Static optimization approaches to estimating muscle tensions rely on the assumption that the muscle activity pattern is in some sense optimal. However, in the case of individuals with a neuromuscular impairment, this assumption is likely not to hold true. We present an approach to muscle tension estimation that does not rely on any optimality assumptions. First, the nature of the impairment is estimated by reformulating the relationship between the muscle tensions and the external forces produced in terms of the deviation from the expected activation in the unimpaired case. This formulation allows the information from several force production tasks to be treated as a single coupled system. In a second step, the identified impairments are used to obtain a novel cost function for the muscle tension estimation task. In a simulation study of the index finger, the proposed method resulted in muscle tension errors with a mean norm of 23.3 ± 26.8% (percentage of the true solution norm), compared to 52.6 ± 24.8% when solving the estimation task using a cost function consisting of the sum of squared muscle stresses. Performance was also examined as a function of the amount of error in the kinematic and muscle Jacobians and found to remain superior to the performance of the squared muscle stress cost function throughout the range examined.

References

References
1.
Fraysse
,
F.
,
Dumas
,
R.
,
Cheze
,
L.
, and
Wang
,
X.
, 2009, “
Comparison of Global and Joint-To-Joint Methods for Estimating the Hip Joint Load and the Muscle Forces During Walking
,”
J. Biomech.
,
42
(
14
), pp.
2357
2362
.
2.
Lin
,
Y. C.
,
Walter
,
J. P.
,
Banks
,
S. A.
,
Pandy
,
M. G.
, and
Fregly
,
B. J.
, 2010, “
Simultaneous Prediction of Muscle and Contact Forces in the Knee During Gait
,”
J. Biomech.
,
43
(
5
), pp.
945
952
.
3.
Nussbaum
,
M. A.
, and
Chaffin
,
D. B.
, 1997, “
Pattern Classification Reveals Intersubject Group Differences in Lumbar Muscle Recruitment During Static Loading
,”
Clin. Biomech.
,
12
(
2
), pp.
97
106
.
4.
Brown
,
S. H.
, and
Potvin
,
J. R.
, 2005, “
Constraining Spine Stability Levels in an Optimization Model Leads to the Prediction of Trunk Muscle Cocontraction and Improved Spine Compression Force Estimates
,”
J. Biomech.
,
38
(
4
), pp.
745
754
.
5.
Hughes
,
R. E.
,
Rock
,
M. G.
, and
An
,
K. N.
, 1999, “
Identification of Optimal Strategies for Increasing Whole Arm Strength Using Karush-Kuhn-Tucker Multipliers
,”
Clin. Biomech.
,
14
(
9
), pp.
628
634
.
6.
van Drongelen
,
S.
,
van der Woude
,
L. H.
,
Janssen
,
T. W.
,
Angenot
,
E. L.
,
Chadwick
,
E. K.
, and
Veeger
,
D. H.
, 2005, “
Glenohumeral Contact Forces and Muscle Forces Evaluated in Wheelchair-Related Activities of Daily Living in Able-Bodied Subjects Versus Subjects With Paraplegia And Tetraplegia
,”
Arch. Phys. Med. Rehabil.
,
86
(
7
), pp.
1434
1440
.
7.
Brook
,
N.
,
Mizrahi
,
J.
,
Shoham
,
M.
, and
Dayan
,
J.
, 1995, “
A Biomechanical Model of Index Finger Dynamics
,”
Med. Eng. Phys.
,
17
(
1
), pp.
54
63
.
8.
Vigouroux
,
L.
,
Quaine
,
F.
,
Labarre-Vila
,
A.
,
Amarantini
,
D.
, and
Moutet
,
F.
, 2007, “
Using EMG Data to Constrain Optimization Procedure Improves Finger Tendon Tension Estimations During Static Fingertip Force Production
,”
J. Biomech.
,
40
(
13
), pp.
2846
2856
.
9.
Erdemir
,
A.
,
McLean
,
S.
,
Herzog
,
W.
, and
van den Bogert
,
A. J.
, 2007, “
Model-Based Estimation of Muscle Forces Exerted During Movements
,”
Clin. Biomech.
,
22
(
2
), pp.
131
154
.
10.
Bottasso
,
C. L.
,
Prilutsky
,
B. I.
,
Croce
,
A.
,
Imberti
,
E.
, and
Sartirana
,
S.
, 2006, “
A Numerical Procedure for Inferring From Experimental Data the Optimization Cost Functions Using a Multibody Model of the Neuro-Musculoskeletal System
,”
Multibody Syst. Dyn.
,
16
, pp.
123
154
.
11.
Terekhov
,
A. V.
,
Pesin
,
Y. B.
,
Niu
,
X.
,
Latash
,
M. L.
, and
Zatsiorsky
,
V. M.
, 2010, “
An Analytical Approach to the Problem of Inverse Optimization With Additive Objective Functions: An Application To Human Prehension
,”
J. Math. Biol.
,
61
(
3
), pp.
423
453
.
12.
Maier
,
M. A.
, and
Hepp-Reymond
,
M. C.
, 1995, “
EMG Activation Patterns During Force Production in Precision Grip. I. Contribution of 15 Finger Muscles to Isometric Force
,”
Exp. Brain Res.
,
103
(
1
), pp.
108
122
.
13.
Valero-Cuevas
,
F. J.
,
Zajac
,
F. E.
, and
Burgar
,
C. G.
, 1998, “
Large Index-Fingertip Forces are Produced by Subject-Independent Patterns of Muscle Excitation
,”
J. Biomech.
,
31
(
8
), pp.
693
703
.
14.
Holzbaur
,
K. R.
,
Murray
,
W. M.
, and
Delp
,
S. L.
, 2005, “
A Model of the Upper Extremity for Simulating Musculoskeletal Surgery and Analyzing Neuromuscular Control
,”
Ann. Biomed. Eng.
,
33
(
6
), pp.
829
840
.
15.
Jacobson
,
M. D.
,
Raab
,
R.
,
Fazeli
,
B. M.
,
Abrams
,
R. A.
,
Botte
,
M. J.
, and
Lieber
,
R. L.
, 1992, “
Architectural Design of the Human Intrinsic Hand Muscles
,”
J. Hand Surg. [Am]
,
17
(
5
), pp.
804
809
.
16.
Lin
,
H. T.
,
Su
,
F. C.
,
Wu
,
H. W.
, and
An
,
K. N.
, 2004, “
Muscle Forces Analysis in the Shoulder Mechanism During Wheelchair Propulsion
,”
Proc. Inst. Mech. Eng.
, Part H: J. Eng. Med.,
218
(
4
), pp.
213
221
.
17.
Qiu
,
D.
,
Fischer
,
H. C.
, and
Kamper
,
D. G.
, 2009, “
Muscle Activation Patterns During Force Generation of the Index Finger
,”
Proceedings of the Annual Intlernational Conference IEEE Engineering in Medicine and Biology Society
.
18.
Tubiana
,
R.
,
Thomine
,
J.-M.
, and
Mackin
,
E.
, 1996,
Examination of the Hand and Wrist
,
Martin Dunitz
,
London
.
19.
Lang
,
C. E.
, and
Schieber
,
M. H.
, 2004, “
Reduced Muscle Selectivity During Individuated Finger Movements in Humans After Damage to the Motor Cortex or Corticospinal Tract
,”
J. Neurophysiol.
,
91
(
4
), pp.
1722
1733
.
20.
Cruz
,
E. G.
,
Waldinger
,
H. C.
, and
Kamper
,
D. G.
, 2005, “
Kinetic and Kinematic Workspaces of the Index Finger Following Stroke
,”
Brain
,
128
(Pt
5
), pp.
1112
1121
.
21.
Tedroff
,
K.
,
Knutson
,
L. M.
, and
Soderberg
,
G. L.
, 2008, “
Co-Activity During Maximum Voluntary Contraction: A Study of Four Lower-Extremity Muscles in Children With and Without Cerebral Palsy
,”
Dev. Med. Child Neurol.
,
50
(
5
), pp.
377
381
.
22.
Seo
,
N. J.
,
Rymer
,
W. Z.
, and
Kamper
,
D. G.
, 2010. “
Altered Digit Force Direction During Pinch Grip Following Stroke
,”
Exp. Brain Res.
,
202
(
4
), pp.
891
901
.
23.
Young
,
S. J.
,
van Doornik
,
J.
, and
Sanger
,
T. D.
, 2010, “
Visual Feedback Reduces Co-Contraction in Children With Dystonia
,”
J. Child Neurol.
,
26
(
1
), pp.
37
43
.
24.
Ueda
,
J.
,
Ming
,
D.
,
Krishnamoorthy
,
V.
,
Shinohara
,
M.
, and
Ogasawara
,
T.
, 2010, “
Individual Muscle Control Using an Exoskeleton Robot for Muscle Function Testing
,”
IEEE Trans. Neural Syst. Rehabil. Eng.
,
18
, pp.
339
350
.
25.
Delp
,
S. L.
,
Anderson
,
F. C.
,
Arnold
,
A. S.
,
Loan
,
P.
,
Habib
,
A.
,
John
,
C. T.
,
Guendelman
,
E.
, and
Thelen
,
D. G.
, 2007, “
Opensim: Open-Source Software to Create and Analyze Dynamic Simulations of Movement
,”
IEEE Trans. Biomed. Eng.
,
54
(
11
), pp.
1940
1950
.
26.
An
,
K. N.
,
Ueba
,
Y.
,
Chao
,
E. Y.
,
Cooney
,
W. P.
, and
Linscheid
,
R. L.
, 1983, “
Tendon Excursion and Moment Arm of Index Finger Muscles
,”
J. Biomech.
,
16
(
6
), pp.
419
425
.
You do not currently have access to this content.