Cyclogram-based evaluation of inter-limb gait symmetry in Prader-Willi Syndrome.

BACKGROUND: Prader-Willi syndrome (PWS) is characterized by a complex clinical condition, whose typical features lead to impaired motor and functional skills. To date, limited data is available as regards symmetry of gait in PWS. RESEARCH QUESTION: The aim of this study was to characterize lower-limb asymmetry during gait in a group of Prader-Willi Syndrome (PWS) individuals by using the synchronized cyclograms and to compare it with those of two different control groups, a normal-weight group and an obese group. METHODS: A total of 18 PWS, 30 normal weight (NW) and 28 obese individuals (OG) matched for age, sex and height were assessed via 3D gait analysis. Gait spatio-temporal parameters were computed together with angle-angle diagrams, characterized in terms of their geometric features (i.e. area, orientation, and trend symmetry index). RESULTS: Individuals with PWS exhibit reduced speed, stride length and cadence and increased duration of both stance and double support phase than the other groups. OG was characterized by the same pattern when compared to NW. With respect to inter-limb symmetry, individuals with PWS exhibited significantly larger cyclogram areas at hip joint with respect to the other two groups (203.32 degrees2 vs. 130.73 degrees2 vs. 111.59 degrees2) and significantly higher orientation angle (4.17° vs. 2.11° vs. 1.22°) and Trend Symmetry (3.72 vs. 2.02 vs. 1.21) with respect to the other two groups at knee joint; no differences were found at ankle joint. Both individuals with PWS and those of OG exhibited reduced ROM at knee and ankle joints with respect with normal weight, but no statistically significant differences were observed between PWS and OG. SIGNIFICANCE: The obtained results may provide novel and useful insights to understand better the impairments in motor control associated with this pathological state, supporting clinics in the identification of the best rehabilitation program for this rare pathological state, aimed to improve stability and motor control.

Segmental Mandibulectomy and Mandibular Reconstruction with Fibula-Free Flap Using a 3D Template.

INTRODUCTION: The present study evaluates the influence of virtual surgical planning with a preoperative 3D resin model on aesthetic and functional outcomes in patients treated by segmental mandibulectomy and reconstruction with fibula-free flap for oral cancer. METHODS: All consecutive patients who underwent segmental mandibulectomy and mandibular reconstruction with a fibula-free flap using a 3D template at our department from January 2021 to January 2023 were included in the study. "Patients control" were patients treated by reconstruction with a fibula-free flap without using a 3D template. Three-dimensional modeling was performed by converting from preoperative computed tomography to a stereolithography format to obtain the resin 3D models. Qualitative analysis of anatomical and aesthetic results consisted of the evaluation of the patients' aesthetic and functional satisfaction and the symmetry of the mandibular contour observed at clinical examination. Quantitative analysis was based on the assessment of the accuracy and precision of the reconstruction by comparing preoperative and postoperative computed tomograms as objective indicators. RESULTS: Seven patients (five males and two females, mean age of 65.1 years) were included in the study. All patients showed a symmetric mandibular contour based on the clinical examination. After recovery, six patients (85.7%) considered themselves aesthetically satisfied. The quantitative analysis (assessed in six/seven patients) showed that the mean difference between preoperative and postoperative intercondylar distance, intergonial angle distance, anteroposterior dimension, and gonial angle improved in the 3D template-assisted group. CONCLUSION: The 3D-printed template for mandibular reconstruction with microvascular fibula-free flap can improve aesthetic outcomes in comparison with standard approaches.

Cybersickness in People with Multiple Sclerosis Exposed to Immersive Virtual Reality.

Together with the wide range of possible benefits for the rehabilitation/training of people with multiple sclerosis (pwMS) and other neurologic conditions, exposure to immersive virtual reality (VR) has often been associated with unpleasant symptoms, such as transient dizziness, headache, nausea, disorientation and impaired postural control (i.e., cybersickness). Since these symptoms can significantly impact the safety and tolerability of the treatment, it appears important to correctly estimate their presence and magnitude. Given the existing data scarcity, this study aims to assess the existence and severity of possible adverse effects associated with exposure to immersive VR in a cohort of pwMS using both objective measurements of postural control effectiveness and subjective evaluations of perceived symptoms. To this aim, postural sway under upright quiet posture (in the presence and absence of visual input) of 56 pwMS with an Expanded Disability Status Scale score (EDSS) in the range of 0-6.5 (mean EDSS 2.3) and 33 unaffected individuals was measured before and after a 10-min immersive VR session and at 10 min follow-up on the basis of center of pressure (COP) trajectories. The severity of cybersickness symptoms associated with VR exposure was also self-rated by the participants using the Italian version of the Simulator Sickness Questionnaire (SSQ). Temporary impairments of postural control in terms of significantly increased sway area were observed after the VR session only in pwMS with mild-moderate disability (i.e., EDSS in the range of 2.5-6.5) in the presence of visual input. No changes were observed in pwMS with low disability (EDSS 0-2) and unaffected individuals. In contrast, when the visual input was removed, there was a decrease in sway area (pwMS with mild-moderate disability) and COP path length relating to the use of VR (pwMS with mild-moderate disability and unaffected individuals), thus suggesting a sort of "balance training effect". Even in this case, the baseline values were restored at follow-up. All participants, regardless of their status, experienced significant post-VR side effects, especially in terms of blurred vision and nausea. Taken together, the findings of the present study suggest that a short immersive VR session negatively (eyes open) and positively (eyes closed) impacts the postural control of pwMS and causes significant disorientation. However, such effects are of limited duration. While it is reasonable to state that immersive VR is sufficiently safe and tolerable to not be contraindicated in the rehabilitation/training of pwMS, in order to reduce possible negative effects and maximize the efficacy, safety and comfort of the treatment, it appears necessary to develop specific guidelines that consider important factors like individual susceptibility, maximum exposure time according to the specific features of the simulation, posture to adopt and protocols to assess objective and perceived effects on participants.

Characterization of upper limb use in health care workers during regular shifts: A quantitative approach based on wrist-worn accelerometers.

Despite the high prevalence of upper limb (UL) work-related musculoskeletal disorders (WRMSD) among health care workers (HCWs), little is known about their relationship with exposure to biomechanical risk factors. This study aimed to assess UL activity features under actual working conditions using two wrist-worn accelerometers. Accelerometric data were processed to obtain duration, intensity, and asymmetry of UL use in 32 HCWs during the execution of commonly performed tasks (e.g., patient hygiene, transfer, and meal distribution) within a regular shift. The results show that such tasks are characterized by significantly different patterns of UL use, in particular, higher intensities and larger asymmetries were observed respectively for patient hygiene and meal distribution. The proposed approach appears, thus, suitable to discriminate tasks characterized by different UL motion patterns. Future studies could benefit from the integration of such measures with self-reported workers' perception to elucidate the relationship between dynamic UL movements and WRMSD.

Motor and cognitive skills implicated in the Motor Observation Questionnaire for Teachers (MOQ-T): A multidisciplinary approach.

This study was designed to determine the relationship between an observational measure of motor skills for teachers (i.e., MOQ-T), age, and some objectively assessed cognitive and motor indices. Two further goals were to examine which motor and cognitive factors predicted MOQ-T scores and to explore whether pupils with very low motor skills identified through MOQ-T also exhibited lower scores on objectively assessed motor and visuo-spatial tasks. A sample of 156 pupils aged 8.4 years-11.3 years and attending Italian primary school completed a battery of tests assessing writing speed, visuo-spatial abstract reasoning, fluency, and static balance abilities objectively assessed by measuring postural sway. Small to medium associations were found between MOQ-T scores and age, motor, and cognitive parameters, respectively. Moreover, approximately 26% of the variance in MOQ-T was predicted by sway area in the eyes-open condition, visuo-spatial fluency, and writing speed. Finally, pupils at risk of developmental coordination disorder exhibited poorer writing speed, and motor and higher-order visuo-spatial deficits. In conclusion, the synergistic use of objective measures of motor and cognitive functioning and observational screening questionnaires such as MOQ-T should be encouraged at school to identify pupils at risk of developmental coordination disorder.

Smoothness of Gait in Overweight (But Not Obese) Children Aged 6-10.

Excessive body mass represents a serious threat to the optimal psychophysical development of children, and it is known to be able to significantly affect their locomotor capabilities, making them more prone to the development of musculoskeletal disorders. However, despite the relevant number of existing studies, a clear gait pattern of overweight children has not been defined yet, particularly in the case of a mass excess that is relatively small (i.e., in those not obese). In the present study, we employed a wearable inertial measurement unit placed on the low back to derive spatio-temporal parameters and quantify the smoothness of gait (by means of harmonic ratio) from trunk accelerations acquired during gait trials carried out by 108 children aged 6-10 (46% males), stratified into two groups according to their body mass index (normal weight, n = 69 and overweight, n = 39). The results show that while gait speed, stride length, cadence and double support duration were found to be almost identical in the two groups, significant differences were observed in terms of harmonic ratio. In particular, overweight children exhibited a reduced harmonic ratio in the antero-posterior direction and higher harmonic ratio in the medio-lateral direction. While the significantly lower harmonic ratio in the antero-posterior direction is likely to be indicative of a loss of smoothness in the walking direction, probably due to a combination of factors associated with the altered movement biomechanics, the higher harmonic ratio in the medio-lateral direction might be associated with specific strategies adopted to increase lateral stability. Although further studies are necessary to elucidate the specific mechanisms that influence the smoothness of gait, it is noteworthy that harmonic ratios appear sensitive even to subtle change in locomotor control in overweight children characterized by apparently regular spatio-temporal parameters of gait and might be employed to assess the effectiveness of interventions designed to improve mobility functions.

Executive Functions and Mood States in Athletes Performing Exercise Under Hypoxia.

Hypoxia can impair cognitive performance, whereas exercise can enhance it. The effects of hypoxia on cognitive performance during exercise appear to be moderated by exercise duration and intensity and by severity and duration of hypoxia and cognitive task. In normal individuals, exercise under hypoxia can evoke adverse post-exercise mood states, such as tension and fatigue. However, little is known about the effects of hypoxia during exercise in trained athletes. The purpose of this study was to investigate how hypoxia affected executive functions and mood states, assessed, respectively, during and post-exercise and to explore the role of motivation moderators, such as inhibition and activation systems (BIS-BAS). Two different sessions of exercise in normoxia and hypoxia (FiO2 13%), each lasting 18 min, were randomly assigned in a counterbalanced order and administered to seventeen male athletes. During exercise bouts, participants performed a mental task (BST) aimed to produce cognitive interference and suppression. Reaction times and accuracy of responses were recorded. After 5 min, all participants completed two questionnaires assessing mood states (ITAMS) and incidence of symptoms potentially related to hypoxia (AMS-C). The results show that hypoxia impairs cognitive performance in terms of slower reaction times, but a high BAS attenuates this effect. Participants with high BAS show an equivalent cognitive performance under hypoxia and normoxia conditions. No effects were found on mood states. Further research is required to investigate the role of BAS, cognitive abilities, and mood states in prolonged hypoxic conditions.

A Study on Lower Limb Asymmetries in Parkinson's Disease during Gait Assessed through Kinematic-Derived Parameters.

Unilaterality of motor symptoms is a distinctive feature of Parkinson's Disease (PD) and represents an important co-factor involved in motor deficits and limitations of functional abilities including postural instability and asymmetrical gait. In recent times, an increasing number of studies focused on the characterization of such alterations, which have been associated with increased metabolic cost and risk of falls and may severely compromise their quality of life. Although a large number of studies investigated the gait alterations in people with PD (pwPD), few focused on kinematic parameters and even less investigated interlimb asymmetry under a kinematic point of view. This retrospective study aimed to characterize such aspects in a cohort of 61 pwPD (aged 68.9 ± 9.3 years) and 47 unaffected individuals age- and sex-matched (66.0 ± 8.3 years), by means of computerized 3D gait analysis performed using an optical motion-capture system. The angular trends at hip, knee and ankle joints of pwPD during the gait cycle were extracted and compared with those of unaffected individuals on a point-by-point basis. Interlimb asymmetry was assessed using angle-angle diagrams (cyclograms); in particular, we analyzed area, orientation, trend symmetry and range offset. The results showed that pwPD are characterized by a modified gait pattern particularly at the terminal stance/early swing phase of the gait cycle. Significant alterations of interlimb coordination were detected at the ankle joint (cyclogram orientation and trend symmetry) and at the hip joint (range offset). Such findings might be useful in clinical routine to characterize asymmetry during gait and thus support physicians in the early diagnosis and in the evaluation of the disease progression.

Inter-joint coordination during gait in people with multiple sclerosis: A focus on the effect of disability.

BACKGROUND: Walking difficulties, which are widespread among people with MS (pwMS), represent one of the major factors contributing to physical disability and, as such, may greatly affect an individual's independence and quality of life. In this context, the study of lower limb kinematics may provide an important contribution to unveiling the underlying mechanisms of walking dysfunctions in MS. However, limited information about the inter-joint coordination during gait-the functional relationship between joint pairs during the whole gait cycle-is available. METHODS: We retrospectively analyzed the gait patterns of 104 pwMS (56 women, 48 men, mean age 46.3, average Expanded Disability Status Scale score 3.5) and 84 unaffected individuals age-and-sex-matched, who underwent 3D computerized gait analysis carried out using an optical motion capture system. PwMS were also stratified into two groups according to their level of disability. Those with EDSS ≤ 3.5 (n = 62) formed the "low-mild disability" group, while those with EDSS > 3.5 (n = 42) were assigned to the "moderate-severe disability" group. The raw data were processed to calculate the main spatio-temporal parameters and the kinematics in the sagittal plane at the hip, knee, and ankle joints. At each point of the gait cycle, the angular values were employed to build angle-angle diagrams (cyclograms) for the hip-knee and the knee-ankle joint couples. Inter-joint coordination was quantified using geometric features of the cyclograms (i.e., area, perimeter, and dimensionless ratio) and compared between groups. For pwMS only, we also explored possible relationships between cyclograms parameters, disability level, and spatio-temporal parameters of gait. RESULTS: PwMS exhibit a well-known gait pattern characterized by reduced speed, stride length, increased step width, and double support phase duration. Their inter-joint coordination was found altered at both hip-knee and knee-ankle joint couples, as indicated by the significantly reduced cyclogram area and perimeter with respect to unaffected individuals. However, the detailed analysis of the angle-angle diagram trajectories showed some differences associated with the level of disability. In particular, pwMS with mild-low disability exhibit cyclograms partly superposed with those of unaffected individuals in the first half of the stance phase (hip-knee couple) and the second half of the swing phase (knee-ankle couple), while in those with a moderate-severe disability, the differences are substantially extended to the whole gait cycle. Significant moderate to large correlations were also observed between cyclogram area and perimeter, EDSS score, and spatio-temporal parameters of gait. CONCLUSION: The study of inter-joint coordination during gait in pwMS represents a useful source of information about the way lower limb joints interact, thus potentially expanding the knowledge of the mechanisms underlying walking dysfunctions associated with the disease. From a clinical perspective, the availability of reference data for the co-variation of hip-knee and knee-ankle joint angles during gait can effectively support both the characterization of the progression of the disease and the assessment of the effectiveness of rehabilitative treatments.

Characterization of hand forces exerted during non-powered hospital bed pushing and pulling tasks.

Accurate assessment of biomechanical risk associated with pushing/pulling tasks represents a challenging issue, especially in the health system where personnel are often required to maneuver beds and carts. Most studies in this field have been carried out in the laboratory, while few data have been collected under actual working conditions. This study aims to characterize the forces exerted during non-powered hospital bed maneuvering. Twenty participants were required to move a bed (equipped with a customized handlebar to measure exerted forces) along an actual hospital path including straight, turn and maneuver phases. The results show that higher forces are associated with the initial phase (peak and mean values 222 and 68 N) while the straight, turn and maneuvering phases required similar (lower) efforts. The combined effect of left, right and transversal forces suggests that the trunk of the operator might experience axial rotation, thus calling for further investigations of this aspect.

Trunk sway changes in professional bus drivers during actual shifts on long-distance routes.

Although professional bus drivers are required to perform their task while adopting a prolonged constrained sitting posture, existence of possible effects in terms of postural strategies has been scarcely investigated under actual working conditions. This study aimed to characterise modifications of trunk sway in 14 professional bus drivers during regular shifts performed on non-urban routes using a pressure-sensitive mat placed on the seat. Centre-of-pressure (COP) time series were extracted from body-seat pressure data to calculate sway parameters (i.e. sway area, COP path length, COP displacements and velocities). Results show generalised increase in trunk sway as driving progresses, which becomes statistically significant after approximately 70-100 minutes of continuous driving. This may indicate the adoption of specific strategies to cope with discomfort onset or a fatigue-induced alteration of postural features. Trunk sway monitoring of bus drivers may be useful in detecting postural behaviours potentially associated with deteriorating performance and discomfort onset. Practitioner summary: Professional bus drivers operate in sitting position for prolonged time. Such constrained posture may induce discomfort and fatigue. We investigated trunk sway during actual shifts using pressure-sensitive mats. Significant increase of sway was detected after 70 min of continuous driving. Body-seat pressure data could be used as discomfort and fatigue markers. Abbreviations: ANOVA-RM: analysis of variance with repeated measures; AP: antero-posterior; COP: center of pressure; EC: ellipse's centroid; ML: medio-lateral; SA: sway area; SP: sway path.

Kinematics Adaptation and Inter-Limb Symmetry during Gait in Obese Adults.

The main purpose of this study is to characterize lower limb joint kinematics during gait in obese individuals by analyzing inter-limb symmetry and angular trends of lower limb joints during walking. To this purpose, 26 obese individuals (mean age 28.5 years) and 26 normal-weight age- and sex-matched were tested using 3D gait analysis. Raw kinematic data were processed to derive joint-specific angle trends and angle-angle diagrams (synchronized cyclograms) which were characterized in terms of area, orientation and trend symmetry parameters. The results show that obese individuals exhibit a kinematic pattern which significantly differs from those of normal weight especially in the stance phase. In terms of inter-limb symmetry, higher values were found in obese individuals for all the considered parameters, even though the statistical significance was detected only in the case of trend symmetry index at ankle joint. The described alterations of gait kinematics in the obese individuals and especially the results on gait asymmetry are important, because the cyclic uneven movement repeated for hours daily can involve asymmetrical spine loading and cause lumbar pain and could be dangerous for overweight individuals.

Use of wrist-worn accelerometers to quantify bilateral upper limb activity and asymmetry under free-living conditions in people with multiple sclerosis.

BACKGROUND: Although upper limb (UL) dysfunctions are quite common among people with Multiple Sclerosis (pwMS), there is a scarcity of information about actual UL usage under free-living conditions. The aim of the present study is to quantitatively assess 'real-world' activity time, intensity and possible asymmetry of use among dominant and non-dominant ULs in pwMS. METHODS: Twenty-eight pwMS (20 women, 8 men, average EDSS 4.3) and 28 age- and sex-matched unaffected individuals were required to wear a tri-axial accelerometer on each wrist 24h/day for 2 weekdays. Raw accelerations were processed to calculate parameters associated with time and intensity of use of UL both when engaged in uni- or bilateral activities. RESULTS: During the 2-day monitoring period, pwMS were characterized by significantly lower overall activity, they used their dominant limb for a significantly longer time and, while performing bilateral activities, their dominant limb expressed movements of superior intensity in a proportion higher than what was observed in unaffected individuals. CONCLUSION: The instrumental monitoring of UL activity with two wrist-worn sensors may represent an effective tool for assessing the contribution of each limb to uni- and bilateral movements. Such data can be employed to monitor the progression of UL dysfunctions and the effectiveness of pharmacologic and rehabilitative treatments.

Lower Limb Kinematics in Individuals with Hip Osteoarthritis during Gait: A Focus on Adaptative Strategies and Interlimb Symmetry.

Among the functional limitations associated with hip osteoarthritis (OA), the alteration of gait capabilities represents one of the most invalidating as it may seriously compromise the quality of life of the affected individual. The use of quantitative techniques for human movement analysis has been found valuable in providing accurate and objective measures of kinematics and kinetics of gait in individuals with hip OA, but few studies have reported in-depth analyses of lower limb joint kinematics during gait and, in particular, there is a scarcity of data on interlimb symmetry. Such aspects were investigated in the present study which tested 11 individuals with hip OA (mean age 68.3 years) and 11 healthy controls age- and sex-matched, using 3D computerized gait analysis to perform point-by-point comparisons of the joint angle trends of hip, knee, and ankle. Angle-angle diagrams (cyclograms) were also built to compute several parameters (i.e., cyclogram area and orientation and Trend Symmetry) from which to assess the degree of interlimb symmetry. The results show that individuals with hip OA exhibit peculiar gait patterns characterized by severe modifications of the physiologic trend at hip level even in the unaffected limb (especially during the stance phase), as well as minor (although significant) alterations at knee and ankle level. The symmetry analysis also revealed that the effect of the disease in terms of interlimb coordination is present at knee joint as well as hip, while the ankle joint appears relatively preserved from specific negative effects from this point of view. The availability of data on such kinematic adaptations may be useful in supporting the design of specific rehabilitative strategies during both preoperative and postoperative periods.

Functional Electrical Stimulation for Foot Drop in Post-Stroke People: Quantitative Effects on Step-to-Step Symmetry of Gait Using a Wearable Inertial Sensor.

The main purpose of the present study was to assess the effects of foot drop stimulators (FDS) in individuals with stroke by means of spatio-temporal and step-to-step symmetry, harmonic ratio (HR), parameters obtained from trunk accelerations acquired using a wearable inertial sensor. Thirty-two patients (age: 56.84 ± 9.10 years; 68.8% male) underwent an instrumental gait analysis, performed using a wearable inertial sensor before and a day after the 10-session treatment (PRE and POST sessions). The treatment consisted of 10 sessions of 20 min of walking on a treadmill while using the FDS device. The spatio-temporal parameters and the HR in the anteroposterior (AP), vertical (V), and mediolateral (ML) directions were computed from trunk acceleration data. The results showed that time had a significant effect on the spatio-temporal parameters; in particular, a significant increase in gait speed was detected. Regarding the HRs, the HR in the ML direction was found to have significantly increased (+20%), while those in the AP and V directions decreased (approximately 13%). Even if further studies are necessary, from these results, the HR seems to provide additional information on gait patterns with respect to the traditional spatio-temporal parameters, advancing the assessment of the effects of FDS devices in stroke patients.

Smoothness of Gait in Healthy and Cognitively Impaired Individuals: A Study on Italian Elderly Using Wearable Inertial Sensor.

The main purpose of the present study was to compare the smoothness of gait in older adults with and without cognitive impairments, using the harmonic ratio (HR), a metric derived from trunk accelerations. Ninety older adults aged over 65 (age: 78.9 ± 4.8 years; 62% female) underwent instrumental gait analysis, performed using a wearable inertial sensor and cognitive assessment with the Mini Mental State Examination (MMSE) and Addenbrooke's Cognitive Examination Revised (ACE-R). They were stratified into three groups based on their MMSE performance: healthy controls (HC), early and advanced cognitive decline (ECD, ACD). The spatio-temporal and smoothness of gait parameters, the latter expressed through HR in anteroposterior (AP), vertical (V) and mediolateral (ML) directions, were derived from trunk acceleration data. The existence of a relationship between gait parameters and degree of cognitive impairment was also explored. The results show that individuals with ECD and ACD exhibited significantly slower speed and shorter stride length, as well as reduced values of HR in the AP and V directions compared to HC, while no significant differences were found between ECD and ACD in any of the investigated parameters. Gait speed, stride length and HR in all directions were found to be moderately correlated with both MMSE and ACE-R scores. Such findings suggest that, in addition to the known changes in gait speed and stride length, important reductions in smoothness of gait are likely to occur in older adults, owing to early/prodromal stages of cognitive impairment. Given the peculiar nature of these metrics, which refers to overall body stability during gait, the calculation of HR may result in being useful in improving the characterization of gait patterns in older adults with cognitive impairments.

Changes in symmetry during gait in adults with Prader-Willi syndrome.

Most studies on locomotion of individuals with the Prader-Willi Syndrome (PWS) have been performed in a laboratory setting using quantitative motion analysis. Recently, wireless inertial sensors have been successfully employed for gait analysis in different pathological states with the advantages of reproducing a testing condition very close to those encountered in daily living. Using such devices, it is possible not only to characterize the conventional spatio-temporal parameters, but also extract information on further less conventional metrics, such as the harmonic ratio (HR), a measure of step-to-step symmetry based on trunk acceleration processing. In the present study, this technique was used to quantify gait parameters during level walking in 20 adults with PWS who were compared to 20 unaffected individuals. While no differences between the two groups were found in terms of spatio-temporal parameters, individuals with PWS exhibited significantly reduced values of HR in the antero-posterior and vertical directions. Such results, which indicate a poorer gait symmetry in PWS, suggest that upper body accelerations, as well as HR, provide novel information on gait in people with PWS that could not be extracted from spatio-temporal parameters only.

Age-Related Changes in Smoothness of Gait of Healthy Children and Early Adolescents.

In this study, we acquired and processed trunk accelerations during level walking in 85 children aged 8-13 years to calculate spatio-temporal parameters and Harmonic Ratio (HR), which is a metrics representative of gait smoothness and step-to-step symmetry. The results show that while spatio-temporal parameters remain unchanged once normalized considering individuals' anthropometry, significantly higher values of HR for both the antero-posterior and vertical directions were found in participants aged 12-13 with respect to those of 8-9. This indicates an improvement of gait symmetry, which suggests that the gait maturation process is still ongoing for the age ranges tested here.

Symmetry of Gait in Underweight, Normal and Overweight Children and Adolescents.

Abnormal excess or lack of body mass can influence gait patterns, but in some cases such differences are subtle and not easy to detect, even with quantitative techniques for movement analysis. In these situations, the study of trunk accelerations may represent an effective way to detecting gait anomalies in terms of symmetry through the calculation of Harmonic Ratio (HR), a parameter obtained by processing trunk accelerations in the frequency domain. In the present study we used this technique to assess the existence of differences in HR during gait in a cohort of 75 healthy children and early adolescents (aged 7-14 years) stratified into 3 equally-sized age and gender-matched groups (Underweight: UW; Normal Weight: NW; Overweight: OW). The accelerometric signal, acquired using a single wearable inertial sensor, was processed to calculate stride length, speed, cadence and HR in antero-posterior, vertical and medio-lateral directions. No differences in spatio-temporal parameters were found among groups, while the HR in the medio-lateral direction was found significantly lower in UW children, while OW exhibited the highest values. On the basis of the results obtained, HR appears capable of discriminating gait symmetry in children with different body mass even when conventional gait parameters are unchanged.

Dynamic postural stability, is associated with competitive level, in youth league soccer players.

OBJECTIVES: To assess the effect of competitive level on dynamic postural stability in young elite and sub-elite soccer players. DESIGN: Cross-sectional study. SETTING: Laboratory. PARTICIPANTS: Fifty-four male soccer players of Under 16 and Under 17 categories (mean age 15.9 ±â€¯0.6), divided into two groups who regularly compete at national (n = 28) and regional (n = 26) levels. MAIN OUTCOME MEASURES: Dynamic Postural Stability Index (DPSI) and vertical Time to Stabilization (vTTS) for a forward-jump landing. Static postural sway was calculated on the basis of center-of-pressure trajectories for a 20 s one-legged stance. RESULTS: Players at national level exhibit better dynamic postural control than those at regional level, as indicated by the significantly lower DPSI (0.327 vs. 0.373, p < 0.001) and vTTS (0.887 vs. 1.158 s, p = 0.003). In contrast, no differences between groups were found in any of the postural sway parameters for the static test. CONCLUSIONS: Young soccer players at national level are characterized by better balance performance in terms of faster and more efficient stabilization after a forward jump, while one-leg static standing tests appear not challenging enough to reveal differences in balance abilities associated with the combination of superior technical and physical features.