Executive Functions Assessment Based on Wireless EEG and 3D Gait Analysis During Dual-Task: A Feasibility Study.

Executive functions (EFs) are neurocognitive processes planning and regulating daily life actions. Performance of two simultaneous tasks, requiring the same cognitive resources, lead to a cognitive fatigue. Several studies investigated cognitive-motor task and the interference during walking, highlighting an increasing risk of falls especially in elderly and people with neurological diseases. A few studies instrumentally explored relationship between activation-no-activation of two EFs (working memory and inhibition) and spatial-temporal gait parameters. Aim of our study was to detect activation of inhibition and working memory during progressive difficulty levels of cognitive tasks and spontaneous walking using, respectively, wireless electroencephalography (EEG) and 3D-gait analysis. Thirteen healthy subjects were recruited. Two cognitive tasks were performed, activating inhibition (Go-NoGo) and working memory (N-back). EEG features (absolute and relative power in different bands) and kinematic parameters (7 spatial-temporal ones and Gait Variable Score for 9 range of motion of lower limbs) were analyzed. A significant decrease of stride length and an increase of external-rotation of foot progression were found during dual task with Go-NoGo. Moreover, a significant correlation was found between the relative power in the delta band at channels Fz, C4 and progressive difficulty levels of Go-NoGo (activating inhibition) during walking, whereas working memory showed no correlation. This study reinforces the hypothesis of the prevalent involvement of inhibition with respect to working memory during dual task walking and reveals specific kinematic adaptations. The foundations for EEG-based monitoring of cognitive processes involved in gait are laid. Clinical and Translational Impact Statement: Clinical and instrumental evaluation and training of executive functions (as inhibition), during cognitive-motor task, could be useful for rehabilitation treatment of gait disorder in elderly and people with neurological disease.

Sagittal kinematics and imbalance of the spine and whole body during walking in late-onset Pompe disease.

Late-onset Pompe disease (LOPD) is characterized by postural abnormalities mainly due to involvement of paraspinal lumbar and abdominal-pelvic muscles. Previous studies quantitatively analyzed static upright posture, spatial-temporal parameters, and kinematics of the lower limbs and trunk, considered as single bone segment. Sagittal plane analysis of the spine and whole body during walking has never been investigated in patients with LOPD. The aim of the study was to evaluate sagittal kinematics and imbalance of the spine and whole body in patients with LOPD by three-dimensional (3-D)-motion analysis using an appropriate marker set protocol and introducing innovative kinematic parameters. Seven siblings with LOPD were assessed by 3-D-stereophotogrammetry using the DB-total protocol, which allows to analyze sagittal alignment of whole body. Fourteen age- and sex-matched healthy subjects were used as controls. LOPD group showed a flattening of the spinal curvatures, with a head and neck posteriorization with respect to sacrum, a significant increase of concavity in Heel-S2-Nasion/C7 angles, a rear-position of upper limbs with respect to pelvis, a shorter pendular activity, and a trend of elbow extension during ambulation. Moreover, a significant increase of excursion range in most of sagittal parameters was found. The present study highlighted a specific pathological postural pattern, resembling "man falling backwards," which reveals a biomechanical compensation strategy of patients with LOPD to maintain the balance against the instability of the spinopelvic region, kinematically verified by increase of the excursion ranges. DB-total kinematic parameters might be useful for functional evaluation and for monitoring response to enzyme replacement therapy, rehabilitation project, and disease progression.NEW & NOTEWORTHY This study is the first to quantitatively characterize the sagittal spine and whole body posture of patients with late-onset Pompe disease during walking, showing a pathological kinematic pattern defined "man falling backwards." 3-D-motion analysis, with a specific marker set (DB-total protocol) introducing new whole body kinematic parameters, may be useful for accurate functional evaluation and monitoring this rare disease.

Kinematic Evaluation of the Sagittal Posture during Walking in Healthy Subjects by 3D Motion Analysis Using DB-Total Protocol.

Posture can be evaluated by clinical and instrumental methods. Three-dimensional motion analysis is the gold standard for the static and dynamic postural assessment. Conventional stereophotogrammetric protocols are used to assess the posture of pelvis, hip, knee, ankle, trunk (considered as a single segment) and rarely head and upper limbs during walking. A few studies also analyzed the multi-segmental trunk and whole-body kinematics. Aim of our study was to evaluate the sagittal spine and the whole-body during walking in healthy subjects by 3D motion analysis using a new marker set. Fourteen healthy subjects were assessed by 3D-Stereophotogrammetry using the DB-Total protocol. Excursion Range, Absolute Excursion Range, Average, intra-subject Coefficient of Variation (CV) and inter-subject Standard Deviation Average (SD Average) of eighteen new kinematic parameters related to sagittal spine and whole-body posture were calculated. The analysis of the DB-Total parameters showed a high intra-subject (CV < 50%) and a high inter-subject (SD Average < 1) repeatability for the most of them. Kinematic curves and new additional values were reported. The present study introduced new postural values characterizing the sagittal spinal and whole-body alignment of healthy subjects during walking. DB-Total parameters may be useful for understanding multi-segmental body biomechanics and as a benchmark for pathological patterns.

Variability of Postural Stability and Plantar Pressure Parameters in Healthy Subjects Evaluated by a Novel Pressure Plate.

Background: Postural stability and plantar pressure parameters can be assessed by baropodometry; nevertheless, they are often affected by low repeatability. The aim of the study was to test the accuracy and repeatability of a novel resistive sensor pressure plate and to establish the most reliable baropodometric parameters. Methods: Accuracy and repeatability of the FM12050 BTS-Bioengineering plate measurements were assessed by using different weights in static conditions across three sessions. Subsequently, 20 healthy subjects were assessed by 30-s stabilometric analysis in bipedal standing with open eyes across four trials in two sessions, morning and afternoon. Results: Pressure plate repeatability in measuring the static weights was very high, and plate measurements were correlated to the scale measurements (Pearson's coefficient = 0.99). Percentage of load distribution between left and right foot and in rearfoot and forefoot regions showed the largest repeatability (coefficient of variation < 5%) across trials. Eventually, median and percentiles (25−75%) were reported for each parameter. Conclusions: This study helped to assess the accuracy and repeatability of a novel pressure plate in static conditions and to define the most reliable parameters for the assessment of postural stability and foot morphology. The present healthy-subject stabilometric dataset may be used as reference data in the evaluation of pathological populations.

Long-term effects of asymmetrical posture in boxing assessed by baropodometry.

BACKGROUND: Asymmetrical posture maintained over long training periods may affect phenotypic plasticity, resulting functional to sporting goal but negative to the locomotor system. Aim of this study was to quantitatively evaluate these long-term effects in competitive boxers. METHODS: Baropodometric analysis was used to assess 20 competitive boxers and 20 non-sportsmen in upright bipedal posture for 5 s and for 51.2 s with open (OE) and closed (CE) eyes. RESULTS: The boxers' group (BOX) showed a larger total foot load (TFL) (p=0.022) on the right foot and a larger rearfoot load (RfL) (P=0.011) on the left foot compared to non-sport controls (CTR). Moreover, a larger forefoot load (FfL) (P=0.001) on the right foot respect to left one was found in the BOX group, with the inversion of the RfL to FfL ratio (P=0.001) between two feet, while no significant differences were found in the CTR group. These findings, associated to a significantly larger center of foot angle (COF) in the BOX group, may indicate an anticlockwise rotation of the anatomical structures above the ankle joint of the right hemisoma respect to the left one, that appears to be consistent with the orthodox stance. Eventually, the BOX group showed a larger centre-of-pressure sway area (COPsa) in the OE condition than what measured in the CE and a significant difference in Romberg Index (BOX< CTR). CONCLUSIONS: The results of this study seem to confirm the theory of neuromuscular plasticity imprinted by the repetitive movements and long-lasting postures. Moreover, competitive boxers show an increase of proprioceptive function and a decrease of visual dependence on the postural control.

Quantitative Evaluation of Upright Posture by x-Ray and 3D Stereophotogrammetry with a New Marker Set Protocol in Late Onset Pompe Disease.

BACKGROUND: Late Onset Pompe Disease (LOPD) is a rare myopathy characterized by prevailing weakness of trunk and pelvic girdle muscles that causes motor disabilities. Spinal deformities have been reported unclearly on clinical examination. No study quantitatively assessed upright posture defining specific alterations of LOPD various phenotype. OBJECTIVE: Identify postural abnormalities in a homogeneous group of LOPD patients using 3D Stereophotogrammetry (St) and x-Ray (xR). METHODS: Seven LOPD siblings were recruited. They were assessed by clinical scales and, in upright posture, using xR and 3D-St with a new marker set protocol. Fourteen healthy individuals, age and sex-matched, were used as controls for St-parameters; normative xR-values were found in literature. RESULTS: LOPD patients showed a significant weakness of trunk and tibialis anterior muscles. Statistical analysis of St-parameters showed a larger ankle, knee, elbow, dorsal, S2-C7, heel-S2-C7, heel-S2-nasion angles and a lower sagittal vertical axis (SVA) than controls.xR-analysis highlighted an absence of scoliosis and a lower occipito-cervical, C2-C7 cervical and Cobb dorsal angles, and a trend to lower lumbar lordosis and SVA compared to normal values. Significant correlation was found in dorsal and lumbar angles calculated using xR-markers placed on spiny apophysis, xR-centre of vertebral bodies, Cobb-method and St-markers. CONCLUSION: This is the first quantitative study of postural abnormalities in LOPD patients using 3D-St and xR, highlighting sagittal standing alignment changes, difficult to assess to direct exam.Our new St-protocol showed a high reliability compared to xR. Further studies on larger population of LOPD might confirm the usefulness of these instrumental methods for monitoring disease course.

Short and long term effects of Nabiximols on balance and walking assessed by 3D-gait analysis in people with Multiple Sclerosis and spasticity.

BACKGROUND: Spasticity in people with Multiple Sclerosis (pwMS) is one of the most disabling symptoms on walking ability and balance. Among the systemic antispastic drugs, Nabiximols showed a good tolerability, safety profile and relevant efficacy. A few studies assessed long-term effects of this drug through clinical scales and instrumental tools, but no study investigated short-term effects. The aim of our study is to quantitatively evaluate the immediate effects of Nabiximols on walking and balance and their maintenance after 4 weeks in pwMS and spasticity. METHODS: pwMS were enrolled and randomized in 2 treatment groups: Sativex (SG) and control (CG) group. All patients were assessed at T0 (before the first Sativex puff), T1(after 45 minutes) and T2 (after 4 weeks of treatment) using clinical scales and 3d-Gait Analysis . Then, the patients treated with Sativex, were divided into 5 subgroups according to Numeric Rating Scale for spasticity (NRSs) and Berg Balance Score (BBS) response: NRSs responder[1] and non-[2]; BBS responders[3] and non-[4]; NRSs-BBS responders[5]. RESULTS: 32 pwMS (22 SG, 10 CG) were recruited. Significant improvements were found between T0 and T1 in SG compared to CG in a few clinical and kinematic parameters. Larger significant differences were found for NRSs and BBS responders' groups versus CG. Eventually, no significant differences were found comparing the results between T1 and T2, suggesting the persistence of the improvements emerged at T1. CONCLUSION: These results quantitatively demonstrated a short time effect of Nabiximols on balance and walking of pwMS, which is mantained after 4 weeks. Patients identified as responder by combination of NRSs and BBS showed the best efficacy. These findings may suggest how to early select the real responders in order to improve the adherence and cost-effectiveness of the therapy.