
J. A. Ward, S. Balasubramanian, T. Sugar, and J. He, “Robotic gait trainer reliability and stroke patient case study,” in Proceedings of the10th IEEE International Conference on Rehabilitation Robotics, (ICORR '07), pp. 554–561, Noordwijk, The Netherlands, June 2007.
[77]
S. Hwang, J. Kim, J. Yi, K. Tae, K. Ryu, and Y. Kim, “Development of an active ankle foot orthosis for the prevention of foot drop and toe drag,” in Proceedings of the International Conference on Biomedical and Pharmaceutical Engineering, (ICBPE '06), pp. 418–423, Singapore, December 2006.
[78]
J. Y. Kim, S. J. Hwang, and Y. H. Kim, “Development of an active ankle-foot orthosis for hemiplegic patients,” in Proceedings of the 1st International Convention on Rehabilitation Engineering and Assistive Technology, (i-CREATe '07), pp. 110–113, New York, NY, USA, April 2007.
[79]
A. C. Satici, A. Erdogan, and V. Patoglu, “Design of a reconfigurable ankle rehabilitation robot and its use for the estimation of the ankle impedance,” in Proceedings of the IEEE International Conference on Rehabilitation Robotics, (ICORR '09), pp. 257–264, Kyoto, Japan, June 2009.
[80]
G. Sulter, C. Steen, and J. De Keyser, “Use of the barthel index and modified rankin scale in acute stroke trials,” Stroke, vol. 30, no. 8, pp. 1538–1541, 1999.
[81]
G. S. Sawicki, K. E. Gordon, and D. P. Ferris, “Powered lower limb orthoses: applications in motor adaptation and rehabilitation,” in Proceedings of the 9th IEEE International Conference on Rehabilitation Robotics, (ICORR '05), pp. 206–211, July 2005.
