In order to assess the significance of the dynamics of neural control signals for the rise time of muscle moment, simulations of isometric and dynamic plantar flexion contractions were performed using electromyographic signals (EMG signals) of m. triceps surae as input. When excitation dynamics of the muscle model was optimized for an M-wave of the medial head of m. gastrocnemius (GM), the model was able to make reasonable predictions of the rise time of muscle moment during voluntary isometric plantar flexion contractions on the basis of voluntary GM EMG signals. The rise time of muscle moment in the model was for the greater part determined by the amplitude of the first EMG burst. For dynamic jumplike movements of the ankle joint, however, no relationship between rise time of muscle moment in the experiment and muscle moment predicted by the model on the basis of GM EMG signals was found. Since rise time of muscle moment varied over a small range for this movement, it cannot be completely excluded that stimulation dynamics plays a role in control of these simple single-joint movements. [S0148-0731(00)01104-3]

1.
van Zandwijk
,
J. P.
,
Bobbert
,
M. F.
,
Harlaar
,
J.
, and
Hof
,
A. L.
,
1998
, “
From Twitch to Tetanus for Human Muscle: Experimental Data and Model Predictions for Triceps Surae
,”
Biol. Cybern.
,
79
, pp.
121
130
.
2.
Hof
,
A. L.
, and
van Den Berg
,
Jw.
,
1981
, “
EMG to Force Processing I–IV
,”
J. Biomech.
,
14
, pp.
747
792
.
3.
van Ruijven
,
L. J.
, and
Weijs
,
W. A.
,
1990
, “
A New Model for Calculating Muscle Forces From Electromyograms
,”
Eur. J. Appl. Physiol.
,
61
, pp.
479
485
.
4.
Basmajian, J. V., 1978, Muscles Alive: Their Functions Revealed by Electromyography, Williams and Wilkins, Baltimore.
5.
Prochazka
,
A.
,
Gautier
,
M.
,
Wieler
,
M.
, and
Kenwell
,
Z.
,
1997
, “
The Bionic Glove: An Electrical Stimulator Garment That Provides Grasp and Hand Opening in Quadriplegia
,”
Arch. Phys. Med. Rehabil.
,
78
, pp.
608
614
.
6.
Simon
,
J.-N. M.
,
1962
, “
Dispositif de Contention des E´lectrodes de Stimulation Pour l’E´tude du Re´flex de Hoffman Chez l’Homme
,”
Electroencephalogr. Clin. Neurophysiol. Suppl.
,
22
,
174
176
.
7.
van Soest
,
A. J.
, and
Bobbert
,
M. F.
,
1993
, “
The Contribution of Muscle Properties in the Control of Explosive Movements
,”
Biol. Cybern.
,
69
, pp.
195
204
.
8.
van Zandwijk
,
J. P.
,
Bobbert
,
M. F.
,
Baan
,
G. C.
, and
Huijing
,
P. A.
,
1996
, “
From Twitch to Tetanus: Performance of Excitation Dynamics Optimized for a Twitch in Predicting Tetanic Muscle Forces
,”
Biol. Cybern.
,
75
, pp.
409
417
.
9.
van Zandwijk
,
J. P.
,
Baan
,
G. C.
,
Bobbert
,
M. F.
, and
Huijing
,
P. A.
,
1997
, “
Evaluation of a Self-Consistent Method for Calculating Muscle Parameters From a Set of Isokinetic Releases
,”
Biol. Cybern.
,
77
, pp.
277
282
.
10.
Hatze
,
H.
,
1977
, “
A Myocybernetic Control Model of Skeletal Muscle
,”
Biol. Cybern.
,
25
, pp.
103
119
.
11.
Hatze, H., 1981, “Myocybernetic Control Models of Skeletal Muscle,” University of South Africa report, Pretoria.
12.
Shampine, L. F., and Gordon, M. K., 1975, “Computer Solution of Ordinary Differential Equations: The Initial Value Problem,” W. H. Freeman, San Francisco.
13.
Hof
,
A. L.
,
Pronk
,
C. N. A.
, and
van Best
,
J. A.
,
1987
, “
Comparison Between EMG to Force Processing and Kinetic Analysis for the Calf Muscle Moment in Walking and Stepping
,”
J. Biomech.
,
20
, pp.
167
178
.
14.
Bobbert
,
M. F.
,
Huijing
,
P. A.
,
van Ingen Schenau
,
G. J.
,
1986
, “
A Model of the Human M. Triceps Surae Muscle–Tendon Complex Applied to Jumping
,”
J. Biomech.
,
19
, pp.
887
898
.
15.
Jacobs
,
R.
,
Bobbert
,
M. F.
, and
van Schenau Ingen
,
G. J.
,
1996
, “
Mechanical Output From Individual Leg Muscles During Explosive Leg Extensions: The Role of Biarticular Muscles
,”
J. Biomech.
,
29
, pp.
513
523
.
16.
Johnson
,
M. A.
,
Polgar
,
J.
,
Weightman
,
D.
, and
Appleton
,
D.
,
1973
, “
Data on the Distribution of Fibre Types in Thirty-Six Human Muscles, An Autopsy Study
,”
J. Neurol. Sci.
,
18
, pp.
111
129
.
17.
Bellemare
,
F.
,
Woods
,
J. J.
,
Johansson
,
R.
, and
Bigland-Richie
,
B.
,
1983
, “
Motor-Unit Discharge Rates in Maximal Voluntary Contractions of Three Human Muscles
,”
J. Neurophysiol.
,
50
, pp.
1380
1392
.
18.
Milner-Brown
,
H. S.
, and
Stein
,
R. B.
,
1975
, “
The Relation Between the Surface Electromyogram and Muscular Force
,”
J. Physiol. (Lond)
,
246
, pp.
549
569
.
19.
Fuglevand
,
A. J.
,
Winter
,
D. A.
, and
Patla
,
A. E.
,
1993
, “
Models of Recruitment and Rate Coding Organization in Motor-Unit Pools
,”
J. Neurophysiol.
,
70
, pp.
2470
2488
.
20.
Gottlieb
,
G. L.
,
Corcos
,
D. M.
, and
Agarwal
,
G. C.
,
1989
, “
Strategies for the Control of Single Mechanical Degree of Freedom Voluntary Movements
,”
Behav. Brain Sci.
,
12
, pp.
189
210
.
You do not currently have access to this content.