We investigated the intervention effect of training using a feedback-type tactile discrimination system on sensorimotor dysfunction of the hand after a stroke. A human male subject with sensorimotor dysfunction in his left hand after a stroke was asked to perform peg manipulation practice, a building block stacking task, and a material identification task for 10 min each for six weeks. During the activities, a tactile discrimination feedback system was used. The system is a device that detects the vibration information generated when touching an object with a hand and that feeds back the captured information in real time as vibration information. After the intervention, in addition to the reorganization of the sensorimotor areas, the deep sensation, sense of agency, numbness, amount of use, and quality of the left-hand movement improved. Our results suggest that training with the use of a feedback system could be a new form of rehabilitation for sensorimotor dysfunction of the hand.

Background/Objectives: This study evaluated the effects of a tactile-discrimination compensatory real-time feedback device on hand sensorimotor function in cervical spinal cord injury patients. The study assessed changes in hand numbness, dexterity, and electroencephalogram (EEG) activity, particularly γ-wave power in the sensorimotor area during skilled finger movements. Methods: Three patients with cervical spinal cord injury who presented with hand sensorimotor dysfunction underwent treatment with this device. All cases underwent the intervention using an AB design; A is the exercise task without the system device, and B is the exercise task under the system device. To confirm the reproducibility and minimize the influence of confounding factors, a multiple-baseline design, in which the intervention period was staggered for each subject, was applied. To determine efficacy, the hand numbness numerical rating scale, peg test, and EEG were measured daily, and Tau-U calculations were performed. Results: In two of three cases, moderate or very large changes were observed in numbness in B. In all cases, there was a large or very large change in the peg test results in the B. Regarding EEG activity, the non-skilled participants showed amplification of γ-wave power in the sensorimotor area during the B. Conversely, in the skilled participants, the γ-wave power of the sensorimotor area was attenuated during skillful movements. Conclusions: These findings indicate that the ability of the brain to compare and align predictive control with sensory feedback might be compromised in patients with damage to the afferent pathways of the central nervous system. Moreover, the use of this device appears to have played a role in supporting functional recovery.

Background/Objectives: Post-stroke impairment (PSI) frequently causes upper limb sensorimotor deficits, including reduced ability to perceive fingertip friction, limiting dexterous movements. We evaluated the effects of a tactile sensory substitution device (“Yubi-Reco”) that delivers real-time fingertip friction information to both temporal bones via vibration and explored potential neurophysiological changes in PSI. Methods: This study used a single-case experimental multiple-baseline design. Three participants with PSI completed a 15-day AB-phase protocol. Baseline (A) consisted of daily sensorimotor tasks without Yubi-Reco, while the intervention (B) added real-time friction feedback via Yubi-Reco to the same tasks. Outcomes included electroencephalography (gamma power), the Purdue Pegboard Test, finger numbness Numerical Rating Scale (NRS), Motor Activity Log-14 (Amount of Use [AoU], Quality of Movement [QoM]), and sense of agency (SoA). Effect sizes were calculated using Tau-U. Results: Very large changes were observed in Purdue Pegboard Test performance (Tau-U = 0.80), and large changes were observed in finger numbness NRS scores (Tau-U = 0.79). Case I showed increased gamma power across frontal and central sites, Case II demonstrated relative attenuation near right frontal and parietal sites, and Case III showed bilateral central gamma reduction, suggesting neurophysiological alterations near recorded sites. AoU and SoA improved in all participants. AoU exceeded the minimal clinically important difference (0.5 points) in two cases. Conclusions: Real-time sensory substitution feedback using Yubi-Reco may improve upper-limb sensorimotor function and induce preliminary neurophysiological changes in individuals with PSI. The intervention appeared to enhance dexterous movement ability and SoA, which coincided with preliminary, exploratory neurophysiological shifts across sensorimotor networks.

Total Knee Arthroplasty（TKA）後の問題点に，遊脚初期膝周囲筋の筋活動により，遊脚期膝関節屈曲角度や歩行速度が低下しやすいことが挙げられる。そこで，左TKA 3 週時点で左遊脚期膝関節屈曲角度が正常値より不足している高齢女性に対し，前遊脚期の股関節最大伸展角度を検知することで，遊脚期膝関節屈曲運動を可能とする歩行アシスト装置を用いた介入を試みた。本研究では，左遊脚初期膝周囲筋の筋活動に着目し，その有効性について検証した。本介入はAB デザインとし，Ａは独歩練習も含めた歩行能力改善に推奨される理学療法を行った。Ｂは独歩練習時に歩行アシスト装置を駆動し，他はＡと同様の理学療法とした。Ｂ介入後，左遊脚初期に大腿直筋，外側広筋，大腿二頭筋の％ Maximal Voluntary Contraction（％ MVC）が低値傾向を示し，腓腹筋の％ MVCが高値傾向を示した。10ｍ歩行速度は中等度改善を認めた。歩行アシスト装置を用いた介入は，左遊脚期膝周囲筋の筋活動を変化させ，歩行速度を改善させる可能性が示唆された。