Adaptive Ankle Resistance from a Wearable Robotic Device to Improve Muscle Recruitment in Cerebral Palsy
- 22 Downloads
Individuals with cerebral palsy can have weak and poorly coordinated ankle plantar flexor muscles that contribute to inefficient walking patterns. Previous studies attempting to improve plantar flexor function have had inconsistent effects on mobility, likely due to a lack of task-specificity. The goal of this study was to develop, validate, and test the feasibility and neuromuscular response of a novel wearable adaptive resistance platform to increase activity of the plantar flexors during the propulsive phase of gait. We recruited eight individuals with spastic cerebral palsy to walk with adaptive plantar flexor resistance provided from an untethered exoskeleton. The resistance system and protocol was safe and feasible for all of our participants. Controller validation demonstrated our ability to provide resistance that proportionally- and instantaneously-adapted to the biological ankle moment (R = 0.92 ± 0.04). Following acclimation to resistance (0.16 ± 0.02 Nm/kg), more-affected limbs exhibited a 45 ± 35% increase in plantar flexor activity (p = 0.02), a 26 ± 24% decrease in dorsiflexor activity (p < 0.05), and a 46 ± 25% decrease in co-contraction (tibialis anterior and soleus) (p = 0.02) during the stance phase. This adaptive resistance system warrants further investigation for use in a longitudinal intervention study.
KeywordsGait Task-specificity Co-contraction Training Soleus Untethered
Graphical user interface
Gross Motor Function Classification System
Maximum voluntary contraction
The authors would like to thank Nushka Remec, P.T., Emily Frank, R.N., Elizabeth Orum, and Jennifer Lawson for their assistance with data collection and processing. Research reported in this publication was supported in part by the Eunice Kennedy Shriver National Institute Of Child Health & Human Development of the National Institutes of Health under Award Number R03HD094583. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. This work was also supported in part by The University of Arizona College of Medicine – Phoenix MD/PhD Program.
Conflicts of interest
ZFL is a named inventor on a pending utility patent application that describes the exoskeleton utilized in the study. ZFL is a co-founder of a company seeking to commercialize the device.
- 3.Bayón, C., S. Lerma, O. Ramírez, J. I. Serrano, M. D. Del Castillo, R. Raya, J. M. Belda-Lois, I. Martínez, and E. Rocon. Locomotor training through a novel robotic platform for gait rehabilitation in pediatric population: short report. J. Neuroeng. Rehabil. 13:98, 2016.PubMedPubMedCentralCrossRefGoogle Scholar
- 4.Borggraefe, I., J. S. Schaefer, M. Klaiber, E. Dabrowski, C. Ammann-Reiffer, B. Knecht, S. Berweck, F. Heinen, and A. Meyer-Heim. Robotic-assisted treadmill therapy improves walking and standing performance in children and adolescents with cerebral palsy. Eur. J. Paediatr. Neurol. 14:496–502, 2010.PubMedCrossRefPubMedCentralGoogle Scholar
- 6.Burdea, G. C., D. Cioi, A. Kale, W. E. Janes, S. A. Ross, and J. R. Engsberg. Robotics and gaming to improve ankle strength, motor control, and function in children with cerebral palsy: a case study series. IEEE Trans. Neural Syst. Rehabil. Eng. 21:165–173, 2013.PubMedCrossRefPubMedCentralGoogle Scholar
- 17.Gage, J. R., M. H. Schwartz, S. E. Koop, and T. F. Novacheck. The Identification and Treatment of Gait Problems in Cerebral Palsy. London: Mac Keith Press, 2009.Google Scholar
- 29.Meyer-Heim, A., C. Ammann-Reiffer, A. Schmartz, J. Schafer, F. H. Sennhauser, F. Heinen, B. Knecht, E. Dabrowski, and I. Borggraefe. Improvement of walking abilities after robotic-assisted locomotion training in children with cerebral palsy. Arch. Dis. Child. 94:615–620, 2009.PubMedCrossRefPubMedCentralGoogle Scholar
- 36.Schmidt, R. A., and T. D. Lee. Motor Control and Learning: A Behavioral Emphasis. Champaign: Human Kinetics, 2011.Google Scholar
- 37.Scholtes, V. A., J. G. Becher, A. Comuth, H. Dekkers, L. Van Dijk, and A. J. Dallmeijer. Effectiveness of functional progressive resistance exercise strength training on muscle strength and mobility in children with cerebral palsy: a randomized controlled trial. Dev. Med. Child Neurol. 52:e107–e113, 2010.PubMedCrossRefGoogle Scholar
- 38.Scholtes, V. A., J. G. Becher, Y. J. Janssen-Potten, H. Dekkers, L. Smallenbroek, and A. J. Dallmeijer. Effectiveness of functional progressive resistance exercise training on walking ability in children with cerebral palsy: a randomized controlled trial. Res. Dev. Disabil. 33:181–188, 2012.PubMedCrossRefGoogle Scholar
- 39.Schroeder, A. S., M. Homburg, B. Warken, H. Auffermann, I. Koerte, S. Berweck, K. Jahn, F. Heinen, and I. Borggraefe. Prospective controlled cohort study to evaluate changes of function, activity and participation in patients with bilateral spastic cerebral palsy after Robot-enhanced repetitive treadmill therapy. Eur. J. Paediatr. Neurol. 18:502–510, 2014.PubMedCrossRefGoogle Scholar
- 45.Winstein, C., R. Lewthwaite, S. R. Blanton, L. B. Wolf, and L. Wishart. Infusing motor learning research into neurorehabilitation practice: a historical perspective with case exemplar from the accelerated skill acquisition program. J. Neurol. Phys. Ther. 38:190–200, 2014.PubMedPubMedCentralCrossRefGoogle Scholar