小山 総市朗

機能的電気刺激(FES)の中でも、随意運動介助型FESや傾斜センサ内蔵型FESは、脳卒中片麻痺患者の歩行障害改善への有効性が期待できる。本研究は、この2つのFESを併用することによって、歩行能力が改善し、運動関連領域の活動に変化があるのか検討した。対象者は回復期病棟に入棟した脳卒中患者5名とし、無作為に随意運動介助型FES+傾斜センサ内蔵型FESを用いた歩行練習群(実験群)と随意運動介助型FES+通常歩行練習群(対照群)に分けた。介入期間は2週間とした。介入効果は加速度計を用いた歩行時の身体動揺と、機能的磁気共鳴画像法を用いた随意的な足関節背屈運動時の脳活動で評価した。実験群では対照群と比較して、歩行速度の上昇、歩行時の身体動揺減少を認めた。脳活動は、実験群にのみ介入後に非麻痺側補足運動野(SMA)の有意な活動が認められた。本研究は随意運動介助型FESと傾斜センサ内蔵型FESを併用することで、非麻痺側SMAの賦活とともに歩行時の身体動揺を減少する可能性が示唆された。(著者抄録)

<jats:title>Abstract</jats:title><jats:p>Transcranial direct current stimulation (TDCS) can modulate motor cortical excitability. However, its after-effects are highly variable between individuals. Individual cranial and brain anatomy may contribute to this variability by producing varying electric fields in each subject’s brain. Here we show that these fields are related to excitability changes following anodal TDCS of the primary motor cortex (M1). We found in two experiments (N=28 and N=9) that the after-effects of TDCS were proportional to the individual electric field in M1, calculated using MRI-based models. Individuals with the lowest and highest local electric fields in M1 tended to produce opposite changes in excitability. Furthermore, the effect was field-direction dependent and non-linear with stimulation duration or other experimental parameters. The electric field component pointing into the brain was negatively proportional to the excitability changes following 1 mA 20 min TDCS of right M1 (N=28); the effect was opposite after 1 mA 10 min TDCS of left M1 (N=9). Our results demonstrate that a large part of variability in the after-effects of motor cortical TDCS is due to inter-individual differences in the electric fields. We anticipate that individualized electric field dosimetry could be used to control the neuroplastic effects of TDCS, which is increasingly being explored as a treatment for various neuropsychiatric diseases.</jats:p>

BACKGROUND: The relationship between peak torque of the knee extensor muscles and gait speed was previously investigated in patients with chronic stroke, but whether the rate of force development (RFD), another indicator of muscle strength, affected gait speed remained unknown. OBJECTIVE: To clarify the relationships between the RFD of the knee extensor muscles over multiple time intervals and gait speed in patients with chronic stroke. METHODS: Twenty chronic stroke patients participated in this study. The RFD of affected and unaffected knee extensor muscles was measured. Time intervals of the RFD were set to 0-50 ms, 0-100 ms (100RFD), 0-200 ms (200RFD), and 0-300 ms (300RFD). Gait speed was assessed at comfortable and maximum pace. Pearson correlation coefficient (r) was used to analyze the relationships between RFD and gait speeds. RESULTS: The RFD of affected knee extensor muscles over all intervals was moderately correlated with both comfortable and maximum gait speeds, whereas only limited combinations (100, 200 and 300RFD with maximum gait speed) were correlated on the unaffected side. CONCLUSIONS: The present results suggest that various factors related to the RFD of affected knee extensor muscles, such as neural drive and muscle size, affect gait speed.

Background With the development of computer technology, computerized dynamic posturography provides objective assessments of balance and posture control under static and dynamic conditions. Although a force-instrumented treadmill-based balance assessment is feasible for balance evaluations, currently no data exists. Objective This study was undertaken to assess the reliability and validity of balance evaluations using a force-instrumented treadmill. Methods Ten healthy adults participated in evaluations using both the treadmill and the EquiTest. Four balance evaluations were conducted: Modified Clinical Test of Sensory Interaction on Balance, Unilateral Stance, Weight Bearing Squat, and Motor Control Test. Results All balance evaluations using the force-instrumented treadmill method shared good reliability (intraclass correlation coefficient ≥0.6). The Modified Clinical Test of Sensory Interaction on Balance, Unilateral Stance, and Weight Bearing Squat evaluations had a correlation of r &lt  0.5 with EquiTest, whereas the Motor Control Test balance evaluation had moderate correlations (r &gt  0.5) with the EquiTest. Conclusion The results demonstrated that all balance evaluations using the force-instrumented treadmill were reliable, and that the Motor Control Test evaluation was moderately correlated with the EquiTest. Therefore, the use of a force-instrumented treadmill in balance evaluations might provide a certain level of value to clinical practice.

[Purpose] To create a regression formula in order to estimate 1RM for knee extensors, based on the maximal isometric muscle strength measured using a hand-held dynamometer and data regarding the body composition. [Subjects and Methods] Measurement was performed in 21 healthy males in their twenties to thirties. Single regression analysis was performed, with measurement values representing 1RM and the maximal isometric muscle strength as dependent and independent variables, respectively. Furthermore, multiple regression analysis was performed, with data regarding the body composition incorporated as another independent variable, in addition to the maximal isometric muscle strength. [Results] Through single regression analysis with the maximal isometric muscle strength as an independent variable, the following regression formula was created: 1RM (kg)=0.714 + 0.783 × maximal isometric muscle strength (kgf). On multiple regression analysis, only the total muscle mass was extracted. [Conclusion] A highly accurate regression formula to estimate 1RM was created based on both the maximal isometric muscle strength and body composition. Using a hand-held dynamometer and body composition analyzer, it was possible to measure these items in a short time, and obtain clinically useful results.

脳卒中患者の歩行能力改善はADL能力やQOLの改善に重要である。本研究は、随意運動や電気刺激治療の運動機能改善効果を促進するとされる経頭蓋直流電気刺激(tDCS)が、機能的電気刺激ペダリング運動の歩行能力改善効果を促進するか検証した。対象は初発脳卒中、年齢18歳から80歳、併存疾患なし、MMES 21点以上、10m連続歩行可能者とした。介入は5日間連続で、10分間のFESペダリング運動中、tDCS条件は損傷側一次運動野への2mAの陽極刺激を全期間、偽条件は初期15秒のみ行った。評価は10m歩行速度、6分間歩行距離、Timed Up and Go test(TUG)、Fugl-Meyer Assessment下肢項目、前脛骨筋筋力とした。期間中取り込み基準を満たした者は5名で、tDCS条件は6分間歩行距離とTUG(171.8±68.7mから194.0±75.0m、23.0±11.7秒から20.2±10.9秒)、偽条件はTUGのみ介入前後で有意な改善を認めた(21.6±10.2秒から18.6±9.0秒)。本結果は陽極tDCSの歩行耐久性改善寄与を示唆するが、臨床応用にはメカニズム解明が必要である。(著者抄録)

[Purpose] This study examined the contents of supervision needed by novice therapists to develop clinical abilities, focusing on their clinical experience and using an original evaluation table. [Subjects and Methods] An evaluation of clinical abilities basic attitudes, therapeutic skills, and clinical practice-related thoughts was conducted in 29, 21, and 9 therapists with clinical experience of 0–1 (1 year group), 1–2 (2 years group), and 2–3 (3 years group) years, respectively. [Results] There were no significant differences among the 3 groups in basic attitudes. Therapeutic skills markedly varied between the 1 and 3 years groups. In clinical practice-related thoughts, significant differences were observed between the 1 and 3 years groups and between the 2 and 3 years groups. [Conclusion] It may be appropriate for educators to provide technical education regarding skills that are achievable for students in the early stages in consideration of applied movements. Also, education for novices should be provided with importance attached to abilities influenced by clinical experience.

認知的負荷を含むSimon課題を使用した予測的姿勢制御について検討した。健常大学生11例(男性5名、女性6名、平均22±2歳)を対象とした。課題は、単純反応時間(SRT)課題、選択反応時間(CRT)課題、Simon課題とした。APAエラー率は、Simon課題不一致条件で他の3群に比較して有意に高値を示した。離地時間も、Simon課題不一致条件で3課題に比較して有意な遅延が見られると共に、Simon課題一致条件においてもSRT課題とCRT課題に比べ有意な遅延を示した。反応時間はエラー群で有意に早くなっており、主効果と交互作用が見られた。Simon課題一致および不一致条件においては有意な反応時間の短縮を示した。姿勢制御時間に関しては、逆にエラー群で有意な延長を示し、主効果と交互作用が見られた。離地時間は、エラーの有無または各条件による主効果が見られた。

下肢一次運動野(M1)への陽極経頭蓋直流電気刺激(tDCS)は、対側足関節運動機能を改善させるといわれている。しかし、半球間抑制の原理を用いた陰極刺激の効果は不明である。我々は、下肢M1への陰極刺激は同側足関節運動機能を改善させるという仮説を検証した。健常者は単盲検の3条件(陽極刺激、陰極刺激、偽刺激)で行った。課題はモニターに表示された目標波形の足関節底背屈運動でのトレースとし、介入、1時間後、24時間後に行った。陽極刺激は偽刺激より改善を認め(p=0.018)、陰極刺激は認めなかった(p=1.00)。1時間後と24時間後は両刺激ともに改善を認めなかった(p=0.14、p=1.00)。本結果はtDCSを用いたリハビリテーション治療の一助となると考える。(著者抄録)

<jats:p> When multiple sensory modalities are simultaneously presented, reaction time can be reduced while interference enlarges. The purpose of this research was to examine the effects of task-irrelevant acoustic accessory stimuli simultaneously presented with visual imperative stimuli on executive function during stepping. Executive functions were assessed by analyzing temporal events and errors in the initial weight transfer of the postural responses prior to a step (anticipatory postural adjustment errors). Eleven healthy young adults stepped forward in response to a visual stimulus. We applied a choice reaction time task and the Simon task, which consisted of congruent and incongruent conditions. Accessory stimuli were randomly presented with the visual stimuli. Compared with trials without accessory stimuli, the anticipatory postural adjustment error rates were higher in trials with accessory stimuli in the incongruent condition and the reaction times were shorter in trials with accessory stimuli in all the task conditions. Analyses after division of trials according to whether anticipatory postural adjustment error occurred or not revealed that the reaction times of trials with anticipatory postural adjustment errors were reduced more than those of trials without anticipatory postural adjustment errors in the incongruent condition. These results suggest that accessory stimuli modulate the initial motor programming of stepping by lowering decision threshold and exclusively under spatial incompatibility facilitate automatic response activation. The present findings advance the knowledge of intersensory judgment processes during stepping and may aid in the development of intervention and evaluation tools for individuals at risk of falls. </jats:p>

[Purpose] This study examined the effects of clinical training focusing on level-3 OSCE (analytical and therapeutic skills) items, and compared the achievement levels of physical (PT) and occupational (OT) therapist students. [Subjects] A total of 282 (165 PT and 117 OT) students enrolled at our university between 2008 and 2010 were studied. [Methods] OSCE scores were compared between before and after clinical training focusing on level-3 OSCE items, and between PT and OT students. [Results] Scores for 5 out of the 6 level-3a items were significantly higher after than before clinical training. Increases in scores of 2 or 3 level-3b and −3c items were also observed after clinical training. There were no marked differences between PT and OT students in scores for level-3a, −3b, and −3c items before clinical training. In contrast, after clinical training, OT students' scores for 3a and 3c items related to dressing were higher than those of PT students, and the latter's scores for 3b items related to transfer were higher than those of the former. [Conclusion] The results suggest level-3 OSCE items are effectively taught during clinical training.