Takanori Uchiyama

Ryusei Uchida2
Ryoko Kato2
Mitsuyoshi Murayama2
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Spinal recurrent inhibition linking skeleto- motoneurons (alpha-MNs) via Renshaw cells (RCs) has been variously proposed to increase or decrease tendencies toward synchronous discharges between alpha-MNs. This controversy is not easy to settle experimentally in animal or human paradigms because RCs receive, in addition to excitatory input from alpha-MNs,(More)
The physiological function of spinal recurrent inhibition is still a matter of debate because of the experimental difficulty or impossibility of observing recurrent inhibition at work in normally behaving animals. The purpose of this study was to investigate, by computer simulation, the role of recurrent inhibition in shaping the input-output (I/O)(More)
A mechanomyogram (MMG) from single motor units of the anconeus muscle in voluntary isometric contraction was recorded from seven subjects using a spike-triggered averaging technique. The MMG system, in which the input was an ideal impulse and the output was the MMG detected with an acceleration sensor, was identified as the fifth-order model by the(More)
Recurrent inhibition in the mammalian spinal cord is complex, and its functions are not yet well understood. Skeletomotoneurons (alpha-MNs) excite, via recurrent axon collaterals, inhibitory Renshaw cells (RCs), which in turn inhibit alpha-MNs and other neurons. The anatomical and functional structure of the recurrent inhibitory network is nonhomogeneous,(More)
The aims of this study were to develop a method to extract the evoked mechanomyogram (MMG) during cycling exercise and to clarify muscle stiffness at various cadences, workloads, and power. Ten young healthy male participants were instructed to pedal a cycle ergometer at cadences of 40 and 60 rpm. The loads were 4.9, 9.8, 14.7, and 19.6 N, respectively. One(More)
The purpose of this study is to verify the applicability of a sixth-order model to the mechanomyogram (MMG) system of the parallel-fibered muscle, which was identified from the MMG of the pennation muscle. The median nerve was stimulated, and an MMG and torque of the abductor pollicis brevis muscle were measured. The MMGs were detected with either a(More)
This study aimed to investigate the relationship between muscle hardness and muscle tension in terms of length–tension relationship. A frog gastrocnemius muscle sample was horizontally mounted on the base plate inside a chamber and was stretched from 100 to 150% of the pre-length, in 5% increments. After each step of muscle lengthening, electrical field(More)
In the quantitative assessment of a system, a description of the low-order transfer function model is important. The objective of this study was to identify the system of a mechanomyogram (MMG) with SubSpace-based State Space model IDentification (4SID). The input data consisted of the electrical stimulation of the common peroneal nerve, which made the(More)
The objective of this study is to propose a new indices to evaluate spasticity in the ankle joint of hemiplegic patients. Each subject sat on a bed with one foot supported with a jig, which was used to measure the response of the ankle joint angle. The subject was instructed to relax and not to generate voluntary force. A step-like load was applied to(More)
This is a proposal for a new technique for evaluating spasticity in the upper limbs of hemiplegic patients. Each subject sat on a chair or stood up, and his or her forearm was extended or flexed by a physician. The subject was instructed to relax. The elbow joint angle, torque, and electromyograms (EMGs) of the biceps brachii, triceps brachii, and(More)