This study aimed to validate the effectiveness of the Articulation Motion Assessment System (AMAS), a joint kinematic evaluation system, for clinical applications. AMAS enables synchronised measurement using neurophysiological indicators, overcoming laboratory setting limitations. We compared AMAS-based ankle joint kinematic evaluations, particularly the sagittal and frontal plane angles, with two-dimensional (2D) motion analysis to determine the validity and reliability of AMAS. Both AMAS and 2D motion analysis reliably detected significant differences in angles within the sagittal and frontal planes. Correlation analysis revealed a significant moderate-to-strong correlation between the AMAS and the conventional method of 2D motion analysis, proving the measurement validity of the AMAS (ρ = 0.53–0.77 for sagittal plane angles; ρ = 0.46–0.72 for frontal plane angles). The average root mean squared error (RMSE) was significantly lower in AMAS (10.90 ± 2.93° for sagittal plane angles; 13.44 ± 1.09° for frontal plane angles) than in the inertial sensor-based three-dimensional (3D) motion analysis. Reliability analysis revealed high reliability of measurements (intraclass correlation coefficients (ICC) ≥ 0.76). However, the Bland–Altman analysis identified a slightly lower fixed bias, which was observed as a characteristic of each measurement system. The AMAS accurately detects ankle joint angles without being constrained by measurement environment limitations. Synchronised measurements using neurophysiological indicators potentially contribute to understanding ankle joint control mechanisms and developing rehabilitation strategies.

Background/Objectives: This study aimed to examine the influence of brain activity during motor preparation on walking ability, focusing on motor control during active ankle dorsiflexion. Methods: Participants were classified into high- and low-corticomuscular coherence (CMC), an index of neuromuscular control based on the median value. Biomechanical and neurophysiological indices of active ankle dorsiflexion and walking ability were compared between the two groups. Additionally, a machine learning model was developed to accurately predict the CMC classification using brain neural activity during motor preparation. Results: The Cz-TA CMC (beta frequency band) during active ankle dorsiflexion successfully detected significant differences in the maximum dorsiflexion angle, inversion angular velocity, brain activity localization, and variations in Cz beta power values during the transition from motor preparation to execution. Furthermore, CMC identified significant differences in dorsiflexion angle changes after toe-off and inversion angles at initial contact during gait. A support-vector machine model predicting high or low CMC demonstrated high accuracy (Accuracy: 0.96, Precision: 0.92–1.00, Recall: 0.91–1.00, F1 Score: 0.95–0.96) during motor execution based on beta power values from −500 to 0 ms prior to the initiation of active ankle dorsiflexion (representing motor preparation). Conclusions: These findings highlight that the motor preparation processes of the brain during active ankle dorsiflexion are involved in walking ability and can be used to predict it. This indicator is independent of disease severity and holds the potential to provide a clinically versatile evaluation method.

Body awareness, which comprises the sense of body possession and action ownership, is essential for the adaptive movement of humans in response to external environments. However, existing body cognition assessments include many overt elements of cognitive functional activity, but no assessment captures the latent body cognition necessary for exercise and daily life activities. Therefore, this study aimed to devise a body cognition assessment system (BCAS) to examine the functional basis of body cognition in healthy participants and investigate its usefulness. The BCAS was used to assess body cognition on three occasions, and BCAS values were calculated from the results of the assessment. The intraclass correlation coefficient (ICC) was used to determine reproducibility. Neural activity in the brain during somatocognition assessment while conducting the BCAS was measured by electroencephalogram. Moreover, the functional basis for somatocognition with the BCAS was also investigated. The results demonstrated that the BCAS values varied across the three administrations (ICC (1.3) = 0.372), and changes in the state of neural activity in the brain were observed. The results suggest that assessment using the BCAS may be a new indicator of ever-changing body cognition.

Active ankle dorsiflexion (AAD) has been proposed as a surrogate measure for gait-related motor control. However, whether the neural coupling between motor preparation and execution during AAD predicts gait ability remains unclear. This study examined whether μ–γ coupling was evaluated as a practical neurophysiological marker of gait performance. In this study, 12 healthy adults and 4 patients with chronic stroke performed an AAD task and an overground walking task. Ankle kinematics, surface electromyography, and electroencephalography were simultaneously recorded. Corticomuscular coherence (CMC) and phase–amplitude coupling (PAC) were analyzed as indices of motor preparation–execution coupling. Gait performance was assessed based on gait speed and a Gait Assessment and Intervention Tool (G.A.I.T.). Patients with stroke showed significantly lower gait speed (0.60 vs. 1.24 m/s, p < 0.001) and G.A.I.T. scores compared to controls. In the AAD task, patients with stroke exhibited significantly reduced ankle angular velocity and lower CMC between Cz and the tibialis anterior compared to controls (p < 0.05). Source localization revealed diminished activity in the middle temporal gyrus, inferior parietal lobule, and insula in patients with stroke. Notably, the PAC-derived modulation index (MI) at Cz was markedly reduced in patients with stroke (0.03) compared to controls (1.50, p < 0.001), clearly discriminating between the groups. Motor preparation–execution coupling during AAD strongly reflects gait capacity after stroke. PAC-MI is a novel neurophysiological marker; requires validation biomarker for the early and objective evaluation of gait-related motor control with potential utility in stroke rehabilitation.

Ankle dorsiflexion plays a vital role in ensuring safe and effective walking post-stroke, yet the best methods for assessing it and their clinical significance are still uncertain. This research compiles the existing sensor-based technologies used to measure ankle dorsiflexion in adults who have experienced a stroke and examines how these measurements correlate with walking performance. It also compares these findings with traditional clinical evaluation methods like manual muscle testing (MMT). We conducted a systematic search of PubMed, IEEE Xplore, and the Cochrane Library (2000–2025) for both observational and experimental studies that utilized sensor-based techniques (such as handheld or isokinetic dynamometry, load cells, and proprioceptive devices) to quantify ankle dorsiflexion and reported their relationship with gait outcomes. Additionally, studies employing conventional, non-instrumented clinical grading (e.g., ankle-dorsiflexor MMT) were included if they explored the connection between ankle function and gait, although these were not included in the quantitative analysis. Eighteen studies involving 783 stroke survivors met the inclusion criteria and were evaluated using the Newcastle–Ottawa Scale. Generally, individual studies found a positive association between ankle-dorsiflexor strength and both gait speed and endurance, although some negative correlations were noted. The strength and sometimes direction of these associations varied depending on the sensing technology, dorsiflexion index, gait outcome, and stroke chronicity. Overall, the current evidence indicates a generally positive but highly variable relationship between ankle dorsiflexion measurements and gait post-stroke, emphasizing the need to identify sources of variability and to create standardized, clinically applicable sensor-based assessment protocols.