Claudia Condoluci

Motor dysfunctions in patients with Down Syndrome (DS) result in poor locomotion and an altered gait phenotype, characterized by compromised stability management and frequent bilateral asymmetries. Directing ground reaction forces to a point above the center of mass, referred to as the virtual pivot point (VPP), is one means of maintaining stability during walking. This cross-sectional observational study compared the dynamic gait function of 33 individuals with DS (mean age: 17.7 ± 6.4 years, 13 females) to a group of 36 healthy controls (mean age: 15.5 ± 6.1 years, 15 females), using the concept of the VPP. Results showed that the VPP was located more anteriorly in individuals with DS compared to healthy controls, with no differences in the variability (R²) or symmetry of VPP coordinates. This anterior VPP position is likely due to the larger hip moments observed in patients with DS during the propulsive phase of stance. High R² values in DS suggest that the VPP is strongly related to dynamic stability during walking.

Background: The primary aim of this study was to assess how different conformations of the foot in individuals with Down syndrome affected the CoP during walking, and the secondary aim was to evaluate the effect of an excess of mass in young adults and children with Down syndrome and flat foot. The greater investigation of these aspects will allow for more targeted rehabilitation treatments to improve a patient’s quality of life. Methods: The tests were carried out on 217 subjects with Down syndrome, 65 children and 152 young adults, and on 30 healthy individuals, 19 children and 11 young adults. All subjects underwent gait analysis, and the group with Down syndrome was also assessed with baropodometric tests to evaluate foot morphology. Results: The statistical analysis showed that within both the young adult and child groups, the CoP pattern in the anterior–posterior direction reflected a difficulty in proceeding in the walking direction compensated by a medio–lateral swing. The gait of children with Down syndrome was more impaired than that of young adults. In both young adults and children, a higher severity of impairment was found in overweight and obese female individuals. Conclusions: These results suggest that the sensory deficits and the development of hypotonic muscles and lax ligaments of the syndrome lead to morphological alterations of the foot that, combined with the physical characteristics of short stature and obesity, negatively impact the CoP pattern of people with Down syndrome during walking.

BACKGROUND: Parkinson's disease (PD) is a progressive neurological disorder characterized, among other symptoms, by a significant modified posture. Although a detailed assessment of postural abnormalities can be performed using quantitative movement analysis, the output of such procedure might be not suitable for a routine clinical use due to its intrinsic complexity. However, synthetic measures may facilitate the interpretation of kinematic data for physicians and thus make such tools fully exploitable in daily practice. AIM: According to these considerations, the aim of the present study is to propose a new summary index, the Postural Profile Score (PPS, together with its constituent variables: Postural Variable Scores [PVSs]), which can characterize the postural kinematic biomechanical profile of an individual; this approach was then applied to a cohort of individuals with PD. DESIGN: Controlled observational study. SETTING: Movement Analysis Laboratory of Hospital. POPULATION: Forty-five individuals with PD in mild to severe disability stage, of mean age 65.9 (SD 8.3) years and 21 healthy control age-matched (CG) were tested using an optoelectronic system during bipedal quiet standing. METHODS: Twelve joint angles of trunk and of lower limbs, considered representative of the whole-body posture according to Davis protocol, were acquired and the root mean square (RMS) difference between them and those of the unaffected participants (PVSs) were computed. Then, the PPS was calculated as a combination of the selected PVSs. The existence of possible differences between people with PD and controls for PPS and PVSs was assessed using MANOVA test. UPDRS III score was also considered in order to assess existence of correlation between synthetic indexes and Clinical scales values. RESULTS: Significant differences in PPS were detected between PD and CG (8.59 degrees vs. 6.11 degrees, P<0.001) and in some of the considered PVS (Trunk Sagittal, Trunk Frontal, Trunk Transversal, Hip flexion-extension, Hip abdo-adduction and Knee flexion-extension). Significant positive correlations were found between Clinical scales Vs trunk and ankle orientation. CONCLUSIONS: PPS could represent a reliable summary index of global postural abnormalities in people with PD, and in particular some PVSs appear more suitable to describe the deviation from a physiologic postural pattern. The results demonstrate that the posture in the patient with PD is modified compared to the control group. In particular, the trunk is the body district which mainly characterizes the alteration of the posture as documented by its PVSs values and their correlation with clinical evaluation scales. In conclusion, this study evidences the interest to measure the position of the trunk in order to characterize the postural kinematic position in individuals with PD. CLINICAL REHABILITAI1ON IMPACT: PPS could be a useful tool for the characterization of postural phenotype in subjects with Parkinson's disease and could provide indications for specific rehabilitation protocols.

Gait characteristics in Down Syndrome are documented in terms of discrete kinematic variables. However, such features are strictly interrelated and reflect neurological and developmental delays. A phenotypical, quantitative assessment of how multi-joint walking patterns are activated and controlled during gait would enhance the understanding of locomotor mechanisms in such patients. We adopted an analysis framework based on Principal Component Analysis: the gait kinematics of 221 patients aged 6-45 were expressed in terms of a reduced set of one-dimensional movement components. Their time course during the gait cycle was described by score vectors, here called principal positions; its second time derivative, called principal acceleration, characterized the activity of the neuromuscular controller on each component. Outcomes were compared to an age-matched group of 49 healthy individuals. After controlling for the effect of walking speed, we observed that the main alterations in gait patterns emerged in the fourth component which is mostly devoted to stability management (group differences, p<0.001). Rather, the main sagittal-plane locomotor patterns showed only subtle differences from the control group. Using statistical parametrical mapping, we found when (step-to-step transitions) and how (interrelated joints motion) the fourth movement deviated from normal: in particular, an excessive hip adduction and trunk inclination during the transition between single and double support phases. These findings match the neurological and sensorimotor trait of Down Syndrome and suggest the promotion of targeted rehabilitative interventions. Further, this study opens to the adoption of principal positions and principal accelerations to investigate the neuromuscular control of movement patterns during locomotion.

We evaluated the feasibility of a set of indexes based on ground reaction forces to discriminate between the degree of severity of spastic diplegia, identified via Gross Motor Function Classification System (GMFCS). A stepwise discriminant ordinal regression analysis performed on a sample of 58 children returned a subset of variables related to the ratio between braking and propulsive vertical forces and anteroposterior timings. Rather, parameters concerning bilateral symmetry were poorly discriminating. The relative simplicity of the selected indexes allows for their easy implementation on existing gait analysis applications for screening purposes.

BACKGROUND: In children with spastic cerebral palsy (CP), the treatment of equinus foot with Achilles tendon lengthening (ATL) surgery is associated with high incidence of overcorrection, which may result in crouch gait. AIM: We aimed to assess if gait pattern in preoperative time could be a predictor of the surgery outcome. DESIGN: Cross-sectional retrospective study. SETTING: Movement Analysis Lab of IRCCS San Raffaele Pisana Hospital in Rome (Italy). POPULATION : Eighteen children (mean age 9.6 +/- 4.7 years) with spastic diplegia CP who underwent bilateral ATL surgery to correct equinus foot were involved. METHODS: Participants underwent 3D gait analysis before and approximately 12 months after surgery. Primary measures were spatiotemporal, kinematic (summarized by Gait Variable Scores, GVSs) and kinetic parameters. The gait patterns for each leg was defined from kinematic data, using a quantitative classification: plantar flexor knee extension (PFKE) index. The CP group was split into true equinus and jump gait. RESULTS: The equinus foot was successfully corrected as demonstrated by the improvement of GVS ankle dorsi-plantarflexion. However, there was a high rate of overcorrection in the true equinus, characterized by increases in knee flexion-extension GVS (8.7 degrees pre vs. 16.7 degrees post P<0.05) and knee flexion angle at initial contact (5.2 degrees vs. 20.6 degrees P<0.05) and by a decrease in the maximum ankle power generated at push-off (1.49 vs. 0.83 W/kg P<0.05). CONCLUSIONS: Assessment of motor phenotype in preoperative time are good predictors of the results of ATL surgery. In children with true equinus gait, the increase of knee flexion subsequent to ATL is an early indicator that this technique will lead to crouch gait. These results show the influence of true equinus and jump gait patterns on the outcomes of the ATL. CLINICAL REHABILITATION IMPACT : Therefore, we propose that this approach could have clinical value to evaluate and prescribe rehabilitation in children with CP disease, proposing different solutions depending on motor phenotype.

Gait Initiation (GI) is a functional task that challenges the balance control requiring weight shift and a transition from standing to walking. Individuals with Down Syndrome (DS) walk with low velocity, prolonged stance and shorter steps beside an increased support base. However, no studies performed GI analysis on this population. The aim of this study is to quantitatively characterize the GI task in subjects with DS compared with a typically developed control group. Seventeen individuals with DS (17 to 40 years) and 19 healthy subjects (17 to 40 years) were enrolled in the study. Data were acquired using an optoelectronic motion capture system and force plates in order to measure the displacement and velocity of Center of Mass (CoM) and the trajectory of Center Of Pressure (CoP). All participants were asked to stand barefoot on the first force platform and received a verbal cue to begin walking for 6 gait initiation trials (three starting with each foot). The CoP duration, velocity, length and excursion were calculated during the anticipatory postural adjustments phases (APAs) and the locomotor (LOC) phase. For the analysis of the CoM, its displacements in antero-posterior (AP) and medio-lateral (ML) during the APAs and LOC phases. Statistical analysis was conducted to compare the two groups. Regarding CoP measures, when compared to control group, individuals with DS presented higher durations, lower velocities, longer lengths during the second APA and total phases, and shorter lengths during the first APA and LOC phases. The group with DS also presented longer CoP excursion during the second APA, whereas a shorter excursion was present during the first APA and LOC phases. The AP excursion in CoM is reduced in the participants with DS. Our results could be useful in the rehabilitation of individuals with DS as they suggest to reinforce exercise programs to improve balance in AP and ML directions, which is demonstrated to be impaired in these subjects.

Sex-specific medicine requires understanding of the specific therapeutic needs and patho-physiology of men and women. In these terms, we investigated sex-related differences in the gait kinematics of patients with Down syndrome. Retrospective observational cohort study. A sample of 230 patients (103 females) aged 7-50 years underwent a standard gait-analysis test from 2000 to 2015. Spatiotemporal gait parameters and synthetic indexes were computed as Gait Profile Score (GPS) and pelvis/lower limbs as Gait Variable Scores. Although speed, normalized step width, %stance and %swing were similar, in female patients step length was shorter and GPS was higher than in male patients, with no significant effect of age, speed and body mass index. Sex-specific features were found at the pelvis, hip and knee level (sagittal plane), and at the ankle level (transverse plane). Overall, in people with Down syndrome, the gait function of females tends to be more impaired than in males, with the exception of foot progression. Therapists should consider these differences when evaluating the severity of gait impairment and designing rehabilitation strategies.

BACKGROUND: The shuffling steps pattern is a typical feature of gait in patients affected by Parkinson's disease (PD), which progressively reduces their quality of life, being related to the risk of falls in this population. Recently, Automated Mechanical Peripheral Stimulation (AMPS) was presented as an integrative rehabilitative treatment based on peripheral stimulation able to improve the gait spatiotemporal parameters in PD patients. AIM: The aim of this study was to evaluate the effects of AMPS on shuffling steps pattern by analyzing the kinematic and spatio-temporal gait parameters. DESIGN: Double blind randomized longitudinal study. SETTING: Outpatients. POPULATION: PD patients. METIIODS: In this double blind randomized longitudinal study, 14 patients with PD were treated with effective-AMPS (AMPS group), while 14 PD patients were treated with placebo-AMPS (SHAM group); 32 healthy subjects were deemed the control group (CG). A dedicated medical device (Gondola (TM) Medical Technologies, Stabio, Switzerland) was used to deliver both stimulations. Each treatment session lasted about 15 minutes, including preparation (approx. 10 to 13 minutes) and stimulation (approx. 2 minutes). All PD patients were given six AMPS/SHAM treatments sessions, twice a week, delivered during the off-levodopa phase, having withdrawn from dopaminergic medication overnight. We evaluated spatio-temporal and kinematic variables of gait with quantitative 3D-gait analysis as follows: before and after the first intervention (acute phase), then after the sixth session (long term phase). RESULTS: We detected differences in all gait variables immediately after the first session of AMPS treatment and again after the sixth stimulation session. CONCLUSIONS: AMPS treatment changes the shuffling steps pattern that is typical of PD subjects, increasing the ROM of hip, knee and ankle joints during the gait cycle. CLINICAL REHABILITATION IMPACT: This data presents further evidence that a rehabilitative approach based on the AMPS treatment can induce improvements in the gait pattern of patients affected by PD.