Yoshibumi Bunno

By Yoshibumi Bunno, Yuki Fukumoto, Todo Marina and Chieko Onigata

We investigated the influence of the imagined muscle contraction strengths on spinal motor neuron excitability in healthy volunteers. F‐wave was used for assessing spinal motor excitability. The F‐waves during motor imagery (MI) under 10, 30, 50, 70, and 100% maximal voluntary contractions (MVCs) were compared. Furthermore, we investigated changes of the F‐waves during motor imagery for 5 min. Motor imagery under 10, 30, 50, 70, and 100% maximal voluntary contractions can increase spinal motor neuron excitability. However, the imagined muscle contraction strengths were not involved in changes of spinal motor neuron excitability. Additionally, spinal motor neuron excitability after 5 min from onset of motor imagery returned to the rest level. Thus, in clinical use of motor imagery, slightly imagined muscle contraction strength is enough for facilitating spinal motor neuron excitability. Also, duration of motor imagery needs to be considered.

Part of the book: Neurological Physical Therapy

By Yuki Fukumoto and Yoshibumi Bunno

Purpose: This study aimed to examine the effects of motor imagery on the excitability of spinal motor neurons and accurate motion. Subjects and Methods: About 30 healthy volunteers were recruited. F-waves were recorded at rest, while touching a sensor and motor imagery conditions. Also, the pinch force was measured before and after motor imagery. Furthermore, the subjects mastered the 50% MVC pinch force with learning times of 10 s, 30 s, 1 min, and 2 min beforehand. Results: Spinal motor neuron excitability with motor imagery after motor learning for 10 s, 30 s, 1 min, and 2 min was significantly increased as compared to other conditions. Accurate motion in the pinch task after motor imagery was better maintained than in the pinch task before motor imagery with motor learning times of 30 s and 1 min. However, with learning times of 10s and 2 min, the subject?s ability to sustain accurate motion in the pinch task after motor imagery was significantly decreased as compared to that of the pinch task before motor imagery. Conclusion: Motor imagery increases spinal motor neuron excitability. To maximally improve accurate motion using motor imagery, it is important to practice and master motor learning beforehand

Part of the book: Neurological Physical Therapy

By Yoshibumi Bunno

We investigated the influence of the imagined muscle contraction strength on the spinal motor neural excitability and sympathetic nerve activity by using the F-wave and heart rate variability analysis. Motor imagery of isometric thenar muscle activity increased the spinal motor neuron excitability and sympathetic nerve activity. The imagined muscle contraction strength did not affect changes of the spinal motor neuron excitability and sympathetic nerve activity. Therefore, Motor imagery at slight imagined muscle contraction strength can facilitate the spinal motor neuron excitability without physical load. Motor imagery-based Brain-machine interface is widely used for neurorehabilitation. To achieve better outcomes in neurorehabilitation used Brain-machine interface, performing trained motor imagery would be required, and the F-wave may be exploited an index of motor imagery training effect.

Part of the book: Evolving BCI Therapy

By Yoshibumi Bunno

Immediate enrollment in physical therapy and facilitation of the spinal motor neuron excitability are very important. We previously suggested that the F-wave parameters were significantly increased during motor imagery. Thus, motor imagery is a beneficial method to facilitate the spinal motor neuron excitability for patients with various motor dysfunctions. We also indicated that the imagined muscle contraction strength may not affect the spinal motor neuron excitability. Additionally, kinesthetic imagery can more facilitate the spinal motor neuron excitability; however, longer duration of motor imagery may decrease the spinal motor neuron excitability. Thus, when applying motor imagery to physical therapy, slight imagined muscle contraction strength may be sufficient to facilitate the spinal motor neuron excitability, and the duration and strategy of imagery should be considered.

Part of the book: Physical Therapy Effectiveness

By Yoshibumi Bunno

The immediate enrollment in rehabilitation program and facilitation of the excitability of spinal motor neurons are very important for post-stroke patients. We previously suggested that persistence and the F/M amplitude ratio, indicator of the excitability of spinal motor neurons, were significantly increased during MI. Thus, MI has a greater effect on the excitability of spinal motor neurons. We also indicated that the imagined muscle contraction strength may not affect the excitability of spinal motor neurons. Further, kinesthetic imagery can more facilitate the excitability of spinal motor neurons. However, longer duration of MI may not affect the excitability of spinal motor neurons. Therefore, slight imagined muscle contraction strength may be sufficient to facilitate the excitability of spinal motor neurons, and duration and strategy of imagery should be considered in neurorehabilitation.

Part of the book: Somatosensory and Motor Research

By Yoshibumi Bunno, Chieko Onigata and Toshiaki Suzuki

Motor imagery allows patients with difficulty in voluntary movements to mentally practice a target motor task. Numerous neurophysiological studies have investigated the mechanisms underlying the benefits of motor imagery, but many aspects remain unclear. Since both central and spinal neural function need to be leveraged to improve various motor functions, we have investigated motor imagery and spinal neural functions. Our previous research demonstrated a facilitation effect of motor imagery on spinal neural function and an immediate effect on muscle strength. Specifically, a mild imagined muscle contraction strength may be sufficient to enhance the excitability of spinal motor neurons. In addition, kinesthetic imagery or combined action observation and motor imagery may substantially enhance the excitability of spinal motor neurons. Also, keeping a position of the upper or lower extremities close to the desired movements leads to greater enhancement of the excitability of spinal motor neurons during motor imagery.

Part of the book: Physical Therapy