Failure of neuromuscular propagation during human maximal voluntary contraction

1988 ◽  
Vol 64 (3) ◽  
pp. 1084-1093 ◽  
Author(s):  
F. Bellemare ◽  
N. Garzaniti
Keyword(s):  
Ulnar Nerve ◽  
Nerve Stimulation ◽  
Wave Amplitude ◽  
Electrical Response ◽  
Muscle Metabolism ◽  
Normal Subjects ◽  
Voluntary Contraction ◽  
Adductor Pollicis ◽  
M Wave ◽  
Stimulation Of

The mechanism for fatigue of the adductor pollicis was studied in normal subjects during maximal voluntary contractions (MVC) sustained for 90-100 s, by comparing the force and electrical response of this muscle to voluntary motor drive with that obtainable with artificial stimulation of the ulnar nerve. The adequacy of nerve stimulation was checked by recording simultaneously the electrical response of a nonfatiguing muscle, the abductor of the small finger. The decrease in force and in the natural electrical activity with fatigue was accompanied by a parallel decrease in the amplitude of synchronous muscle action potentials (M waves) evoked by artificial stimulation of the ulnar nerve at different frequencies. The decline in M-wave amplitude in the adductor pollicis was not due to a submaximal nerve stimulation, since the amplitudes recorded simultaneously from the nonfatiguing abductor digiti minimi remained unchanged. The force and the electrical responses from the adductor pollicis recovered in parallel with a half time of approximately 1 min. These results suggest that the loss of force of the adductor pollicis with fatigue and its subsequent recovery are largely determined by the extent of neuromuscular propagation failure. The slow recovery of the M-wave amplitude during repetitive stimulation suggests that it may be related to some aspect of muscle metabolism.

scholarly journals A Measure of Peripheral Nerve Stimulation Efficacy Applicable to H-Reflex Studies

1996 ◽  
Vol 23 (4) ◽  
pp. 264-270 ◽  
Author(s):  
G.I. Boorman ◽  
J.A. Hoffer ◽  
K. Kallesoe ◽  
D. Viberg ◽  
C. Mah
Keyword(s):  
Ulnar Nerve ◽  
Soleus Muscle ◽  
Nerve Stimulation ◽  
Wave Amplitude ◽  
H Reflex ◽  
General Validity ◽  
Current Output ◽  
M Wave ◽  
Group I ◽  
Muscle Nerve

AbstractBackground: When H-reflexes are recorded during movement in human subjects, the stimulator current output is not a good indicator of sensory stimulation efficacy because of unavoidable nerve movement relative to the stimulus electrodes. Therefore, the M-wave amplitude has been used by researchers as an indicator of the efficacy of the stimulus. In this study we have examined the general validity of the hypothesis that the M-wave amplitude is directly proportional to the group I sensory afferent volley evoked by the stimulus. Methods: A nerve recording cuff, stimulating electrodes, and EMG recording electrodes were implanted in cats. Nerve cuff recordings of centrally propagating volleys evoked by electrical stimuli were directly compared to M-waves produced by the same stimuli. Compound action potentials (CAPs) recorded in the sciatic nerve were compared with soleus M-waves during either tibial nerve or soleus muscle nerve stimulation. CAPs in the ulnar nerve were correlated with flexor carpi ulnaris M-waves during ulnar nerve stimulation. Results and Conclusions: Our findings indicate that for mixed nerve stimulation (e.g., tibial or ulnar nerve) the M-wave can be a reliable indicator of the centrally propagating sensory volley. Due to the high correlation between CAP and M-wave amplitude in these nerves, a small number of M-waves can give a good estimate of the size of the group I sensory volley. On the other hand, when nerves with only partially overlaping fibre diameter populations are stimulated (e.g., the soleus muscle nerve), the M-wave is not well correlated with the group I sensory volley and thus may not be used as a measure of the size of the input volley for H-reflex studies.

Index finger position and force of the human first dorsal interosseus and its ulnar nerve antagonist

1994 ◽  
Vol 77 (2) ◽  
pp. 987-997 ◽  
Author(s):  
I. Zijdewind ◽  
D. Kernell
Keyword(s):  
Ulnar Nerve ◽  
Index Finger ◽  
Maximum Voluntary Contraction ◽  
Normal Subjects ◽  
Voluntary Contraction ◽  
Abduction Angle ◽  
Hand Position ◽  
First Dorsal Interosseus ◽  
Length Analysis ◽  
Neutral Angle

In normal subjects, maximum voluntary contraction (MVC) and electrical ulnar nerve stimulation (UNS; 30-Hz bursts of 0.33 s) were systematically compared with regard to the forces generated in different directions (abduction/adduction and flexion) and at different degrees of index finger abduction. With a “resting” hand position in which there was no index finger abduction, UNS produced about one-half of the abduction force elicited by an MVC (mean ratio 51%). Qualitatively, such a discrepancy would be expected, because UNS activates two index finger muscles with opposing actions in the abduction/adduction plane of torques: the first dorsal interosseus (FDI) and the first palmar interosseus (FPI). The abduction forces produced by MVC and UNS were very sensitive to index finger abduction angle: at a maximum degree of abduction, the UNS-generated force even reversed its direction of action to adduction (with FPI dominating) and the abduction MVC declined to 37% of that in the resting hand position. Inasmuch as these declines in MVC- and UNS-generated abduction force could not be explained by a change in moment arm, the main alternative seemed to be abduction-associated alterations in FDI fiber length (analysis by previously published biomechanical data). The FDI and FPI were further compared by application of a UNS-generated fatigue test (5-min burst stimulation), with the index finger kept at a "neutral" angle, i.e., the abduction angle at which, in the unfatigued state, the forces of the FDI and FPI were in balance (zero net UNS-generated abduction/adduction force).(ABSTRACT TRUNCATED AT 250 WORDS)

Fatigue of intermittent submaximal voluntary contractions: central and peripheral factors

1986 ◽  
Vol 61 (2) ◽  
pp. 421-429 ◽  
Author(s):  
B. Bigland-Ritchie ◽  
F. Furbush ◽  
J. J. Woods
Keyword(s):  
No Reduction ◽  
Rest Period ◽  
Central Fatigue ◽  
Voluntary Contraction ◽  
Adductor Pollicis ◽  
M Wave ◽  
Generating Capacity ◽  
Target Force ◽  
Voluntary Contractions ◽  
Muscle Contractile

Central and peripheral factors were studied in fatigue of submaximal intermittent isometric contractions of the human quadriceps and soleus muscles. Subjects made repeated 6 s, 50% maximal voluntary contractions (MVC) followed by 4 s rest until the limit of endurance (Tlim). Periodically, a fatigue test was performed. This included a brief MVC, either a single shock or 8 pulses at 50 Hz during a rest period and a shock superimposed on a target force voluntary contraction. At Tlim, the MVC force had declined by 50%, usually in parallel with the force from stimulation at 50 Hz. The twitches superimposed on the target forces declined more rapidly, disappearing entirely at Tlim. In similar experiments on adductor pollicis, no reduction of the evoked M wave was seen. The results suggest that, during fatigue of quadriceps and adductor pollicis induced by this protocol, no central fatigue was apparent, but some was seen in soleus. Thus the reduced force-generating capacity could result mainly or entirely from failure of the muscle contractile apparatus.

Fourier analysis of ‘m wave envelope’ on repetitive stimulation of the ulnar nerve

1983 ◽  
Vol 56 (3) ◽  
pp. S202
Author(s):  
Y. Yomura ◽  
H. Furuhashi ◽  
T. Ishigaki ◽  
A. Iida ◽  
K. Funabashi
Keyword(s):  
Fourier Analysis ◽  
Ulnar Nerve ◽  
Repetitive Stimulation ◽  
M Wave ◽  
Stimulation Of

Standardization of changes in M-wave area to repetitive stimulation of the ulnar nerve

1985 ◽  
Vol 61 (3) ◽  
pp. S85-S86
Author(s):  
I. Aiello ◽  
S. Traccis ◽  
G.F. Sau ◽  
G. Serra ◽  
D. De Grandis
Keyword(s):  
Ulnar Nerve ◽  
Repetitive Stimulation ◽  
M Wave ◽  
Stimulation Of

Adductor Pollicis Twitch Tension Assessed by Magnetic Stimulation of the Ulnar Nerve

2000 ◽  
Vol 162 (1) ◽  
pp. 240-245 ◽  
Author(s):  
MARY LOUISE HARRIS ◽  
YUAN M. LUO ◽  
ANNA C. WATSON ◽  
GERRARD F. RAFFERTY ◽  
MICHAEL I. POLKEY ◽  
...  
Keyword(s):  
Ulnar Nerve ◽  
Magnetic Stimulation ◽  
Adductor Pollicis ◽  
Stimulation Of

Cortical Characterization and Inter-Dipole Distance Between Unilateral Median Versus Ulnar Nerve Stimulation of Both Hands in MEG

2006 ◽  
Vol 19 (1-2) ◽  
pp. 29-42 ◽  
Author(s):  
Peter J. Theuvenet ◽  
Bob W. van Dijk ◽  
Maria J. Peters ◽  
Jan M. van Ree ◽  
Fernando L. Lopes da Silva ◽  
...  
Keyword(s):  
Ulnar Nerve ◽  
Nerve Stimulation ◽  
Stimulation Of

Inference of motor unit recruitment order in voluntary and electrically elicited contractions

1990 ◽  
Vol 68 (4) ◽  
pp. 1657-1667 ◽  
Author(s):  
M. Knaflitz ◽  
R. Merletti ◽  
C. J. De Luca
Keyword(s):  
Conduction Velocity ◽  
Motor Units ◽  
Voluntary Contraction ◽  
Motor Point ◽  
Spectral Parameters ◽  
M Wave ◽  
Recruitment Order ◽  
Stimulation Current ◽  
Voluntary Contractions ◽  
Stimulation Of

The relationship between surface myoelectric signal parameters and the level of voluntary or electrically elicited contractions was studied in 32 experiments on the tibialis anterior muscle of 22 healthy human subjects. Contractions were performed at 20 and 80% of the maximum voluntary contraction torque. Two levels of stimulation current were used, yielding, respectively, a maximum M wave and an M wave approximately 30% of the maximum. A four-bar electrode probe was used to detect single- and double-differential signals from which mean and median frequency of the power spectrum and average muscle fiber conduction velocity were estimated. Measurements obtained from voluntary contractions showed a positive correlation between contraction levels and both conduction velocity and spectral parameters. Conduction velocity increased by 21.2 +/- 10.9% when voluntary contraction level increased from 20 to 80% of the maximal value. Spectral parameters increased by similar amounts. Tetanic electrical stimulation was applied to a muscle motor point for 20 s via surface electrodes. Rectangular current pulses with 0.1-ms width and frequencies of 20, 25, 30, 35, and 40 Hz were used. Four types of behavior were observed with increasing stimulation level: 1) the two spectral parameters and conduction velocity both increased with stimulation in 15 experiments, 2) the two spectral parameters decreased and conduction velocity increased in 8 experiments, 3) the two spectral parameters and conduction velocity both decreased in 6 experiments, and 4) the two spectral parameters increased and conduction velocity decreased in 3 experiments. Conduction velocity increased with increasing stimulation current in 72% of the experiments, indicating a recruitment order similar to that of voluntary contractions, although it decreased in the other 28% of the cases, indicating a reverse order of recruitment. Contrary to what is observed in direct stimulation of nerves, motor units are not in general recruited in reverse order of size during electrical stimulation of a muscle motor point. This discrepancy may be the result of geometric factors or a lack of correlation between axonal branch diameter and the diameter of the parent motoneuron axon. Changes of conduction velocity and spectral parameters in opposite directions may be the result of the combined effect of the motor unit recruitment order and of the different tissue filtering function associated with the geometric location of the recruited motor units within the muscle.

Short-term immobilization has a minimal effect on the strength and fatigability of a human hand muscle

1995 ◽  
Vol 78 (3) ◽  
pp. 847-855 ◽  
Author(s):  
A. J. Fuglevand ◽  
M. Bilodeau ◽  
R. M. Enoka
Keyword(s):  
Wave Amplitude ◽  
Compound Muscle Action Potential ◽  
Maximum Voluntary Contraction ◽  
Voluntary Contraction ◽  
Emg Activity ◽  
Human Hand ◽  
Contraction Time ◽  
Endurance Time ◽  
M Wave ◽  
First Dorsal Interosseus

The purpose of this study was to determine the association between reduced fatigability typically observed in disused muscle and an improved resistance to the impairment of neuromuscular propagation. Endurance time of an isometric contraction sustained at 35% of maximum voluntary contraction (MVC) force and the fatigue-induced change in the evoked compound muscle action potential (M wave) were measured in the first dorsal interosseus muscle of human subjects before, during, and after 3 (n = 9) or 5 wk (n = 2) of immobilization. The immobilization procedure caused a substantial decline in the chronic electromyographic (EMG) activity (to 4% of control value) of the first dorsal interosseus muscle. Endurance time was found to be significantly correlated to the maintenance of M-wave amplitude during the fatigue task. However, neither of these variables was significantly affected by immobilization. Also, immobilization had no significant effect on the prefatigue values of MVC force and EMG or twitch contraction time or on the postfatigue changes in MVC force and EMG, M wave duration, twitch amplitude, and contraction time. In the unfatigued muscle, immobilization did cause an increase in twitch force (153%) and a decrease in M-wave amplitude (67%). It appears, therefore, that a healthy first dorsal interosseus muscle is generally resistant to adaptation when its use has been reduced for 3–5 wk by immobilization.

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