Effortlessly performing activities of daily living constitutes a cornerstone of our personal independence. Naturally, various forms of upper limb impairments can have a substantial impact on quality of life. We developed the Myoshirt, a textile-based soft wearable robot, or exomuscle, that autonomously follows the user’s movements and thereby assists the shoulder against gravity. With the Myoshirt, participants without impairments (n = 10, 5 male) experienced a delayed onset of muscular fatigue by 51.1 s (36.1%, P < 0.001), while during a functional task their muscular activity decreased by 49.1% (P < 0.001). Analogously, two participants with upper limb impairments due to a muscular dystrophy and a spinal cord injury experienced a delayed onset of muscular fatigue during unloaded arm lifts by 256.4 s (61.5%) and by 450.6 s (210.3%), respectively. Our evidence suggests that the Myoshirt is an effective tool that intuitively assists the shoulder during functional reaching tasks, with the potential of increasing the personal independence of people with upper limb impairments.
This is a preview of subscription content, access via your institution
Access Nature and 54 other Nature Portfolio journals
Get Nature+, our best-value online-access subscription
$29.99 / 30 days
cancel any time
Subscribe to this journal
Receive 12 digital issues and online access to articles
$119.00 per year
only $9.92 per issue
Rent or buy this article
Prices vary by article type
Prices may be subject to local taxes which are calculated during checkout
Gassert, R. & Dietz, V. Rehabilitation robots for the treatment of sensorimotor deficits: a neurophysiological perspective. J. Neuroeng. Rehabil. 15, 46 (2018).
Weber, L. M. & Stein, J. The use of robots in stroke rehabilitation: a narrative review. NeuroRehabilitation 43, 99–110 (2018).
Mehrholz, J., Thomas, S., Kugler, J., Pohl, M. & Elsner, B. Electromechanical-assisted training for walking after stroke. Cochrane Database Syst. Rev. 2020, CD006185 (2020).
Mehrholz, J., Pohl, M., Platz, T., Kugler, J. & Elsner, B. Electromechanical and robot-assisted arm training for improving activities of daily living, arm function, and arm muscle strength after stroke. Cochrane Database Syst. Rev. 2018, CD006876 (2018).
Nef, T., Guidali, M. & Riener, R. ARMin III—arm therapy exoskeleton with an ergonomic shoulder actuation. Appl. Bionics Biomech. 6, 127–142 (2009).
Keller, U., Van Hedel, H. J. A., Klamroth-Marganska, V. & Riener, R. ChARMin: the first actuated exoskeleton robot for pediatric arm rehabilitation. IEEE/ASME Trans. Mechatron. 21, 2201–2213 (2016).
Hayward, K. S., Neibling, B. A. & Barker, R. N. Self-administered, home-based SMART (Sensorimotor Active Rehabilitation Training) arm training: a single-case report. Am. J. Occup. Ther. 69, 6904210020 (2015).
Xiloyannis, M. et al. Soft robotic suits: state of the art, core technologies and open challenges. IEEE Trans. Robot. https://doi.org/10.1109/TRO.2021.3084466 (2021).
Simpson, C. S., Okamura, A. M. & Hawkes, E. W. Exomuscle: an inflatable device for shoulder abduction support. In Proc. IEEE International Conference on Robotics and Automation (ICRA) 6651–6657 (2017); https://doi.org/10.1109/ICRA.2017.7989785
Simpson, C. et al. Upper extremity exomuscle for shoulder abduction support. IEEE Trans. Med. Robot. Bionics 2, 474–484 (2020).
Veeger, H. E. J. & van der Helm, F. C. T. Shoulder function: the perfect compromise between mobility and stability. J. Biomech. 40, 2119–2129 (2007).
Inman, V. T., Saunders, J. B. & Abbott, L. C. Observations on the function of the shoulder joint. J. Bone Jt Surg. 26, 1–30 (1944).
Sukal, T. M., Ellis, M. D. & Dewald, J. P. A. Shoulder abduction-induced reductions in reaching work area following hemiparetic stroke: neuroscientific implications. Exp. Brain Res. 183, 215–223 (2007).
Ellis, M. D., Sukal-Moulton, T. & Dewald, J. P. A. Progressive shoulder abduction loading is a crucial element of arm rehabilitation in chronic stroke. Neurorehabilit. Neural Repair 23, 862–869 (2009).
Prange, G. B. et al. Influence of gravity compensation on muscle activation patterns during different temporal phases of arm movements of stroke patients. Neurorehabilit. Neural Repair 23, 478–485 (2009).
Perry, B., Sivak, J. & Stokic, D. Providing unloading by exoskeleton improves shoulder flexion performance after stroke. Exp. Brain Res. 239, 1539–1549 (2021).
Kesner, S. B., Jentoft, L., Hammond, F. L. III, Howe, R. D. & Popovic, M. Design considerations for an active soft orthotic system for shoulder rehabilitation. In 2011 Annual International Conference of the IEEE Engineering in Medicine and Biology Society 8130–8134 (IEEE, 2011).
Galiana, I., Hammond, F. L. III, Howe, R. D. & Popovic, M. Wearable soft robotic device for post-stroke shoulder rehabilitation: identifying misalignments. In 2012 IEEE/RSJ International Conference on Intelligent Robots and Systems 317–322 (IEEE, 2012).
Lessard, S. et al. CRUX: a compliant robotic upper-extremity exosuit for lightweight, portable, multi-joint muscular augmentation. In 2017 International Conference on Rehabilitation Robotics (ICORR) 1633–1638 (IEEE, 2017).
Li, N. et al. Bio-inspired upper limb soft exoskeleton to reduce stroke-induced complications. Bioinspir. Biomim. 13, 66001 (2018).
Lessard, S. et al. A soft exosuit for flexible upper-extremity rehabilitation. IEEE Trans. Neural Syst. Rehabil. Eng. 26, 1604–1617 (2018).
Samper-Escudero, J. L., Gimenez, A., Sanchez-Uran, M. A. & Ferre, M. A cable-driven exosuit for upper limb flexion based on fibres compliance. IEEE Access 8, 153297–153310 (2020).
Natividad, R. F. & Yeow, C. H. Development of a soft robotic shoulder assistive device for shoulder abduction. In 2016 6th IEEE International Conference on Biomedical Robotics and Biomechatronics (BioRob) 989–993 (IEEE, 2016).
O’Neill, C. T., Phipps, N. S., Cappello, L., Paganoni, S. & Walsh, C. J. A soft wearable robot for the shoulder: design, characterization, and preliminary testing. IEEE Int. Conf. Rehabil. Robot. 02129, 1672–1678 (2017).
Georgarakis, A. M., Wolf, P. & Riener, R. Simplifying exosuits: kinematic couplings in the upper extremity during daily living tasks. In 2019 IEEE 16th International Conference on Rehabilitation Robotics (ICORR) 423–428 (IEEE, 2019).
Zhou, Y. M., Hohimer, C., Proietti, T., O’Neill, C. T. & Walsh, C. J. Kinematics-based control of an inflatable soft wearable robot for assisting the shoulder of industrial workers. IEEE Robot. Autom. Lett. 6, 2155–2162 (2021).
Proietti, T. et al. Sensing and control of a multi-joint soft wearable robot for upper-limb assistance and rehabilitation. IEEE Robot. Autom. Lett. 6, 2381–2388 (2021).
Georgarakis, A. M., Song, J., Wolf, P., Riener, R. & Xiloyannis, M. Control for gravity compensation in tendon-driven upper limb exosuits. In 2020 8th IEEE RAS/EMBS International Conference for Biomedical Robotics and Biomechatronics (BioRob) 340–345 (IEEE, 2020).
Wu, G. et al. ISB recommendation on definitions of joint coordinate systems of various joints for the reporting of human joint motion—part II: Shoulder, elbow, wrist and hand. J. Biomech. 38, 981–992 (2005).
Gaponov, I., Popov, D., Lee, S. J. & Ryu, J. Auxilio: a portable cable-driven exosuit for upper extremity assistance. Int. J. Control Autom. Syst. 15, 73–84 (2016).
O’Neill, C. T. et al. Inflatable soft wearable robot for reducing therapist fatigue during upper extremity rehabilitation in severe stroke. IEEE Robot. Autom. Lett. 5, 3899–3906 (2020).
Yozbatiran, N., Der-Yeghiaian, L. & Cramer, S. C. A standardized approach to performing the action research arm test. Neurorehabilit. Neural Repair 22, 78–90 (2008).
Stern, E. B. Stability of the Jebsen–Taylor Hand Function Test across three test sessions. Am. J. Occup. Ther. 46, 647–649 (1991).
Bemben, M. G. Age-related alterations in muscular endurance. Sports Med. 25, 259–269 (1998).
Merletti, R., Knaflitz, M. & De Luca, C. J. Myoelectric manifestations of fatigue in voluntary and electrically elicited contractions. J. Appl. Physiol. 69, 1810–1820 (1990).
Burden, A. in Biomechanical Evaluation of Movement in Sport and Exercise (eds Payton, C. J. & Burden, A.) 273–310 (Wiley, 2017); https://doi.org/10.4324/9780203095546-7
Gates, D. H., Walters, L. S., Cowley, J., Wilken, J. M. & Resnik, L. Range of motion requirements for upper-limb activities of daily living. Am. J. Occup. Ther. 70, 7001350010 (2015).
Brooke, M. H. et al. Clinical trial in Duchenne dystrophy. I. The design of the protocol. Muscle Nerve 4, 186–197 (1981).
Borg, G. A. V. Psychophysical bases of perceived exertion. Med. Sci. Sports Exerc. 14, 377–381 (1982).
Balasubramanian, S., Melendez-Calderon, A. & Burdet, E. A robust and sensitive metric for quantifying movement smoothness. IEEE Trans. Biomed. Eng. 59, 2126–2136 (2012).
Kim, J. et al. Reducing the metabolic rate of walking and running with a versatile, portable exosuit. Science 365, 668–672 (2019).
Ding, Y., Kim, M., Kuindersma, S. & Walsh, C. J. Human-in-the-loop optimization of hip assistance with a soft exosuit during walking. Sci. Robot. 3, eaar5438 (2018).
Lotti, N. et al. Adaptive model-based myoelectric control for a soft wearable arm exosuit: a new generation of wearable robot control. IEEE Robot. Autom. Mag. 27, 43–53 (2020).
Hosseini, M. et al. A sEMG-driven soft exosuit based on twisted string actuators for elbow assistive applications. IEEE Robot. Autom. Lett. 5, 4094–4101 (2020).
Park, D. & Cho, K. J. Development and evaluation of a soft wearable weight support device for reducing muscle fatigue on shoulder. PLoS ONE 12, e0173730 (2017).
Kim, S. et al. Assessing the influence of a passive, upper extremity exoskeletal vest for tasks requiring arm elevation: part I—“Expected” effects on discomfort, shoulder muscle activity, and work task performance. Appl. Ergon. 70, 315–322 (2018).
Kim, S. et al. Assessing the influence of a passive, upper extremity exoskeletal vest for tasks requiring arm elevation: part II—“Unexpected” effects on shoulder motion, balance, and spine loading. Appl. Ergon. 70, 323–330 (2018).
Gemperle, F., Kasabach, C., Stivoric, J., Bauer, M. & Martin, R. Design for wearability. In Digest of Papers. Second International Symposium on Wearable Computers (Cat. No.98EX215) 116–122 (IEEE, 1998); https://doi.org/10.1109/ISWC.1998.729537
Koo, S. H. Design factors and preferences in wearable soft robots for movement disabilities. Int. J. Cloth. Sci. Technol. 30, 477–495 (2018).
Myers, M. & Steudel, K. Effect of limb mass and its distribution on the energetic cost of running. J. Exp. Biol. 116, 363–373 (1985).
Lee, G. et al. Improved assistive profile tracking of soft exosuits for walking and jogging with off-board actuation. In 2017 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS) 1699–1706 (IEEE, 2017).
Xiloyannis, M., Chiaradia, D., Frisoli, A. & Masia, L. Physiological and kinematic effects of a soft exosuit on arm movements. J. Neuroeng. Rehabil. 16, 29 (2019).
Johnston, T. B. The movements of the shoulder joint—a plea for the use of the ‘plane of the scapula’ as the plane of reference for movements occurring at the humero-scapular joint. Br. J. Surg. 25, 252–260 (1937).
Levin, M. F., Liebermann, D. G., Parmet, Y. & Berman, S. Compensatory versus noncompensatory shoulder movements used for reaching in stroke. Neurorehabilit. Neural Repair 30, 635–646 (2016).
Merletti, R. & Parker, P. J. Electromyography: Physiology, Engineering, and Non-Invasive Applications (Wiley, 2004).
Haufe, F. L., Wolf, P., Riener, R. & Grimmer, M. Biomechanical effects of passive hip springs during walking. J. Biomech. 98, 109432 (2020).
Haufe, F. L., Kober, A. M., Wolf, P., Riener, R. & Xiloyannis, M. Learning to walk with a wearable robot in 880 simple steps: a pilot study on motor adaptation. J. Neuroeng. Rehabil. 18, 157 (2021).
Georgarakis, A.-M., Xiloyannis, M., Wolf, P. & Riener, R. The Myoshirt data repository. Zenodo https://doi.org/10.5281/zenodo.5070434 (2021).
Georgarakis, A.-M., Xiloyannis, M., Wolf, P. & Riener, R. The Myoshirt code repository. Zenodo https://doi.org/10.5281/zenodo.5070434 (2021).
We thank J. Song and D. Hollinger for their valuable contributions during the development and evaluation of the Myoshirt, and furthermore the students and research staff at the Sensory–Motor Systems Lab for their contributions and helpful feedback: F. Haufe, S. Brendle, F. Teuscher, D. Ozan and M. Macuglia. Finally, we would like to thank our participants for their time and insightful feedback. This work was supported by the Swiss National Center of Competence in Research (NCCR) Robotics, Swiss National Science Foundation 51_NF_40_185543, received by R.R.
The authors declare no competing interests.
Peer review information
Nature Machine Intelligence thanks Leonardo Cappello, Nicola Vitiello, Alessandra Pedrocchi and Lorenzo Masia for their contribution to the peer review of this work.
Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
About this article
Cite this article
Georgarakis, AM., Xiloyannis, M., Wolf, P. et al. A textile exomuscle that assists the shoulder during functional movements for everyday life. Nat Mach Intell 4, 574–582 (2022). https://doi.org/10.1038/s42256-022-00495-3