This paper examines the physiological mechanisms responsible for differences in the amplitude of force fluctuations between young and old adults. Because muscle force is a consequence of motor unit activity, the potential mechanisms include both motor unit properties and the behavior of motor unit populations. The force fluctuations, however, depend not only on the age of the individual but als...

Differences between motor units in hindlimb locomotor muscles of male and female Wistar rats were studied. The contractile and action potential properties of various types of motor units as well as proportions of these units in the medial gastrocnemius muscle were analyzed. Experiments were based on functional isolation and electrical stimulation of axons of single motor units. Composition of m...

Catalytic naphtha reforming is one of the most important processes in which, low quality naphtha is converted into high octane motor gasoline. In this study, a mathematical model was developed and was used for investigation the effect of temperature, pressure, hydrogen to hydrocarbon ratio on the octane number, the yield of product and the undesirable phenomena of coke deposition in a semiregen...

The amplitude of the surface EMG does not reach the level achieved during a maximal voluntary contraction force at the end of a sustained, submaximal contraction, despite near-maximal levels of voluntary effort. The depression of EMG amplitude may be explained by several neural and muscular adjustments during fatiguing contractions, including decreased net neural drive to the muscle, changes in...

The capabilities of the different types of motor units are reviewed, and their properties in a variety of muscles are discussed. Because the tension-generating capacities of motor units are so different, the order in which they are recruited will have a strong influence on the way force output of the whole muscle is graded. Activation of motor units in a random order produces a roughly linear f...

Compound muscle action potential (CMAP) and motor unit number estimation (MUNE) are electrophysiological techniques that can be used to monitor the functional status of a motor unit pool in vivo. These measures can provide insight into the normal development and degeneration of the neuromuscular system. These measures have clear translational potential because they are routinely applied in diag...