The goal of this work is to present methodology to first evaluate the performance of an in vivo spine system and then to synthesize optimal neuromuscular control for rehabilitation interventions. This is achieved (1) by determining control system parameters such as static feedback gains and delays from experimental data, (2) by synthesizing the optimal feedback gains to attenuate the effect of disturbances to the system using modern control theory, and (3) by evaluating the robustness of the optimized closed-loop system. We also apply these methods to a postural control task, with two different control strategies, and evaluate the robustness of the spine system with respect to longer latencies found in the low back pain population. This framework could be used for rehabilitation design. To this end, we discuss several future research needs necessary to implement our framework in practice.
1.
Crisco
, J.
, and Panjabi
, M.
, 1992, “Euler Stability of the Human Ligamentous Lumbar Spine: Part I. Theory
,” Clin. Biomech. (Bristol, Avon)
0268-0033, 7
, pp. 19
–26
.2.
Reeves
, N. P.
, Narendra
, K.
, and Cholewicki
, J.
, 2007, “Spine Stability: The Six Blind Men and the Elephant
,” Clin. Biomech. (Bristol, Avon)
0268-0033, 22
(3
), pp. 266
–274
.3.
Marras
, W. S.
, Davis
, K. G.
, and Maronitis
, A. B.
, 2001, “A Non-MVC EMG Normalization Technique for the Trunk Musculature: Part 2. Validation and Use to Predict Spinal Loads
,” Journal of Electromyography and Kinesiology
1050-6411, 11
(1
), pp. 11
–18
.4.
Larivière
, C.
, Gagnon
, D.
, and Loisel
, P.
, 2000, “The Comparison of Trunk Muscles EMG Activation Between Subjects With and Without Chronic Low Back Pain During Flexionextension and Lateral Bending Tasks
,” J. Electromyogr Kinesiol
1050-6411, 10
(2
), pp. 79
–91
.5.
van Dieën
, J.
, Cholewicki
, J.
, and Radebold
, A.
, 2003, “Trunk Muscle Recruitment Patterns in Patients With Low Back Pain Enhance the Stability of the Lumbar Spine
,” Spine
0362-2436, 28
(8
), pp. 834
–841
.6.
Hodges
, P.
, Moseley
, G.
, Gabrielsson
, A.
, and Gandevia
, S.
, 2003, “Experimental Muscle Pain Changes Feedforward Postural Responses of the Trunk Muscles
,” Exp. Brain Res.
0014-4819, 151
(2
), pp. 262
–271
.7.
Reeves
, N.
, Everding
, V.
, Cholewicki
, J.
, and Morrisette
, D.
, 2006, “The Effects of Trunk Stiffness on Postural Control During Unstable Seated Balance
,” Exp. Brain Res.
0014-4819, 174
(4
), pp. 694
–700
.8.
Stein
, R.
, Hunter
, I.
, Lafontaine
, S.
, and Jones
, L.
, 1995, “Analysis of Short-Latency Reflexes in Human Elbow Flexor Muscles
,” J. Neurophysiol.
0022-3077, 73
(5
), pp. 1900
–1911
.9.
Magnusson
, M.
, Aleksiev
, A.
, Wilder
, D.
, Pope
, M.
, Spratt
, K.
, Lee
, S.
, Goel
, V.
, and Weinstein
, J.
, 1996, “Unexpected Load and Asymmetric Posture as Etiologic Factors in Low Back Pain
,” Eur. Spine J.
0940-6719, 5
, pp. 23
–35
.10.
Radebold
, A.
, Cholewicki
, J.
, Panjabi
, M.
, and Patel
, T.
, 2000, “Muscle Response Pattern to Sudden Trunk Loading in Healthy Individuals and in Patients With Chronic Low Back Pain
,” Spine
0362-2436, 25
(8
), pp. 947
–954
.11.
Reeves
, N.
, Cholewicki
, J.
, and Milner
, T.
, 2005, “Muscle Reflex Classification of Low-Back Pain
,” J. Electromyogr Kinesiol
1050-6411, 15
(1
), pp. 53
–60
.12.
Thomas
, J.
, France
, C.
, Sha
, D.
, Vander Wiele
, N.
, Moenter
, S.
, and Swank
, K.
, 2007, “The Effect of Chronic Low Back Pain on Trunk Muscle Activations in Target Reaching Movements With Various Loads
,” Spine
0362-2436, 32
(26
), pp. E801
–E808
.13.
Mientjes
, M. I.
, and Frank
, J. S.
, 1999, “Balance in Chronic Low Back Pain Patients Compared to Healthy People Under Various Conditions in Upright Standing
,” Clin. Biomech. (Bristol, Avon)
0268-0033, 14
(10
), pp. 710
–716
.14.
Luoto
, S.
, Aalto
, H.
, Taimela
, S.
, Hurri
, H.
, Pyykko
, I.
, and Alaranta
, H.
, 1998, “One-Footed and Externally Disturbed Two-Footed Postural Control in Patients With Chronic Low Back Pain and Healthy Control Subjects: A Controlled Study With Follow-Up
,” Spine
0362-2436, 23
(19
), pp. 2081
–2089
.15.
Radebold
, A.
, Cholewicki
, J.
, Polzhofer
, G.
, and Greene
, H.
, 2001, “Impaired Postural Control of the Lumbar Spine Is Associated With Delayed Muscle Response Times in Patients With Chronic Idiopathic Low Back Pain
,” Spine
0362-2436, 26
(7
), pp. 724
–730
.16.
Hodges
, P.
, van den Hoorn
, W.
, Dawson
, A.
, and Cholewicki
, J.
, 2009, “Changes in the Mechanical Properties of the Trunk in Low Back Pain May Be Associated With Recurrence
,” J. Biomech.
0021-9290, 42
(1
), pp. 61
–66
.17.
Zhou
, K.
, Doyle
, J.
, and Glover
, K.
, 1996, Robust and Optimal Control
, Prentice-Hall
, Upper Saddle River, NJ
.18.
Boyd
, S.
, 1994, Linear Matrix Inequalities in System and Control Theory
, Society for Industrial Mathematics & Applied Mathematics (SIAM)
.19.
Dullerud
, G.
, and Paganini
, F.
, 2000, A Course in Robust Control Theory: A Convex Approach
, Springer
, New York
.20.
Silfies
, S. P.
, Cholewicki
, J.
, Reeves
, N. P.
, and Greene
, H. S.
, 2007, “Lumbar Position Sense and the Risk of Low Back Injuries in College Athletes: A Prospective Cohort Study
,” BMC Musculoskelet. Disord.
, 8
(1
), pp. 129
.21.
Reeves
, N.
, Cholewicki
, J.
, Milner
, T.
, and Lee
, A.
, 2008, “Trunk Antagonist Coactivation Is Associated With Impaired Neuromuscular Performance
,” Exp. Brain Res.
0014-4819, 188
(3
), pp. 457
–463
.22.
van der Kooij
, H.
, van Asseldonk
, E.
, and van der Helm
, F.
, 2005, “Comparison of Different Methods to Identify and Quantify Balance Control
,” J. Neurosci. Methods
0165-0270, 145
(1–2
), pp. 175
–203
.23.
Cordo
, P.
, Inglis
, J.
, Verschueren
, S.
, Collins
, J.
, Merfeld
, D.
, Rosenblum
, S.
, Buckley
, S.
, and Moss
, F.
, 1996, “Noise in Human Muscle Spindles
,” Nature (London)
0028-0836, 383
(6603
), pp. 769
–770
.24.
Reeves
, N.
, Cholewicki
, J.
, and Narendra
, K.
, 2009, “Effects of Reflex Delays on Postural Control During Unstable Seated Balance
,” J. Biomech.
0021-9290, 42
(2
), pp. 164
–70
.25.
Prochazka
, A.
, Gillard
, D.
, and Bennett
, D.
, 1997, “Implications of Positive Feedback in the Control of Movement
,” J. Neurophysiol.
0022-3077, 77
(6
), pp. 3237
–3251
.26.
El Ghaoui
, L.
, and Balakrishnan
, V.
, 1994, “Synthesis of Fixed-Structure Controllers Via Numerical Optimization
,” Proceedings of the 33rd IEEE Conference on Decision and Control
, Vol. 3
.27.
Fukuda
, M.
, and Kojima
, M.
, 2001, “Branch-and-Cut Algorithms for the Bilinear Matrix Inequality Eigenvalue Problem
,” Comput. Optim. Appl.
0926-6003, 19
(1
), pp. 79
–105
.28.
Iwasaki
, T.
, 1999, “The Dual Iteration for Fixed-Order Control
,” IEEE Trans. Autom. Control
0018-9286, 44
(4
), pp. 783
–788
.29.
Kocvara
, M.
, and Stingl
, M.
, 2006, PENBMI User’s Guide (Version 2.1), PENOPT GbR, Germany.30.
Kami
, Y.
, and Nobuyama
, E.
, 2008, “A Gradient Method for the Static Output Feedback Mixed H2/H∞ Control
,” Proceedings of the 17th World Congress
, The International Federation of Automatic Control, Seoul, Korea, pp. 7838
–7842
.31.
Scherer
, C.
, Gahinet
, P.
, and Chilali
, M.
, 1997, “Multiobjective Output-Feedback Control Via LMI Optimization
,” IEEE Trans. Autom. Control
0018-9286, 42
(7
), pp. 896
–911
.32.
Fitzpatrick
, R.
, Burke
, D.
, and Gandevia
, S.
, 1996, “Loop Gain of Reflexes Controlling Human Standing Measured With the Use of Postural and Vestibular Disturbances
,” J. Neurophysiol.
0022-3077, 76
(6
), pp. 3994
–4008
.33.
Rack
, P.
, Ross
, H.
, and Thilmann
, A.
, 1984, “The Ankle Stretch Reflexes in Normal and Spastic Subjects: The Response to Sinusoidal Movement
,” Brain
0006-8950, 107
(2
), pp. 637
–654
.34.
Burdet
, E.
, Osu
, R.
, Franklin
, D.
, Milner
, T.
, and Kawato
, M.
, 2001, “The Central Nervous System Stabilizes Unstable Dynamics by Learning Optimal Impedance
,” Nature (London)
0028-0836, 414
(6862
), pp. 446
–449
.35.
Franklin
, D.
, Osu
, R.
, Burdet
, E.
, Kawato
, M.
, and Milner
, T.
, 2003, “Adaptation to Stable and Unstable Dynamics Achieved by Combined Impedance Control and Inverse Dynamics Model
,” J. Neurophysiol.
0022-3077, 90
(5
), pp. 3270
–3282
.Copyright © 2010
by American Society of Mechanical Engineers
You do not currently have access to this content.
