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European Journal of Applied Physiology

, Volume 114, Issue 11, pp 2341–2351 | Cite as

Enhancing performance during inclined loaded walking with a powered ankle–foot exoskeleton

  • Samuel Galle
  • Philippe Malcolm
  • Wim Derave
  • Dirk De Clercq
Original Article

Abstract

Purpose

A simple ankle–foot exoskeleton that assists plantarflexion during push-off can reduce the metabolic power during walking. This suggests that walking performance during a maximal incremental exercise could be improved with an exoskeleton if the exoskeleton is still efficient during maximal exercise intensities. Therefore, we quantified the walking performance during a maximal incremental exercise test with a powered and unpowered exoskeleton: uphill walking with progressively higher weights.

Methods

Nine female subjects performed two incremental exercise tests with an exoskeleton: 1 day with (powered condition) and another day without (unpowered condition) plantarflexion assistance. Subjects walked on an inclined treadmill (15 %) at 5 km h−1 and 5 % of body weight was added every 3 min until exhaustion.

Results

At volitional termination no significant differences were found between the powered and unpowered condition for blood lactate concentration (respectively, 7.93 ± 2.49; 8.14 ± 2.24 mmol L−1), heart rate (respectively, 190.00 ± 6.50; 191.78 ± 6.50 bpm), Borg score (respectively, 18.57 ± 0.79; 18.93 ± 0.73) and \(\dot{V}{\rm O}_{2}\) peak (respectively, 40.55 ± 2.78; 40.55 ± 3.05 ml min−1 kg−1). Thus, subjects were able to reach the same (near) maximal effort in both conditions. However, subjects continued the exercise test longer in the powered condition and carried 7.07 ± 3.34 kg more weight because of the assistance of the exoskeleton.

Conclusion

Our results show that plantarflexion assistance during push-off can increase walking performance during a maximal exercise test as subjects were able to carry more weight. This emphasizes the importance of acting on the ankle joint in assistive devices and the potential of simple ankle–foot exoskeletons for reducing metabolic power and increasing weight carrying capability, even during maximal intensities.

Keywords

Ankle–foot exoskeleton Locomotion Uphill walking Loaded walking Performance Exercise test Maximal exercise Exhaustion 

Notes

Acknowledgments

This research was supported by BOF10/DOC/288. The authors wish to thank Ing. Davy Spiessens for the technical support, Brecht Van Genabet and Hanneke Van Gucht for the support during data collection and Technische Orthopedie België for constructing the exoskeleton.

References

  1. Blaya JH, Herr H (2004) Adaptive control of a variable-impedance ankle–foot orthosis to assist drop-foot gait. IEEE Trans Neural Syst Rehab Eng 12:24–31CrossRefGoogle Scholar
  2. Borg G (1973) Perceived exertion: a note on “history” and methods. Med Sci Sports 5:90–93PubMedGoogle Scholar
  3. Brockway JM (1987) Derivation of formulae used to calculate energy-expenditure in man. Hum Nutr Clin Nutr 41C:463–471Google Scholar
  4. Cohen J (1977) Statistical power analysis for the behavioral sciences. Academic Press, New YorkGoogle Scholar
  5. Collins SH, Jackson RW (2013) A method for harnessing least-effort drives in robotic locomotion training (conference abstract). International conference on rehabilitation robotics, Seattle, WA, USA, Jun 24–26, 2013Google Scholar
  6. Collins SH, Kuo AD (2010) Recycling energy to restore impaired ankle function during human walking. PLoS One 5:e9307PubMedCrossRefPubMedCentralGoogle Scholar
  7. Daerden F, Lefeber D (2000) Pneumatic artificial muscles: actuators for robotics and automation. Eur J Mech Environ Eng 47:10–21Google Scholar
  8. Dollar AM, Herr H (2008) Lower extremity exoskeletons and active orthoses: challenges and state-of-the-art. IEEE Trans Robot Autom 24:144–158CrossRefGoogle Scholar
  9. Donelan JM, Li Q, Naing V, Hoffer JA, Weber DJ, Kuo AD (2008) Biomechanical energy harvesting: generating electricity during walking with minimal user effort. Science 319:807–810PubMedCrossRefGoogle Scholar
  10. Duerinck S, Swinnen E, Beyl P, Hagman F, Jonkers I, Vaes P, Van Roy P (2012) The added value of an actuated ankle-foot orthosis to restore normal gait function in patients with spinal cord injury: a systematic review. J Rehabil Med 44:299–309PubMedCrossRefGoogle Scholar
  11. Ferris DP, Sawicki GS, Daley MA (2007) A physiologist’s perspective on robotic exoskeletons for human locomotion. Int J Hum Robot 4:507–528CrossRefGoogle Scholar
  12. Franz JR, Kram R (2012) The effects of grade and speed on leg muscle activations during walking. Gait Posture 35:143–147PubMedCrossRefPubMedCentralGoogle Scholar
  13. Galle S, Malcolm P, Derave W, De Clercq D (2013a) Adaptation to walking with an exoskeleton that assists ankle extension. Gait Posture 38:495–499PubMedCrossRefGoogle Scholar
  14. Galle S, Malcolm P, Derave W, De Clercq D (2013b) Assisted plantarflexion influences muscular activity in all leg muscles during uphill walking (Conference abstract). XXIV Congress of the International Society of Biomechanics, Natal, Brazil, Aug 4–9, 2013Google Scholar
  15. Gregorczyk KN, Adams A (2012) Biomechanical and metabolic implication of wearing a powered exoskeleton to carry a backpack load (Conference abstract). 36th Annual Conference of the American Society of Biomechanics, Gainesville, FL, Aug 15–18, 2012 http://www.asbweb.org/conferences/2012/abstracts/52.pdf
  16. Gregorczyk KN, Obusek JP, Hasselquist L, Schiffman JM, Bensel CK, Gutekunst DJ, Frykman P (2006) The effects of a lower body exoskeleton load carriage assistive device on oxygen consumption and kinematics during walking with loads. Technical Report, 25th Army Sci Conf, Orlando, FL, Nov 27–30, 2006 http://www.dtic.mil/cgibin/GetTRDoc?Location=U2&doc=GetTRDoc.pdf&AD=ADA481701
  17. Gregorczyk KN, Hasselquist L, Schiffman JM, Bensel CK, Obusek JP, Gutekunst DJ (2010) Effects of a lower-body exoskeleton device on metabolic cost and gait biomechanics during load carriage. Ergonomics 53:1263–1275PubMedCrossRefGoogle Scholar
  18. Harman E, Hoon HK, Frykman P, Pandorf C (2000) The effects of backpack weight on the biomechanics of load carriage. Technical Report, U.S. Army Res Inst Environ Med, Natick, MA, May 3, 2000 http://oai.dtic.mil/oai/oai?verb=getRecord&metadataPrefix=html&identifier=ADA377886
  19. Herdy A, Uhlendorf D (2011) Reference values for cardiopulmonary exercise testing for sedentary and active men and women. Arq Bras Cardiol 96:54–59PubMedCrossRefGoogle Scholar
  20. Kazerooni H, Steger R (2006) The Berkeley lower extremity exoskeleton. J Dyn Syst Meas Control 128:14–25CrossRefGoogle Scholar
  21. Klimek AT, Klimek A (2007) The weighted walking test as an alternative method of assessing aerobic power. J Sports Sci 25:143–148PubMedCrossRefGoogle Scholar
  22. Knapik JJ, Harman EA, Steelman RA, Graham BS (2012) A systematic review of the effects of physical training on load carriage performance. J Strength Cond Res 26:585–597PubMedCrossRefGoogle Scholar
  23. Koch B, Schäper C, Ittermann T, Spielhagen T, Dörr M, Völzke H, Opitz CF, Ewert R, Gläser S (2009) Reference values for cardiopulmonary exercise testing in healthy volunteers: the SHIP study. Eur Respir J 33:389–397PubMedCrossRefGoogle Scholar
  24. Kramer PA (2010) The effect on energy expenditure of walking on gradients or carrying burdens. Am J Hum Biol 22:497–507PubMedCrossRefGoogle Scholar
  25. Lay AN, Hass CJ, Gregor RJ (2006) The effects of sloped surfaces on locomotion: a kinematic and kinetic analysis. J Biomech 39:1621–1628PubMedCrossRefGoogle Scholar
  26. Lay AN, Hass CJ, Nichols TR, Gregor RJ (2007) The effects of sloped surfaces on locomotion: an electromyographic analysis. J Biomech 40:1276–1285PubMedCrossRefGoogle Scholar
  27. Li Q, Naing V, Donelan JM (2009) Development of a biomechanical energy harvester. J Neuroeng Rehabil 6:22PubMedCrossRefPubMedCentralGoogle Scholar
  28. Malcolm P, Segers V, Van Caekenberghe I, De Clercq D (2009) Experimental study of the influence of the m. tibialis anterior on the walk-to-run transition by means of a powered ankle–foot exoskeleton. Gait Posture 29:6–10PubMedCrossRefGoogle Scholar
  29. Malcolm P, Derave W, Galle S, De Clercq D (2013) A simple exoskeleton that assists plantarflexion can reduce the metabolic cost of human walking. PLoS One 8:e56137PubMedCrossRefPubMedCentralGoogle Scholar
  30. Margaria (1976) Biomechanics and energetics of muscular exercise. Clarendon Press, OxfordGoogle Scholar
  31. McIntosh AS, Beatty KT, Dwan LN, Vickers DR (2006) Gait dynamics on an inclined walkway. J Biomech 39:2491–2502PubMedCrossRefGoogle Scholar
  32. Midgley AW, McNaughton LR, Polman R, Marchant D (2007) Criteria for determination of maximal oxygen uptake: a brief critique and recommendations for future research. Sports Med 37:1019–1028PubMedCrossRefGoogle Scholar
  33. Mooney LM, Rouse EJ, Herr HM (2014) Autonomous exoskeleton reduces metabolic cost of human walking during load carriage. J Neuroeng Rehabil 11:80PubMedCrossRefPubMedCentralGoogle Scholar
  34. Norris JA, Granata KP, Mitros MR, Byrne EM, Marsh AP (2007) Effect of augmented plantarflexion power on preferred walking speed and economy in young and older adults. Gait Posture 25:620–627PubMedCrossRefGoogle Scholar
  35. Pratt JE, Krupp BT, Morse CJ, Collins SH (2004) The RoboKnee: an exoskeleton for enhancing strength and endurance during walking (Conference Abstract). IEEE International Conference on Robotics Atomation, New Orleans, Apr 26–May 1, 2004: 2430–2435Google Scholar
  36. Sawicki GS, Ferris DP (2006) The effects of powered ankle-foot orthoses on joint kinematics and muscle activation during walking in individuals with incomplete spinal cord injury. J Neuroeng Rehabil 3:3PubMedCrossRefPubMedCentralGoogle Scholar
  37. Sawicki GS, Ferris DP (2008) Mechanics and energetics of level walking with powered ankle exoskeletons. J Exp Biol 211:1402–1413PubMedCrossRefGoogle Scholar
  38. Sawicki GS, Ferris DP (2009a) Mechanics and energetics of incline walking with robotic ankle exoskeletons. J Exp Biol 212:32–41PubMedCrossRefGoogle Scholar
  39. Sawicki GS, Ferris DP (2009b) Powered ankle exoskeletons reveal the metabolic cost of plantar flexor mechanical work during walking with longer steps at constant step frequency. J Exp Biol 212:21–31PubMedCrossRefGoogle Scholar
  40. Schiffman JM, Gregorczyk K, Hasselquist L, Bensel CK, Frykman P, Adams A, Obusek JP (2010) Can a lower body exoskeleton improve load-carriage march and post-march performance? Med Sci Sports Exerc 42:283CrossRefGoogle Scholar
  41. Unal R, Carloni R, Behrens SM, Hekman EE, Stramigioli S, Koopman HF (2012) Towards a fully passive transfemoral prosthesis for normal walking (Conference Abstract). 4th IEEE RAS & EMBS International Conference on Biomedical Robotics and Biomechatronics, Roma, Italy, Jun 24–27, 2012: 1949–1954Google Scholar
  42. Walsh CJ, Endo K, Herr H (2007) A quasi-passive leg exoskeleton for load-carrying augmentation. Int J HR 4:487–506Google Scholar
  43. Wehner M, Quinlivan B, Aubin PM, Martinez-Villalpando E, Baumann M, Stirling L, Holt K, Wood R, Walsh C (2013) A lightweight soft exosuit for gait assistance (Conference Abstract). IEEE International Conference on Robotics Atomation, Karlsruhe, Germany, May 6–10, 2013: 3362–3369Google Scholar
  44. Winter DA (1983) Energy generation and absorption at the ankle and knee during fast, natural, and slow cadences. Clin Orthop Relat Res 175:147–154PubMedGoogle Scholar
  45. Zoladz JA, Korzeniewski B (2001) Physiological background of the change point in \(\dot{V}{\rm O}_{2}\) and the slow component of oxygen uptake kinetics. J Physiol Pharmacol 52(2):167–184PubMedGoogle Scholar
  46. Zoss A, Kazerooni H, Chu A (2006) Biomechanical design of the Berkeley lower extremity exoskeleton (BLEEX). IEEE ASME Trans Mechatron 11:128–138CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  • Samuel Galle
    • 1
  • Philippe Malcolm
    • 1
  • Wim Derave
    • 1
  • Dirk De Clercq
    • 1
  1. 1.Department of Movement and Sport SciencesGhent UniversityGhentBelgium

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