Norihide Itoh

[Purpose] Stand-and-ride personal mobility devices controlled by movements of the user's center of gravity are used for balance training. We aimed to describe the physical activity required to operate this type of mobility device. [Participants and Methods] Eleven healthy males performed the following tasks: 1) moving their center of gravity forward or backward while standing on the floor (control task) and, 2) moving the mobility device forward or backward by moving their center of gravity (experimental task). [Results] We observed that the displacement of the center of gravity and the center of pressure, as well as angular displacements of the hips and knee joints, and maximum muscle activities of the biceps femoris, the medial head of the gastrocnemius and peroneus longus muscles were lesser during the experimental than during the control task. The distance moved by the device was significantly greater than the displacement of the user's center of gravity during the experimental task. [Conclusion] We observed that moving the device forward or backward required lesser physical activity than that required to shift the user's center of gravity forward or backward while standing on the floor. Additionally, we observed that even a small displacement of the user's center of gravity produced a large displacement of the device. We concluded that during balance training, the greater and more easily perceived movement of the mobility device would provide helpful feedback to the user.

[Purpose] The balance exercise assist robot is a training device based on a personal transport assistance robot ridden in the standing position. The personal transport assistance robot uses an inverted pendulum control system and moves in response to movements of the user's center of gravity. The purpose of this study was to describe the characteristics of postural control during the action of stopping the personal transport assistance robot. [Participants and Methods] Eleven healthy male participants were required to maintain a standing position for 30 s; each task was performed 10 times. The measurement conditions were as follows: (1) on the floor; (2) on the robot, touching the handlebars; and (3) on the robot, not touching the handlebars. [Results] During the robotic tasks, the total locus lengths of the center of gravity and total joint momentums of the hip, knee, and ankle joints were larger, and the amount of displacement of the center of pressure was smaller than that during the floor task. Posture control on the robot was performed actively by mechanical interaction of the ankle, knee, and hip joints within a small base of support. [Conclusion] The balance exercise assist robot can be useful for postural control exercises because maintaining a standing position on the personal transport assistance robot required active postural control.

[Purpose] The Gait Exercise Assist Robot (GEAR) is a stationary, one-leg robot for gait training. The purpose of this case study was to evaluate the efficacy of rehabilitation using GEAR training for chronic stroke hemiplegia. [Participant and Methods] The participant was a 66-year-old male stroke survivor with left hemiparesis due to a right putaminal hemorrhage. He could walk slowly under supervision, although his gait had a constant forward trunk lean, with flexed knee, and a lack of hip extension movement on the affected side. Gait training using GEAR and physical therapy were performed for 14 days. Under both training conditions, the physical therapist made the participant conscious of extension movement of the hip joint in the affected-side stance phase. The robotic assistance was adjusted to maximize voluntary movement while observing gait. Physical function and gait ability parameters were evaluated before and after training. [Results] After training, extension motion of the hip joint increased in the affected-side stance phase, and body weight was transferred smoothly onto the affected-side limb, leading to an improvement in gait speed. [Conclusion] Gait training using GEAR and physical therapy may improve gait pattern and speed in patients with chronic stroke hemiplegia.

© 2017, © 2017 Informa UK Limited, trading as Taylor & Francis Group. Purpose: To establish the within-day and between-day intra-rater reliability, inter-rater reliability, validity and systematic errors of the tandem gait test (TGT). Materials and methods: Thirty participants performed the TGT and the timed up and go test (TUG) twice on the first day. Three independent raters measured these tests. After two weeks, the protocol was repeated by one tester to assess between-day reliability. The within-day and between-day intra-rater reliability was estimated by intraclass correlation coefficient (ICC) and Bland–Altman plots to assess systematic errors associated with the learning effect. Inter-rater reliability was estimated by ICC and minimum detectable change at 95% confidence. Concurrent validity was assessed by examination of the correlation between TGT and TUG using Pearson’s correlation coefficient. Results: Within-day and between-day intra-rater reliability were good (ICC > 0.9 and ICC > 0.7). The Bland–Altman plots showed systematic error in the between-day measurements. Inter-rater reliability was supported by strong values for ICC (ICC > 0.9). The Pearson’s correlation coefficient between the TGT and TUG showed a significant positive correlation (r > 0.67, p <.001). Conclusions: These results show that the learning effect of the TGT might be a considerable factor when interpreting follow-up measurements after a few days.

Three-dimensional gait analysis (3DGA) is shown to be a useful clinical tool for the evaluation of gait abnormality due to movement disorders. However, the use of 3DGA in actual clinics remains uncommon. Possible reasons could include the time-consuming measurement process and difficulties in understanding measurement results, which are often presented using a large number of graphs. Here we present a clinician-friendly 3DGA method developed to facilitate the clinical use of 3DGA. This method consists of simplified preparation and measurement processes that can be performed in a short time period in clinical settings and intuitive results presentation to facilitate clinicians' understanding of results. The quick, simplified measurement procedure is achieved by the use of minimum markers and measurement of patients on a treadmill. To facilitate clinician understanding, results are presented in figures based on the clinicians' perspective. A Lissajous overview picture (LOP), which shows the trajectories of all markers from a holistic viewpoint, is used to facilitate intuitive understanding of gait patterns. Abnormal gait pattern indices, which are based on clinicians' perspectives in gait evaluation and standardized using the data of healthy subjects, are used to evaluate the extent of typical abnormal gait patterns in stroke patients. A graph depicting the analysis of the toe clearance strategy, which depicts how patients rely on normal and compensatory strategies to achieve toe clearance, is also presented. These methods could facilitate implementation of 3DGA in clinical settings and further encourage development of measurement strategies from the clinician's point of view.

Objective: Spatio-temporal parameters are typically used for gait analysis. Although these parameters are measured by sophisticated systems such as 3D motion capture system or optoelectronic bars, these systems cannot be deployed easily because of their high costs, large space requirements and elaborate set-up. The purpose of this study is to develope a system for measuring spatiotemporal gait parameters using a laser range scanner during treadmill gait. Approach: To calculate accurate spatiotemporal parameters, the differences between the laser range scanner measured values and the reference values obtained from a 3D motion capture system were investigated in thirty subjects. From measurements in time and position at foot contact/off, adjustments to compensate for the differences in time and position were derived. Then, to determine the validity of the proposed system, values from the proposed system and the reference system were compared in four additional subjects. Main results: The results indicate that the data from the laser range scanner demonstrate certain differences in time and position compared with reference values. However, when compensation values were introduced, each spatiotemporal parameter correlated well with the reference values.

[Purpose] To clarify the changes in postural strategy by evaluating leg joint motion and muscle activity before and after continuous exercise against perturbation using the Balance Exercise Assist Robot (BEAR). [Subjects and Methods] Nine healthy subjects (male 7, female 2 mean age 23 ± 1 years) performed a postural perturbation coping exercise only. In the task, the robot leaned and moved automatically. Participants were instructed to maintain their default upright position and they performed the exercise five times in a row (1 minute/trial). Changes in total movement distance, range of motion of each joint (hip, knee, ankle), and mean activity of each muscle for the first and fifth trials were compared. [Results] The total movement distance of BEAR and range of motion in the hip decreased significantly from the first trial to the last trial. No change in muscle activity was observed in the rectus femoris, biceps femoris, tibialis anterior or gastrocnemius. [Conclusion] The results for exercise against perturbation using BEAR in this study suggest that BEAR may be a promising method to improve the ankle strategy for maintaining a standing posture.

BACKGROUND: In a patient with severe hemiplegia, the risk of the knee giving way is high during the early stage of gait exercise with an ankle-foot orthosis. However, use of a knee-ankle-foot orthosis has many problems such as large amount of assistance and compensatory motions. To resolve these problems, we have engaged in the development of the Gait Exercise Assist Robot (GEAR). OBJECTIVE: To evaluate the improvement efficiency of walk with GEAR in a stroke patient. METHODS: The subject was a 70-year-old man presented with left thalamus hemorrhage and right hemiplegia. The patient underwent exercise with the GEAR 5 days a week, for 40 minutes per day. We evaluated the Functional Independence Measure score for walk (FIM-walk score) every week. The control group consisted of 15 patients aged 20-75 years with hemiplegia after primary stroke, who had equivalent walking ability with the subject at start. As the primary outcome, we defined improvement efficiency of FIM-walk, which was gain of FIM-walk divided the number of required weeks. RESULTS: Improvement efficiency of FIM-walk of the subject was 1.5, while that of control group was 0.48 +/- 3.2 (mean +/- SD). CONCLUSIONS: GEAR is potentially useful for gait exercise in hemiplegic patients.

【目的】バランス練習アシスト(BEAR)はロボット技術を用いたバランス練習機器である.今回,BEAR使用中の下肢筋活動の特徴を明らかにすることを目的とした.【方法】健常成人7名を対象とし,重心移動課題のテニスとスキー,外乱対処課題のロデオからなる3種類のゲームを,4段階の難易度で1ゲームあたり90秒間ずつ施行した.表面筋電図は両側の大臀筋,中臀筋,大腿直筋,内側広筋,大腿二頭筋,前脛骨筋,腓腹筋,長腓骨筋を用い,筋積分値から平均筋活動量を算出した.【結果】各ゲームの筋活動量は難易度の上昇に伴い増加し,ゲーム間の筋活動量を比較すると,前脛骨筋ではロデオがテニス(p=.009)とスキー(p=.017)より大きく,腓腹筋ではロデオがスキーより大きく(p=.045),長腓骨筋ではスキーがテニスより大きかった(p=.041).【結論】BEARは難易度の変更により下肢筋への負荷の調整が可能であり,3種類のゲームはそれぞれ異なる下肢筋活動を促すことが可能であった.(著者抄録)

【目的】本研究の目的は,トレッドミル歩行の三次元動作分析で表現できるリサージュ図形を用いたリサージュ概観図(LOP)の有用性を検討することである.【方法】健常者19名,片麻痺患者2名,変形性股関節症患者1名を対象に三次元トレッドミル歩行分析を実施し,LOPを作成した.また,歩行分析に熟練した理学療法士3名が患者3名の歩行を視診で評価した.健常者のリサージュ図形は平均化し,作成した健常者グランドアベレージLOPと患者3名を比較した.【結果】患者のLOPは,片麻痺者で遊脚期の分回し,トゥクリアランス低下,骨盤挙上,立脚期の内側ホイップを,変形性股関節症患者では両側性デュシェンヌ徴候,立脚期の過剰な膝関節の屈曲など視診で認めた所見に加え,視診のみでは観察できなかった多数の所見を表していた.【結論】各肢節の運動パターンだけでなく肢節間の位置関係から姿勢や対称性といった歩行の全体像を理解できた.(著者抄録)

Background: The efficacy of botulinum toxin A (BoNTA) injection on spasticity is usually measured using Modified Ashworth Scale (MAS), but this only evaluates muscle tone at rest and has poor reliability. There are no reports that quantitatively evaluate pes varus during walking after botulinum treatment. The purpose of this study was to evaluate the efficacy of BoNTA injection on pes varus during gait using 3-dimensional motion analysis. Methods: Twenty-four hemiplegic patients with spastic pes varus deformity during gait received BoNTA injection into lower limb muscles. MAS score, comfortable overground gait velocity, and pes varus angle during treadmill walking were evaluated before, 2, 6, and 12 weeks after the injection. Five healthy subjects were also recruited to develop the pes varus/valgus angle as a normal reference. Results: The median MAS scores were significantly lower at 2 and 6 weeks after the injection. The maximum pes varus angle during the swing phase was significantly lower at 2, 6, and 12 weeks after the injection. It was significantly lower at 6 weeks after the injection during stance phase. The comfortable overground gait velocity was also improved after the injection. However, 2 patients experienced pain during gait and their pes varus angle increased during the follow-up period. Conclusions: BoNTA injection improved pes varus angle during gait. Evaluating motion in addition to spasticity at rest is recommended because improvements in limb function do not always parallel improvements in spasticity at rest.

Objectives: To develop effective electrical stimulation treatment to reduce spasticity, we examined the optimal stimulus point of the common peroneal nerve. Materials and Methods: The locations of selective stimulus points for the deep peroneal nerve or superficial peroneal nerve fiber were examined in 25 healthy subjects in both legs (50 legs) using the ratio of the tibialis anterior (TA) to the peroneus longus (PL) M-wave amplitude (TA/PL ratio). In addition, we measured reciprocal Ia inhibition in ten healthy subjects. The amount of inhibition was determined from short-latency suppression of the soleus (Sol) H-reflex by conditioning stimuli to the deep or superficial peroneal nerve. The paired t-test was used for statistical analysis. Results: The mean TA/PL ratio during deep peroneal nerve stimulation was significantly different from superficial peroneal nerve stimulation (p < 0.001). The mean stimulus point for the deep peroneal nerve was located 7 +/- 5mm distal and 3 +/- 6mm anterior from the distal edges of the head of fibula and was markedly different from the stimulus point for the superficial peroneal nerve (20 +/- 7mm distal and 12 +/- 8mm posterior). During deep peroneal nerve stimulation, the mean conditioned H-reflex was depressed to 83.8 +/- 10.7% of the unconditioned value of the H-reflex. In contrast, during superficial peroneal nerve stimulation, the mean conditioned H-reflex increased to 105.3 +/- 5.2%. These values were significantly different (p < 0.001). Conclusions: In the present study, we revealed a stimulus area of the deep peroneal nerve. Also, we observed the inhibitory effects of stimulation upon the deep peroneal nerve at individual stimulus point. Our results appear to indicate that localized stimulation of the deep peroneal nerve is more useful for the reduction of ankle spasticity.

Objective: To examine the efficacy of postural strategy training using a personal transport assistance robot (PTAR) for patients with central nervous system disorders. Design: Single-group intervention trial. Setting: Rehabilitation center at a university hospital. Participants: Outpatients (N=8; 5 men, 3 women; mean age, 50 +/- 13y) with a gait disturbance (mean time after onset, 34 +/- 29mo) as a result of central nervous system disorders were selected from a volunteer sample. Interventions: Two methods of balance exercise using a PTAR were devised: exercise against perturbation and exercise moving the center of gravity. The exercises were performed twice a week for 4 weeks. Main Outcome Measures: Preferred and tandem gait speeds, Functional Reach Test, functional base of support, center of pressure (COP), muscle strength of lower extremities, and grip strength were assessed before and after the completion of the exercise program. After the exercise program, enjoyment of exercise was investigated via a visual analog scale questionnaire. Results: After the program, statistically significant improvements were noted for tandem gait speeds (P=.009), Functional Reach Test (P=.003), functional base of support (P=.014), and lower extremity muscle strength (P<.001-.042). On the other hand, preferred gait speeds (P=.151), COP (P=.446-.714), and grip power (P=.584) did not change. Finally, subjects rated that this exercise was more enjoyable than traditional balance exercises. Conclusions: Dynamic balance and lower extremity muscle strength were significantly improved in response to postural strategy training with the PTAR. These results suggest that postural strategy training with the PTAR may contribute to fall prevention of patients with a balance disorder. Archives of Physical Medicine and Rehabilitation 2013;94:59-66 (C) 2013 by the American Congress of Rehabilitation Medicine

The purpose of present study is to estimate the optimal stimulus intensity envelope for drop foot rehabilitation based on a kinetic perspective. The voluntary and electric-stimulated elicited dorsiflexion torque responses of 11 healthy subjects were measured. During dorsiflexion, we recorded the tibialis anterior (TA) electromyography (EMG) or the stimulation intensity at four angles of the ankle joint. From these measurements, we derived two approximate equations that estimate dorsiflexion produced by either voluntary contraction or by electrical stimulation using a sigmoid function and a stepwise-regression analysis. We then tested the predictive capability of the model using Pearson correlation. Both equations indicated high correlation coefficients. Finally, we derived a relation between the TA EMG amplitude and stimulation intensity. From the obtained equation, we determined the optimal stimulus amplitude. We assume that the derived stimulus intensity envelope, calculated from EMG amplitude and angle of ankle joint, satisfies kinetic demand. © 2012 Informa UK, Ltd.

Itoh N, Kagaya H, Saitoh E, Ohtsuka K, Yamada J, Tanikawa H, Tanabe S, Itoh N, Aoki T, Kanada Y. Quantitative assessment of circumduction, hip hiking, and forefoot contact gait using Lissajous figures. Jpn J Compr Rehabil Sci 2012; 3: 78-84.<BR>Objective: To quantitatively assess gait abnormalities using Lissajous figures obtained from three-dimensional motion analysis of treadmill gait, with the goal of applying the findings to the treatment of gait disorders.<BR>Methods: Thirty-nine healthy subjects and 30 hemiplegic patients were studied. Treadmill gait analysis was conducted using a three-dimensional motion analysis system. Using the Lissajous figures obtained from the gait analysis, quantitative indexes were developed for three gait abnormalities: circumduction, hip hiking, and forefoot contact. The indexes were validated through comparison with observational assessment by physiotherapists with expertise in gait analysis. <BR>Results: The values obtained for all the indexes were significantly higher in hemiplegic patients compared to healthy subjects (p < 0.001). Correlation analysis was conducted between the index values and observational scores for each gait abnormality, yielding Spearman's rank correlation coefficients of -0.82 for circumduction, -0.64 for hip hiking, and -0.84 for forefoot contact (p < 0.001).<BR>Conclusion: We successfully developed objective quantitative indexes for gait abnormalities, which were not influenced by rater bias.