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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 degrees 2 vs. 130.73 degrees 2 vs. 111.59 degrees 2 ) 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., Competing Interests: Declaration of Competing Interest we are undersigned authors of the manuscript as Original Research entitled “Cyclogram-based Evaluation of Inter-limb Gait Symmetry in Prader-Willi Syndrome” by Massimiliano Pau, Serena Cerfoglio, Paolo Capodaglio, Flavia Marrone, Graziano Grugni, Micaela Porta, Bruno Leban, Manuela Galli and Veronica Cimolin, submitted to Gait & Posture for publication hereby attest and affirm that the material within has not been and will not be submitted for publication elsewhere and that they were fully involved in the study and preparation of the manuscript. All authors haven’t any conflicts of interest and any financial interest., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Purpose: Individuals with Prader-Willi syndrome (PWS) exhibit reduced lean body mass and increased fat-lean mass ratio when compared with individuals of normal weight and obese ones. Thus, research on the association of functional limitations during gait and body composition may be of great importance from a rehabilitative viewpoint. In particular, the aim of this study was to compare the gait profile of persons with PWS to that of unaffected individuals and to see if a relationship exists between gait profile and body composition in individuals with PWS., Methods: Eighteen individuals with PWS and 20 unaffected individuals (Healthy Group: HG) were assessed. Their gait pattern was quantified with 3D-Gait Analysis (3D-GA). Overall body weight, lean and fat masses were measured by dual-energy X-ray absorptiometry., Results: Individuals with PWS were found to be characterized by a significantly different (p < 0.05) gait pattern with respect to healthy controls in terms of both kinematic and kinetic parameters. No correlations were found between kinematic parameters and overall mass and lean/fat mass, while some parameters associated with ground reaction force were found to be significantly correlated with overall mass, lean mass and fat mass. Significant regression models were obtained, including impact and propulsive force and loading rate., Conclusion: Our data suggest that in individuals with PWS, gait is influenced by the overall and lean body mass. Thus, therapeutic strategies should target both weight reduction and lean mass increase to optimize gait, minimize articular stress, and reduce the risk of repetitive strain on the lower limbs., Level of Evidence: Level III: Case-control analytic study.

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.

Background: Gait Initiation (GI) is a functional task representing one of the first voluntary destabilizing behaviours observed in the development of a locomotor pattern as the whole body centre of mass transitions from a large to a small base of support. Conversely, Gait Termination (GT) consists in the transition from walking to standing which, in everyday life, is a very common movement. Compared to normal walking, it requires higher control of postural stability. For a safe GT, the forward movement of the body has to be slowed down to achieve a stable upright position. Stability requirements have to be fulfilled for safe GT. In individuals with Prader-Willi syndrome (PWS), excessive body weight negatively affects the movement, such as walking and posture, but there are no experimental studies about GI and GT in these individuals. The aim of this study was to quantitatively characterise the strategy of patients with PWS during GI and GT using parameters obtained by the Center of Pressure (CoP) track., Methods: Twelve patients with PWS, 20 obese (OG) and 19 healthy individuals (HG) were tested using a force platform during the GI and GT tasks. CoP plots were divided into different phases, and duration, length and velocity of the CoP trace in these phases were calculated and compared for each task., Results: As for GI, the results showed a significant reduction of the task duration and lower velocity and CoP length parameters in PWS, compared to OG and HG. In PWS, those parameters were reduced to a higher degree with respect to the OG. During GT, longer durations, similar to OG, were observed in PWS than HG. Velocity is reduced when compared to OG and HG, especially in medio-lateral direction and in the terminal part of GT., Conclusions: From these data, GI appears to be a demanding task in most of its sub-phases for PWS individuals, while GT seems to require caution only towards the end of the task. Breaking the cycle of gait into the phases of GI and GT and implementing specific exercises focusing on weight transfer and foot clearance during the transition phase from the steady condition to gait will possibly improve the effectiveness of rehabilitation and fall and injury prevention.

The suitability of new dynamic system analysis was investigated to compare postural control in Prader-Willi syndrome (PWS) and Down syndrome (DS) patients. Time-domain, frequency-domain parameters and fractal dimension (FD) of centre of pressure (CoP) were computed in maintaining normal standing on a force platform in 20 DS and 13 PWS patients, compared to 26 obese (obese control group, OCG) and 20 healthy individuals (healthy control group, HCG). DS and PWS showed greater displacements along both directions and longer sway path (SP) parameter than HCG and OCG, with statistical differences between PWS and DS for anteroposterior displacement and SP. DS used higher frequency strategy when compared to PWS, OCG and HCG. Both DS and PWS were characterised by greater values of FD than OCG and HCG, with higher values in DS. The analyses in frequency domain and of the dynamic nature of CoP suggest that DS patients are characterised by a more complex and irregular signal than PWS patients.

This study aimed to quantify and compare the gait pattern in Ehlers-Danlos (EDS) and Prader-Willi syndrome (PWS) patients to provide data for developing evidence-based rehabilitation strategies. Twenty EDS and 19 PWS adult patients were evaluated with an optoelectronic system and force platforms for measuring kinematic and kinetic parameters during walking. The results were compared with those obtained in a group of 20 normal-weight controls (CG). The results showed that PWS patients walked with longer stance duration and reduced velocity than EDS, close to CG. Both EDS and PWS showed reduced anterior step length than CG. EDS kinematics evidenced a physiological position at proximal joints (pelvis and hip joint) while some deficits were displayed at knee (reduced flexion in swing phase) and ankle level (plantar flexed position in stance and reduced dorsal flexion in swing). PWS showed a forward tilted pelvis in the sagittal plane, excessive hip flexion during the whole gait cycle and an increased hip movement in the frontal plane. Their knees were flexed at initial contact with reduced range of motion while ankle joints showed a plantar flexed position during stance. No differences were found in terms of ankle kinetics and joint stiffness. Our data showed that EDS and PWS patients were characterized by a different gait strategy: PWS showed functional limitations at every level of the lower limb joints, whereas in EDS limitations, greater than PWS, were reported mainly at the distal joints. PWS patients should be encouraged to walk for its positive impact on muscle mass and strength and energy balance. For EDS patients the rehabilitation program should be focused on ankle strategy improvement., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

The aim of this study was to quantify the role of visual contribution in patients with Prader-Willi syndrome (PWS) on balance maintenance using a force platform. We enrolled 14 individuals with PWS free from conditions associated with impaired balance, 44 obese (OG) and 20 healthy controls (CG). Postural sway was measured for 60s while standing on a force platform (Kistler, CH; acquisition frequency: 500 Hz) integrated with a video system. Patients maintained an upright standing position with Open Eyes (OE) and then with Closed Eyes (CE). The ratio between the value of the parameter under OE and CE conditions was measured. Under OE condition PWS and OG were characterized by higher postural instability than CG, with the PWS group showing poorer balance capacity than OG. The Romberg ratio showed that while OG and CG had lower balance without vision, PWS maintained the same performance changing from OE to CE. The integration of different sensory inputs appears similar in OG and CG with higher postural stability under OE than CE. Balance in PWS is not influenced by the elimination of visual input., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Background: Static posturography is user-friendly technique suitable for the study of the centre of pressure (CoP) trajectory. However, the utility of static posturography in clinical practice is somehow limited and there is a need for reliable approaches to extract physiologically meaningful information from stabilograms. The aim of this study was to quantify the postural strategy of Prader-Willi patients with the fractal dimension technique in addition to the CoP trajectory analysis in time and frequency domain., Methods: 11 adult patients affected by Prader-Willi Syndrome (PWS) and 20 age-matched individuals (, Control Group: CG) were included in this study. Postural acquisitions were conducted by means of a force platform and the participants were required to stand barefoot on the platform with eyes open and heels at standardized distance and position for 30 seconds. Platform data were analysed in time and frequency domain. Fractal Dimension (FD) was also computed., Results: The analysis of CoP vs. time showed that in PWS participants all the parameters were statistically different from CG, with greater displacements along both the antero-posterior and medio-lateral direction and longer CoP tracks. As for frequency analysis, our data showed no significant differences between PWS and CG. FD evidenced that PWS individuals were characterized by greater value in comparison with CG., Conclusions: Our data showed that while the analysis in the frequency domain did not seem to explain the postural deficit in PWS, the FD method appears to provide a more informative description of it and to complement and integrate the time domain analysis.

Background: Improving balance and reducing risk of falls is a relevant issue in Prader-Willi Syndrome (PWS). The present study aims to quantify the effect of a mixed training program on balance in patients with PWS., Methods: Eleven adult PWS patients (mean age: 33.8 ± 4.3 years; mean BMI: 43.3 ± 5.9 Kg/m2) attended a 2-week training program including balance exercises during their hospital stay. At discharge, Group 1 (6 patients) continued the same exercises at home for 6 months, while Group 2 (5 patients) quitted the program. In both groups, a low-calorie, well-balanced diet of 1.200 kcal/day was advised. They were assessed at admission (PRE), after 2 weeks (POST1) and at 6-month (POST2). The assessment consisted of a clinical examination, video recording and 60-second postural evaluation on a force platform. Range of center of pressure (CoP) displacement in the antero-posterior direction (RANGEAP index) and the medio-lateral direction (RANGEML index) and its total trajectory length were computed., Results: At POST1, no significant changes in all of the postural parameters were observed. At completion of the home program (POST2), the postural assessment did not reveal significant modifications. No changes in BMI were observed in PWS at POST2., Conclusions: Our results showed that a long-term mixed, but predominantly home-based training on PWS individuals was not effective in improving balance capacity. Possible causes of the lack of effectiveness of our intervention include lack of training specificity, an inadequate dose of exercise, an underestimation of the neural and sensory component in planning rehabilitation exercise and failed body weight reduction during the training. Also, the physiology of balance instability in these patients may possibly compose a complex puzzle not affected by our exercise training, mainly targeting muscle weakness.

Prader-Willi syndrome (PWS) and Ehlers-Danlos syndrome (EDS) are two different genetical disorders both characterized, among other features, by muscular hypotonia. Postural control seems to be impaired in both conditions. The aim of the present study was to quantitatively compare postural control in adult PWS and EDS using stabilometric platform to unveil possible common determinants of impaired balance. We enrolled 11 PWS and 21 EDS adult patients and 20 age-matched controls. They were instructed to maintain an upright standing position for 30s with open eyes (OEs) focusing on a 6 cm black circle positioned at a distance of 1.5m. Both PWS and EDS patients were characterized by higher RANGEML, RANGEAP and trajectory length of CoP values as compared to CG. No statistically differences were found between PWS and EDS in terms of any of these parameters. The results demonstrated that both PWS and EDS are characterized by a severe postural instability. Muscle hypotonia and weakness may account for reduced balance capacity. Quantitative characterization of instability is important to identify, develop and enhance rehabilitation interventions., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Patients affected by Down (DS) and Prader-Willi syndrome (PWS) are characterised by some common clinical and functional features including gait disorders and reduced postural control. The aim of our study was to quantitatively compare postural control in adult PWS and DS. We studied 12 PWS and 19 DS adult patients matched for age, height, weight and body mass index. They were instructed to maintain an upright standing position on a force platform for 30s with open eyes (OE) and we calculated the range of center of pressure (CoP) displacement in the A/P direction (RANGE(AP)) and in the M/L direction (RANGE(ML)) and the total CoP trajectory length during quiet stance (Sway Path, SP). The range of oscillations in PWS and DS in both AP and ML direction were higher than in controls. PWS and DS were statistically different for RANGE(AP), with PWS showing higher mean values. Our results confirm a reduced capacity of both PWS and DS in maintaining postural stability. This appears to be in some respect different in PWS and DS, with PWS showing poorer control in AP. DS and, particularly, PWS should be encouraged to undergo specific balance training and strengthening of the ankle muscles as part of a comprehensive rehabilitation program to enhance daily functioning and quality of life., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

Being severely overweight is a distinctive clinical feature of Prader-Willi Syndrome (PWS). This explorative study aims to characterise balance capacity in PWS as compared to non-genetically obese patients (O) and to a group of normal-weight individuals (CG). We enrolled 14 PWS patients: 8 females and 6 males (BMI = 41.3 ± 7.3 kg/m(2), age = 32.86+4.42 years), 44 obese individuals, 22 males and 22 females (BMI = 40.6 ± 4.6 kg/m(2), age = 34.2 ± 10.7 years) and 20 controls (CG: 10 females and 10 males; BMI: 21.6 ± 1.6 kg/m(2); age: 30.5 ± 5.3 years). Postural acquisitions were conducted by means of a force platform from which the COP pattern vs time was analysed. The participants were required to stand barefoot on the platform with eyes open and heels at standardized distance and position for 60s. All of the analysed parameters were statistically different from O and CG groups. PWS individuals showed greater displacements in both the A/P and M/L direction (RMS, RANGE and MV indices). Analysis of the overall planar movement of the CoP showed that the PWS patients were characterised by higher RMS distance from the centre (RMS(CoP) index) and area of confidence ellipse (AREA(CoP) index) when compared both to obese and healthy individuals. PWS patients showed a poorer balance capacity than their non-genetically obese counterparts and healthy individuals, with greater differences in both the A/P and M/L direction than O. Rehabilitation programs for PWS should take this finding into account. In addition to weight loss, strengthening of ankle flexors/extensors, and balance training, tailored interventions aimed at improving A/P control should be given particular consideration., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

In addition to hypotonia and relative sarcopenia, patients with Prader-Willi syndrome (PWS) show reduced spontaneous physical activity and gait disorders. Scant evidence exists that daily muscle training increases their lean mass and physical activity levels. Whether adequate long-term physical training is feasible and effective in improving muscle function and gait in PWS is still unknown. Eleven adult PWS patients (mean age: 33.8±4.3 years; mean BMI: 43.3±5.9 kg/m(2)) admitted to our hospital were enrolled in this study. During their hospital stay they attended a 2-week rehabilitation program which included supervised exercise sessions. At discharge, Group 1 (6 patients) continued the same exercises at home for 6 months, while Group 2 (5 patients) did not continue home-based training. They were assessed at admission (PRE), at 2 weeks (POST1) and at 6 months (POST2). The assessment consisted of a clinical examination, 3D gait analysis and muscle strength measurement with an isokinetic dynamometer. After 2 weeks of supervised training (POST1), no significant changes in spatial-temporal gait parameters were observed, although significant improvements in ankle dorsal flexion during stance and swing and knee flexor strength were evidenced by 3D gait analysis and dynamometry in all patients. Following 6 months of home training (POST2), Group 1 had showed significant improvements in cadence and reduced knee hyperextension in mid-stance. Ankle plantar and dorsal flexors isokinetic strength had improved significantly at 120° s(-1), whereas Group 2 showed no changes in their spatial-temporal and kinematic parameters. The present study reinforces the idea that even in participants with PWS who present with a distinctive psychological profile, long-term group interventions are feasible and effective in improving their overall physical functioning. Providing an effective and simple home-based training program represents a continuum of the rehabilitation process outside the hospital, which is a crucial issue in chronic conditions., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

Background: Prader-Willi (PWS) and Down Syndrome (DS) are two genetic disorders characterised by some common clinical and functional features. A quantitative description and comparison of their patterns would contribute to a deeper understanding of the determinants of motor disability in these two syndromes. The aim of this study was to measure gait pattern in PWS and DS in order to provide data for developing evidence-based deficit-specific or common rehabilitation strategies., Methods: 19 PWS patients (17.7-40 yr) and 21 DS patients (18-39 yr) were evaluated with an optoelectronic system and force platforms for measuring kinematic and kinetic parameters during walking. The results were compared with those obtained in a group of normal-weight controls (Control Group: CG; 33.4 + 9.6 yr)., Results and Discussion: The results show that PWS and DS are characterised by different gait strategies. Spatio-temporal parameters indicated a cautious, abnormal gait in both groups, but DS walked with a less stable strategy than PWS. As for kinematics, DS showed a significantly reduced hip and knee flexion, especially at initial contact and ankle range of motion than PWS. DS were characterised by lower ranges of motion (p < 0.05) in all joints than CG and PWS. As for ankle kinetics, both PWS and DS showed a significantly lower push-off during terminal stance than CG, with DS yielding the lowest values. Stiffness at hip and ankle level was increased in DS. PWS showed hip stiffness values close to normal. At ankle level, stiffness was significantly decreased in both groups., Conclusions: Our data show that DS walk with a less physiological gait pattern than PWS. Based on our results, PWS and DS patients need targeted rehabilitation and exercise prescription. Common to both groups is the aim to improve hypotonia, muscle strength and motor control during gait. In DS, improving pelvis and hip range of motion should represent a major specific goal to optimize gait pattern.

Background Prader–Willi syndrome (PWS) is the most frequent type of syndromic obesity and major clinical features include muscular hypotonia, early onset of obesity, short stature, scoliosis, developmental delays, reduced spontaneous physical activity, gait and postural disorders. Improving balance and walking ability in these patients could enhance their health status and quality of life. Objective The aim of this study was to quantify the effects of an Osteopathic Manipulative Treatment (OMT) session on gait pattern and posture in adults with PWS. Methods Ten patients with PWS (age: 37.0 + 4.3 years) were evaluated at admission (PRE session) and 24 h after the conclusion of one single 45-min OMT session (POST session), using gait analysis and static posturography. Two control groups were recruited: the first one included 15 obese subjects and the second group included 20 normal weight subjects. Results After the OMT treatment, significant effects on posture and on walking were reported. In particular, significant improvements were observed in knee kinematics (knee position at initial contact and in mid-stance) and ankle kinetics (in terms of the peaks of ankle moment and power during terminal stance), with higher value of ground reaction force at push-off. Significant improvements were found in terms of postural analysis of the centre of pressure, which decreased its excursion in antero-posterior and medio-lateral direction and its trace length. Conclusions These preliminary results suggest that OMT within a comprehensive rehabilitation program could reduce costs and increase effectiveness of the rehabilitation treatment of these patients. [ABSTRACT FROM AUTHOR]