Effects of attentional dispersion on sensory-motor processing of anticipatory postural control during unilateral arm abduction

Objective: We investigated effects of attentional dispersion on sensory-motor processing of anticipatory postural control during unilateral arm abduction. Methods: Thirteen adults performed arm abduction under two types of attentional dispersion conditions. A target stimulus was presented with 30% probability in two- or three-positions. By cue signal presentation, subjects either focused their attention on one position or divided attention for two or three positions and abducted right arm for target stimulus. Event-related potentials and onset time of postural muscles were measured. Results: P1-N1 and N2 amplitudes decreased with attentional dispersion in both conditions, but P3 did not change. With attentional dispersion to three-positions, N2 latency increased and start of late CNV was delayed, and also the onset time of gluteus medius was late in correlation to the late CNV changings, with no changings in two-positions. Conclusions: With attentional dispersion, brain activation decreased in the area related to the sensory processing and especially in the stimulus discrimination area. With increasing attentional dispersion, the delay in motor preparation or anticipatory attention to target stimuli was related to the delay in stimulus discrimination and onset time of postural muscle activation.Significance: Effects of attentional dispersion on sensory-motor processing of anticipatory postural control were experimentally demonstrated

予測的立位姿勢調節の学習能の発達

金沢大学教養部研究課題/領域番号:01780137, 研究期間(年度):1989出典：研究課題「予測的立位姿勢調節の学習能の発達」課題番号01780137（KAKEN：科学研究費助成事業データベース（国立情報学研究所）） （https://kaken.nii.ac.jp/ja/grant/KAKENHI-PROJECT-01780137/）を加工して作

平衡反応における制御様式の練習による変化

金沢大学教養部研究課題/領域番号:63780149, 研究期間(年度):1988出典：研究課題「平衡反応における制御様式の練習による変化」課題番号63780149（KAKEN：科学研究費助成事業データベース（国立情報学研究所）） （https://kaken.nii.ac.jp/ja/grant/KAKENHI-PROJECT-63780149/）を加工して作

体性感覚刺激強度・速度の違いによる姿勢応答特性及びその発達的変化

金沢大学医薬保健研究域医学系立位姿勢保持時の体性感覚情報は、感覚参照機構を介し姿勢制御に寄与すると考えられている。昨年度までに、成人被験者にて、中足骨骨頭部足底圧刺激および下腿三頭筋振動刺激の強度の違いによって、誘発される姿勢応答(前・後傾)が変化すること、およびその臨界値を明らかにできた。さらに、両刺激が低強度の場合にはマッチングされ姿勢が変化せず、いずれかの刺激が高強度の場合には、その刺激に対応するように姿勢が変化(後傾)することを明らかにした。今年度は、幼児期における下腿三頭筋振動刺激に対する姿勢応答がどのような年齢変化を示すかを検討した。6歳児15名(男9名・女6名)、5歳児16名(男9名・女7名)、および4歳児14名(男7名・女7名)を被験者とした。高周波数刺激での後傾は、全被験者に認められた。低周波数刺激での前傾は、6歳児で67%、5歳児で19%、4歳児で14%の被験者に認められた。4,5歳児に前傾が認められたのは、女子のみであった。応答時間は、6歳児では、後傾1.7±1.2秒、前傾2.9±1.9秒、5歳児では、後傾1.4±1.1秒、前傾3.2±2.0秒、および4歳児では、後傾1.1±1.0秒、前傾1.7±0.1秒であった。これらの結果から、(1)年齢が進むにつれて参照系が形成されること、(2)女子の方がその形成が早いこと、および(3)反応のための参照系は存在するが、各感覚のマッチング機能は未完成であることが明らかとなった。研究課題/領域番号:18650168, 研究期間(年度):2006 – 2008出典：「体性感覚刺激強度・速度の違いによる姿勢応答特性及びその発達的変化」研究成果報告書　課題番号18650168（KAKEN：科学研究費助成事業データベース（国立情報学研究所））（https://kaken.nii.ac.jp/ja/grant/KAKENHI-PROJECT-18650168/)を加工して作

支持機能に焦点を当てた安静立位姿勢と歩行姿勢との関係についての検討

金沢大学医学部立位姿勢の保持様式が、歩行様式を強く規定していると考えられる。そこで、安静立位時の身体各部位の幾何学的相互関係と支持規定面内の前後重心位置を求めるとともに、歩行時の立脚相における前後方向の床反力がゼロとなる時点の前後重心位置と身体各部位の幾何学的相互関係を求め,それらの相関関係並びに下腿筋の活動様式について検討した。大学生男子100名の中から安静立位時における前後重心位置が30〜40%(B群)、40〜50%(M群)、50〜60%(F群)に分布する者を10名ずつ選出した。その被験者に対して、周期1.0Hz、歩幅73cmで全長10mの歩行を課し、左脚立脚支持期の床反力、身体側面のアライメント、およびヒラメ筋と前脛骨筋の間で筋活動の交替が生じる足圧中心位置を測定した。アライメントはビデオ画像から、外果点と大転子点および大転子点と肩峰点を結ぶ線の重心線とのなす角度の和(前傾度)によって評価した。結果:安静立位時における前傾度はB群(mean0.5±SD3.63度)、M群(3.6±1.84度)、F群(5.9±2.08度)であり有意差が認められた。歩行時に下腿筋に活動交替が生じる足圧中心位置は、B群(36.5±6.87%)、M群(33.8±4.57%)、F群(33.9±5.64%)であり有意差が認められなかった。同じく床反力の前後成分がゼロになる時点の前後重心位置は、B群(47.6±3.80%)、M群(51.7±3.58%)、F群(52.6±2.67%)であり、安静立位時の前後重心位置との間にr=0.563の有意な相関が認められた。また同時点の前傾度は、B群(6.0±3.28度)、M群(10.5±2.40度)、F群(11.8±2.69度)であり、安静立位時の前傾度との間にr=0.607の有意な相関が認められた。研究課題/領域番号:08680103, 研究期間(年度):1996出典：研究課題「支持機能に焦点を当てた安静立位姿勢と歩行姿勢との関係についての検討」課題番号08680103（KAKEN：科学研究費助成事業データベース（国立情報学研究所）） （https://kaken.nii.ac.jp/ja/grant/KAKENHI-PROJECT-08680103/）を加工して作

Postural muscle activity patterns during standing at rest and on an oscillating floor

金沢大学大学院医学系研究科環境社会医学Postural muscle activity pattern was examined in the eyes-closed state after adequate adaptation to floor anteroposterior oscillation. Twenty-three subjects were grouped almost evenly according to dominance of anterior or posterior postural muscles in the trunk and thigh during quiet stance. In the posterior-dominant group, this dominance was maintained at every frequency in most subjects. In the anterior-dominant group, this dominance was maintained in most subjects at 0.1 and 0.5 Hz but changed to posterior dominance at 1.0 and 1.5 Hz in about half the subjects. Periodicity of muscle activity was evaluated by EMG amplitude spectrum at the floor oscillation frequency. Periodicity of posterior-dominant muscles in the trunk and thigh increased with increasing oscillatory frequency. In the trunk, the periodicity did not differ significantly between posterior-dominant and anterior-dominant groups. However, in the thigh, periodicity was significantly lower in the anterior-dominant muscles. This was considered to be caused by nonperiodic alternating action of the anterior and posterior muscles. In the lower leg, posterior dominance was observed in quiet stance and at all oscillation frequencies. Periodicity of soleus and gastrocnemius increased at higher frequencies and was higher in gastrocnemius than in soleus. The periodicity difference between both muscles decreased with increasing oscillation frequency. © 2005 Elsevier Ltd. All rights reserved

Quantitative analysis of the Trendelenburg test and invention of a modified method

Background While the Trendelenburg test has been used for 120 years to detect hip abductor muscle weakness, the methodology has not been standardised. Purposes This study undertook to quantitatively analyze the relation between abductor muscle activity and pelvic tilt angle in the Trendelenburg one-leg stance, examine the pitfalls associated with performing the T-test, and develop a modified method that will produce reliable results. Methods A convenience sample of 15 healthy males was asked to assume a one-leg stance in ten different postures, five with mild flexion on the unsupported side, and five with severe flexion. Trunk sway angle, pelvic tilt angle, and the pelvic on femur (POF) angle were measured for each posture. Statistical analysis was used to assess differences in hip abductor activity and public tilt angle between the control posture and the test postures. Results With minimum trunk sway, hip abductor muscle activity increases when the pelvis is elevated and decreases when it is dropped. With trunk sway toward the test side, abductor muscle activity decreased when the pelvis was elevated; with trunk sway toward the non-test side, muscle activity stayed approximately constant when the pelvis was dropped. Conclusions Based on the results we developed a modified T-test methodology that would improve reliability. This test should be performed with minimum trunk sway and severe flexion on the non-test side. The assessment of muscle weakness is based on whether the patient can keep the single-leg standing posture when forced to elevate the pelvis, not simply on the pelvic drop. In future research, we will perform the modified T-test on patients with a suspected hip abductor deficiency, and assess the usefulness of the modified test. © 2016 The Japanese Orthopaedic Associatio

Very Low Nucleation Rates of Glucose Isomerase Crystals under Microgravity in the International Space Station

In situ observation of the nucleation and growth of glucose isomerase (GI) crystals under microgravity was conducted using an optical microscope during the first flight of the Advanced Nano Step project undertaken in the International Space Station (ISS). Very low apparent nucleation rates (J’) of GI crystals in the solution and on the substrate of the growth container were confirmed compared with those on the ground. In particular, J’ of GI crystals in the solution were a few times lower than that on the substrate. The growth rates (R) of the {101} faces of GI crystals on the substrate and the apparent growth rates (R’) in the solution were measured. The very low nucleation rates allowed us to successfully measure R at a very high supersaturation region (up to ln(C/Ce) = 6), at which R cannot be measured on the ground