A new method of estimating the distribution of muscle fiber conduction velocities.

A computer-assisted method of estimating the distribution of muscle fiber conduction velocities is described. An electrode array composed of 2 stimulating and 4 recording electrodes is used to record surface muscle action potentials (MAPs) in response to direct muscle stimulation. The velocity distribution and the single muscle fiber action potential (SFAP) are calculated from the recorded MAPs by an iterative method of estimation. The estimation is based on the assumption that the spatial orientation of each muscle fiber viewed from the recording electrodes is the same along the muscle fibers and a MAP is recorded as a linear summation of all SFAPs. The accuracy of this estimation is demonstrated using simulated MAPs. The method is also tested on MAPs containing simulated amplifier noise, stimulus artifact, and errors in distance between electrodes. Finally we applied this method to MAP recordings of the biceps brachii in 23 healthy subjects. The velocity distribution was successfully estimated in 20 cases. The average of the estimated distributions was smaller than that described by previous workers. The reasons for the difference are discussed.

[1]  R. Cantello,et al.  Conduction velocity along human muscle fibers in situ , 1983, Neurology.

[2]  Jun Kimura,et al.  Electrodiagnosis in Diseases of Nerve and Muscle: Principles and Practice , 1983 .

[3]  F BUCHTHAL,et al.  Innervation zone and propagation velocity in human muscle. , 1955, Acta physiologica Scandinavica.

[4]  P. Hilfiker,et al.  Normal and myopathic propagation of surface motor unit action potentials. , 1984, Electroencephalography and clinical neurophysiology.

[5]  L J Dorfman,et al.  Nerve fiber conduction-velocity distributions. I. Estimation based on the single-fiber and compound action potentials. , 1979, Electroencephalography and clinical neurophysiology.

[6]  K Hanayama.  Recovery of conduction velocity of muscle fiber action potential after strenuous isometric contraction. , 1994, The Japanese journal of physiology.

[7]  W. Engel,et al.  The histographic analysis of human muscle biopsies with regard to fiber types , 1969, Neurology.

[8]  E. Norman Lurch.  Fundamentals of electronics , 1971 .

[9]  J. Trontelj.  Muscle fiber conduction velocity changes with length , 1993, Muscle & nerve.

[10]  P. Rosenfalck.  Intra- and extracellular potential fields of active nerve and muscle fibres. A physico-mathematical analysis of different models. , 1969, Acta physiologica Scandinavica. Supplementum.

[11]  D. Dumitru,et al.  Far‐field potentials in muscle , 1991, Muscle & nerve.

[12]  G Küchler,et al.  External potassium and action potential propagation in rat fast and slow twitch muscles. , 1991, General physiology and biophysics.

[13]  I. L. Freeston,et al.  Modeling of an Active Nerve Fiber in a Finite Volume Conductor and Its Application to the Calculation of Surface Action Potentials , 1979, IEEE Transactions on Biomedical Engineering.

[14]  G Hirose,et al.  A new method for estimation of nerve conduction velocity distribution in the frequency domain. , 1986, Electroencephalography and clinical neurophysiology.

[15]  D. Perkel,et al.  Nerve fiber conduction-velocity distributions. II. Estimation based on two compound action potentials. , 1979, Electroencephalography and clinical neurophysiology.

[16]  Dimitrov Gv.  Changes in the extracellular potentials produced by unmyelinated nerve fibre resulting from alterations in the propagation velocity or the duration of the action potential. , 1987 .

[17]  Fritz Buchthal,et al.  Evoked action potentials and conduction velocity in human sensory nerves , 1966 .

[18]  Håkan Askmark,et al.  Topographical localization of motor endplates in cryosections of whole human muscles , 1984, Muscle & nerve.

[19]  C. Håkansson.  Conduction velocity and amplitude of the action potential as related to circumference in the isolated fibre of frog muscle. , 1956, Acta physiologica Scandinavica.