Biomedical subjects

Shu Morioka

Publications and source records attributed to Shu Morioka.

4 recordsLinked to original sources

PubMed2006

The influence of size perception and internal modeling on the control process while lifting.

The present study sought to verify object size perception through internal modeling while lifting an object. Electromyography (EMG) activity of the upper limb muscles was recorded while 20 healthy females alternately lifted two containers of the same weight, but were unequal in size. When subjects lifted the small container, a significant increase was observed in the EMG activity. Most subjects determined that the small container was heavier than the large container, and predicted that the large container would be heavier than the small container due to size difference. The results may be explained by supporting that subjects predict object weight based on perception of size through internal modeling; however, predictions are cross-checked and modified through sensory feedback based on subjective weight.

Adult↗

PubMed2005

The effects of an attentional demand tasks on standing posture control.

The present study sought to determine if the postural sway of a subject required to grasp a tray (motor task) holding a cup filled with water and prevent spilling (mental task), would be reduced by consciously redirecting attention to maintain the tray in a horizontal position. We hypothesized the mental task would increase the stabilization of standing postural balance. Postural sway was measured in 17 normal subjects under the following conditions: 1) holding a 100 g weight in each hand (total 200 g; no mental task), 2) holding with both hands a tray on which 200 g was placed (tray-holding task), and 3) holding with both hands a tray on which a cup filled with water weighing 200 g was placed in the center (mental task). Postural sway was significantly reduced during the mental task versus other tasks. Standing posture balance was stabilized when a mental task was added. Thus, we concluded that higher brain functions such as attention and consciousness exerted a significant influence over the control of standing posture.

Adult↗

PubMed2004

Influence of perceptual learning on standing posture balance: repeated training for hardness discrimination of foot sole.

The current study investigated the influence of perceptual learning training for hardness discrimination of sponge rubber by the soles on postural sway. Subjects consisted of 30 healthy male volunteers. They were divided into two groups of 15 each at random: perceptual learning training group and a control group. For hardness discrimination training, rubber sponges 5, 10, and 20 mm thick were combined to change the thickness of rubber to 5, 10, 15, 20, and 25 mm. The hardness discrimination training was administered with eyes closed in the standing position for each day for 10 days. The center of pressure measured using a stabilometer was used as the indicator for postural sway. Postural sway was measured for 30 s with eyes open and closed before and after hardness discrimination training. Statistical analysis was performed for length, enveloped area, and rectangular area. Postural sway after training showed a significant decrease compared to sway before training in the perceptual learning training group. However, there was no change on postural sway in the control group. In conclusion, data indicate that the ability of the healthy subjects to regulate their standing posture improved with improvement of the perceptive ability of the soles.

Adult↗

PubMed2003

Effects of perceptual learning exercises on standing balance using a hardness discrimination task in hemiplegic patients following stroke: a randomized controlled pilot trial.

OBJECTIVE: To investigate the effect of perceptual learning exercises for hardness discrimination by the soles on standing balance in stroke patients with hemiplegia. SUBJECTS: Twenty-eight subjects were randomly assigned to an experimental or a control group and participated in a rehabilitation programme. INTERVENTION: The experimental group received perceptual learning exercises on hardness discrimination using three different levels of hardness of a rubber sponge for 10 days. MAIN MEASURES: Length, enveloped area and rectangular area of the parameter of postural sway were measured by a stabilometer on entry into the study and after 10 days. RESULTS: Twenty-six subjects completed the study. Data indicate that more parameters indicating postural sway were significantly decreased in the experimental group than in the control group. Also, there was a significant difference between the groups in change scores (pre-exercise minus post-exercise) of length and enveloped area. CONCLUSION: The plantar perception exercise used as a method in this study is considered to be effective as a supplemental exercise for standing balance. The possibility of clinical application using the hardness discrimination task with rubber as a balance exercise is therefore suggested.

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