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ABSTRACT: BACKGROUND: In patients with Down syndrome (DS) one of the most common abnormalities is flat foot which can interfere significantly with normal daily activities, such as gait. The aim of this study was to quantitatively assess the relationship between the flat foot and the gait alterations in DS children. METHOD: Twenty-nine patients with DS and 15 non-affected subjects were assessed using 3D Gait Analysis, using an optoelectronic system, force platforms and video recording. The degree of flat foot was assessed using the arch index and kinematic and kinetic parameters were identified and calculated from 3D Gait Analysis for each study participant. RESULTS: Data showed that ankle plantarflexion moment and ankle power during terminal stance were significant to differentiate the patients with and without flat feet: their peak values were significantly lower for the patients with flat foot. In addition, the research for correlation demonstrated that the higher the arch index value, the lower the peak of ankle moment and of the generated ankle power during terminal stance and the minimum of absorbed ankle power. CONCLUSIONS: Children with flat foot displayed a less functional gait pattern in terms of ankle kinetics than children without flat foot, suggesting that the presence of flat foot may lead to a weaker efficient walking. Then, the increasing flat foot tended to result in lower push-off ability, leading a less functional walking.
Journal of Intellectual Disability Research 01/2013; · 1.88 Impact Factor
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ABSTRACT: The aim of this study was to explore new techniques in analysing postural control using nonlinear time-series analysis and to relate these results with the clinical knowledge on the postural system in Down syndrome (DS) subjects. In order to achieve the goal, we analysed the time domain and the frequency domain behaviour, the fractal dimension and the entropy of the centre of pressure signal in both directions during quiet standing in 35 participants with DS, comparing the results with a control population. DS patients evidenced a lack in postural control in anterior-posterior direction due to the impairment both in the high organisation and synergies and in the impairments due to ligament laxity and hypotonia. Maintaining posture is a task achieved by the integration of visual, vestibular and somatosensory receptors and the dynamical nature of this signal gives fundamental data about the lack of postural control in specific pathological condition.
Computer Methods in Biomechanics and Biomedical Engineering 06/2012; · 0.85 Impact Factor
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A. Aliverti,
C. Frigo,
G. Andreoni,
G. Baroni,
A. Bonarini,
P. Cerveri,
M. Crivellini,
R. Dellaca,
G. Ferrigno, M. Galli,
A. Pedrocchi,
R. Rodano,
G.C. Santambrogio,
G. Tognola,
A. Pedotti
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ABSTRACT: Politecnico di Milano has a long-lasting tradition in the field of movement analysis. Since the early 1980s, methods and technologies for 3-D motion capture have been designed and prototyped at the Dipartimento di Bioingegneria. Mathematical models and numerical simulations of the musculoskeletal and sensory motor control systems have been developed under different conditions, including microgravity and sport activities. These methods and techniques have pioneered the clinical applications of quantitative analysis of movement, posture, equilibrium, gait, and motor control for the evaluation of patients with motor disabilities throughout a multifactorial approach, including not only biomechanics (statics, kinematics, dynamics, and kinetics) but also functional signaling and imaging [EMG, EEG, NIRS, and fMRI]. Important current activities and future perspectives in the fields of functional assessment of the respiratory system and rehabilitation engineering, including quantitative and objective evaluation during the rehabilitation process, developments of man-machine interfaces, rehabilitation robotics, neuroprostheses, functional evaluation and development of advanced orthotic devices, orthopedic surgical treatment planning, sensory augmentation, and substitution, are being developed.
Pulse, IEEE. 07/2011;
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ABSTRACT: The aim of this work was to design a multimodal approach for the investigation of the different factors Motor Learning involves (e.g. planning, execution, correction, ...). Attention was focused onto the issue of Motor Adaptation (MA), which takes place when learning of a partially (but not completely) new motor strategy is needed. We hereby present a report about the methodological set-up which has been developed and tested for the investigation of motor adaptation during repetitive pointing tasks. We exploited the potentialities of the combined use of electroencephalographic and motion analysis techniques to find possible relation between the activity of the central nervous system and the neuro-musculo-skeletal one. The adaptation-related changes in oscillatory brain activity and movement kinematics were monitored during a visually-guided, feedback-controlled, sequence of pointing tasks. Our preliminary results suggest that the proposed protocol: (i) can discern modifications of brain activity in the alpha and beta frequency bands; (ii) is sensible to kinematic alterations; and, (iii), allows a quantitative evaluation of performance in terms of both final result and motor patterns. In this work we identified a bunch of possible neuro-motor biomarkers, which we propose as possible indicators of adaptation.
Engineering in Medicine and Biology Society (EMBC), 2010 Annual International Conference of the IEEE; 10/2010
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ABSTRACT: The design of useful and effective treatment strategies for movement disorders largely depends on the ability to objectively quantify changes in performances, providing reliable outcome measures. Evaluation of ataxia remains mainly assigned to different clinical scales, providing a semi-quantitative assessment. The aim of this study was to quantitatively characterize functional changes in upper limb movements in ataxic patients, using an optoelectronic system for objective measurements.
Fourteen patients with cerebellar ataxia and 27 healthy subjects were analyzed using an optoelectronic system with passive markers during pointing task and hand-to-mouth movement. Quantitative parameters capable of characterizing ataxic movements were defined using recorded kinematics.
In both the considered functional movements, ataxic patients showed increased adjustment during the last phase of movement. The movement was less smooth than that in controls, with a fragmented trajectory presenting more direction changes than controls.
The proposed protocol allows the quantitative characterization of the motion pattern of ataxic subjects in a non-invasive way. We believe that this analysis could represent a good tool for ataxia evaluation in a clinical context such as neurorehabilitation.
European Journal of Neurology 03/2009; 16(2):232-9. · 3.69 Impact Factor
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ABSTRACT: Neuro-muscular adaptations to the loss or increase in body weight may induce postural alterations. The aim of this study was to investigate the effect of body weight alterations on postural stability in patients with anorexia nervosa and bulimia.
The study enrolled 15 women affected by anorexia nervosa (AN), (mean body mass index [BMI] 15.8+/-1.8 kg/m(2)), 15 women affected by bulimia nervosa (BN), (mean BMI 20.1+/-2.9 kg/m(2)) and 11 healthy matched women (HC), (mean BMI 20.1+/-1 kg/m(2)). Two quiet standing conditions with eyes open (EO) and closed (EC) were analysed with an optoelectronic system (Vicon 460, Viconpeak, Oxford, UK) with passive markers to estimate the centre of mass (CoM) position.
BN patients were more unstable than HC, showing statistically significant differences in antero-posterior CoM excursions and path length. AN patients showed non significant differences from HC. Only HC showed differences between EO and EC conditions, with significantly greater excursions in medio-lateral direction in EC condition (P<0.013) as well as an increased sway area (P<0.022).
In BN, musculoskeletal factors seem to play a major role in the diminished postural control, which appear to be linked to body weight fluctuations rather than to BMI absolute values. No clear-cut postural instability was demonstrated in patients with AN as compared to HC. Visual input appears not to affect balance in patients with eating disorders. Possible further causes of postural instability in BN and implications for rehabilitation treatment are discussed.
European journal of physical and rehabilitation medicine 02/2009; 45(3):335-40. · 1.40 Impact Factor
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ABSTRACT: Rising from a chair or sit to stand (STS) is a movement with a great clinical interest: it is meaningful in order to evaluate motor control and stability in patients with functional limitations. STS requires some skills, as coordination between trunk and lower limbs movements, correction of muscles strength, control of equilibrium and stability and it is often considered into clinical evaluation scales of different pathologies. In literature, although some studies are focused on STS, the essential functions of standing up are not well standardized and uniformly defined: for this reason its application in clinical centres is difficult. In this study an experimental set-up for acquisition of STS movement which is suitable for clinical applications has been proposed: first, it was studied in healthy subjects, to define a normative database of this specific motor task, then in pathological subjects (adults with hemiplegia), to quantify their functional limitation, using quantitative kinematic and kinetic parameters. The results showed that this experimental set-up is effective both in healthy and in pathological subjects; some significant parameters were identified and calculated in order to characterise and quantify the functional limitation of patients.
Gait & Posture 08/2008; 28(1):80-5. · 2.12 Impact Factor
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ABSTRACT: The aim of this study is the gait pattern quantification in hemiplegic children with cerebral palsy using 3D Gait Analysis (GA), in order to distinguish kinematic and kinetic features of involved and uninvolved limbs.
Gait pattern of 28 hemiplegic children and 10 healthy children was quantified using GA. Spatial/temporal parameters, kinematic and kinetic parameters of the main joints of lower limbs were identified and calculated.
In hemiplegic patients the gait pattern of uninvolved limbs was found to be different from those of involved limbs and of control group. The uninvolved limbs were characterized by significant longer stance phase, than involved limbs and healthy children. The main differences in kinematics were found at proximal joints: knee joint was more flexed than normality range during most of gait cycle and hip presented high flexion at the beginning of stance and in the swing phase. Ankle kinematics presented values closed to normative data, even if anomalous pattern was generally present. In term of ankle kinetics, excessive absorbed ankle power in the first phase of stance was found and ankle power generation revealed the mean value of its maximum to be closed to normative.
Analysis of kinematic and kinetic parameters indicated that uninvolved limb of hemiplegic children generally presents a unique motor strategy, different from the involved limb and healthy group. Its gait pattern may be related to the search of a better stability in order to optimize gait and it may be a consequence of involved limb strategy due to the pathology.
Europa medicophysica 10/2007; 43(3):303-10.
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ABSTRACT: Children affected by cerebral palsy (CP) are generally characterised by some movement limitations and abnormalities that compromised gait pattern. These disabilities during deambulation may lead to excessive energy cost and so to a compromised energy efficiency.
In this study oxygen expenditure was evaluated during walking in 20 children affected by CP and in 20 healthy children, using Cosmed K4b2 (Cosmed, Italy). From obtained data about energy consumption, some parameters (heart rate, energy expenditure index, oxygen consumption, oxygen cost) were extracted, first in order to quantify energy cost during gait in pathological and healthy subjects and then to underline differences between the 2 groups of children.
In particular, the results obtained revealed that heart rate (bpm) and oxygen consumption (mL/kg/min) mean values didn't differ significantly between normal subjects and those with CP; instead, energy expenditure index (b/m) and oxygen cost (mL/kg/m) presented higher mean values rather than control group at a statistically level and so they revealed to be significant parameters, in order characterized energy expenditure in children affected by CP.
This inefficiency characteristic of CP deambulation is probably directly connected to the presence of simultaneous contraction of agonist and antagonist muscle in these patients.
Europa medicophysica 04/2007; 43(1):7-12.
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ABSTRACT: The presence of arm lymphedema can induce alterations in motor functions and posture. Using an optoelectronic system (ELITE 2002), we evaluated these alterations during a set of tests involving walking, resting and fatigue. The results of our biomechanical analysis demonstrated a limited range of motion of the affected arm, particularly a reduction in swinging during walking tests, and in shoulder retroposition and abduction movements for all patients. After repeated cyclical movements, premature fatigue appeared in the pathological arm. Lymphedema does not appear to cause alterations to the posture of the spine in our study, but drooping of the shoulder homolateral to the lymphedema can occur. This kind of investigation, which is quick, easy, and comfortable for patients with lymphedema, can be a useful method to evaluate functional capacity, thus allowing a quantitative assessment of the loss of function and the optimizing of the rehabilitative protocol.
Lymphology 10/2006; 39(3):132-40. · 1.02 Impact Factor
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ABSTRACT: The normalcy index (NI) has been proposed as a method for quantifying the amount of deviation in a subject's gait, compared to the gait of the average unimpaired person. The NI was computed for a sample of 144 children affected by cerebral palsy, five idiopathic toe-walkers and 12 able-bodied subjects. It was sensitive enough to distinguish unimpaired subjects from idiopathic toe-walkers and to distinguish between the plegic and uninvolved limbs of hemiplegic patients. The NI was robust enough to categorize pathology, ranging from mild disorders to quadriplegia. The NI was found to be clinically applicable, reliable and easy to use, making it a valuable element in the quantitative evaluation of gait pathology.
Gait & Posture 03/2004; 19(1):85-90. · 2.12 Impact Factor
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ABSTRACT: Main purpose of this study was to develop a biomechanical model for the analysis of sit-to-stand movement in normal and obese subjects.
A biomechanical model describing sit-to-stand was developed using kinetic and kinematic experimental data. Trunk flexion, feet movement, knee and hip joint torques were assumed as sensible indexes to discriminate between normal and obese subjects.
Sit-to-stand is a functional task that may become difficult for certain patients. The analysis of its execution provides useful biomechanical information on the motor ability of selected subjects.
Sit-to-stand was recorded using an optoelectronic system and a force platform in 40 obese patients and 10 normal subjects. A biomechanical model was developed using inverse dynamics equations.
Kinematic and kinetic indexes evidenced differences in motion strategy between normal and obese subjects. Obese subjects rise from the chair limiting trunk flexion (mean value: 73.1 degrees ) and moving their feet backwards from initial position (mean deviation: 50 mm). Normal subjects, instead, show a higher trunk flexion (mean value: 49.2 degrees, a lower angular value between trunk and the horizontal means increased flexion) and fixed feet position (mean deviation: 5 mm). As for kinetics, obese patients show knee joint torque higher than hip torque (maximum knee torque: 0.75 Nm/kg; maximum hip torque: 0.59 Nm/kg), while normal subjects show opposite behaviour (maximum knee torque: 0.38 Nm/kg; maximum hip torque: 0.98 Nm/kg).
We found differences in motion strategy between normal and obese subjects performing sit-to-stand movement, which may be used to plan and evaluate rehabilitative treatments.
Clinical Biomechanics 11/2003; 18(8):745-50. · 2.07 Impact Factor
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ABSTRACT: The aim of this study was to evaluate the typical strategies of obese subjects during a sit-to-stand task (a typical daily living activity) and to assess the load conditions of hip, knee and ankle joints.
Cross-sectional, controlled (obese patients vs controls) study on sit-to-stand movement analysis
Ten adult young volunteers (five men and five women, mean age 28, s.d. 3 y; mean BMI 22, s.d. 2.3 kg/m2) and 30 obese subjects 25 women and five men, mean age 39.4, s.d. 13.7 y, mean BMI 40, s.d. 5.9 kg/m2) suffering from chronic lower back pain were analyzed in a sit-to-stand task (10 trials for each subject).
Angle parameters carried out from a quantitative three-dimensional analysis of sit-to-stand (STS) movement, using an optoelectronic system.
STS task in controls was characterized by a fully forward bending strategy of the trunk, while in obese patients at the beginning (first trial) of the STS task they limited the forward bending in order to protect the vertebral column. When fatigue increased during the execution of multiple STS tasks, the protection of the vertebral column was secondary to the execution of the task. In order to limit the muscle fatigue they increased the forward bending in order to decrease knee joint torque.
The analysis of the strategy used by obese patients in STS task can be used in the design of future trials to assess the efficacy of rehabilitative treatment.
International Journal of Obesity 12/2000; 24(11):1488-92. · 4.69 Impact Factor
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ABSTRACT: Botulinum toxin A (BTA) therapy plays several roles in the management of paediatric cerebral palsy (CP). However, few studies contain objective documentation of gait changes. The main aim of this study was to provide objective information on the outcome of the treatment. Gait analysis data from 20 normal subjects and 23 CP children were collected before and after BTA injections into the gastrocnemius-soleus complex. The follow up was performed 1 month after the first injection. The kinematic and kinetic data revealed significant improvements in dynamic ankle dorsiflexion, both in stance and in the swing phase, an improvement of equinus foot upon initial contact and better support in stance. The results of this study are promising, but studies of other joints involved in gait, such as the knee, are also needed.
Functional neurology 16(4):317-23. · 1.52 Impact Factor
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ABSTRACT: Purpose: Whether kinematic analysis of the trunk can provide useful clinical insight into the relationship between function and various spinal conditions is still under debate. The aim of this study was to develop a clinical protocol and an associated biomechanical model to characterize quantitatively the trunk movements in obese subjects. Methods: Twenty (10 obese, 10 control) female subjects were evaluated with an optoelectronic system and passive markers attached to the spine during forward flexion, lateral bending, and rotation of the trunk. Results: We found a systematic error due to skin artifacts of less than 5 degrees in both groups. Intra- and inter-subject standard deviation was less than 6 degrees . Obese subjects demonstrated a significantly reduced motion in the thoracic spine associated with an increased pelvic tilt angle as compared to controls. Conclusions: Our protocol was able to characterize trunk mobility in obese and normal subjects suggesting that kinematics could represent, even in an obese population, a promising method to investigate subclinical spinal disorders and to assess the effectiveness of rehabilitation programs.
Journal of applied biomaterials & biomechanics (JABB) 6(3):178-85. · 0.76 Impact Factor
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ABSTRACT: The measurement of oxygen consumption during walking allows the quantification of gait expenditure, mainly in patients with musculoskeletal disabilities, as in cerebral palsy (CP). In this study, first, an experimental set up for the acquisition of energy consumption during gait analysis (GA) was proposed; secondly, some parameters of energy expenditure were analyzed to characterize pathological gait from an energetic point of view. Twenty CP children and 20 healthy children were evaluated during two consecutive sessions (session 1: only GA was performed; session 2: K4b2 was used during GA acquisition). The results revealed that the experimental set up was comfortable for all subjects. The absence of any differences in GA values between the two sessions showed that the use of a device for energy acquisition does not modify gait pattern. Energy expenditure index and oxygen cost presented abnormal values in comparison with normality and they were significant to quantify energy expenditure in CP children.
Journal of applied biomaterials & biomechanics (JABB) 5(1):28-33. · 0.76 Impact Factor
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ABSTRACT: Equinus deformity is a common problem in children with spastic cerebral palsy (CP). Persistent deformity that interferes with function is treated by surgically lengthening the triceps surae. Surgical approaches carry a recurrence risk of equinus deformity or over correction with the development of calcaneal deformity, crouch and diminished strength for push-off during gait. These aspects interfere with the basic function of the gastrocnemius/soleus complex. This study aimed to analyze kinematic and kinetic effects of gastrocnemius fascia lengthening on gait pattern in children with CP and, in particular, the evaluation of push-off ability before and after treatment. Twenty children with CP were evaluated by clinical examination and three-dimensional gait analysis (GA) before and after (12 months) gastrocnemius fascia lengthening surgery (modified Vulpius' technique) to improve equinus foot and walking. The results showed a significant reduction in equinus foot, represented by a re-duction in the â angle (the angle between the foot and the ground on the sagittal plane) at initial contact (IC), closer to healthy children, and increased ankle power generation during push-off. Even if this result was not of a statistically significant level, it is important because it means that the surgery did not produce a functional weakness. Kinetic results showed an improvement (ankle joint power absorbed and generated) related to a more functional walking behavior. Some improvements concerning the knee joint are significant, in particular, the value of the knee angle at IC and of peak during the swing phase.
Journal of applied biomaterials & biomechanics (JABB) 3(2):98-105. · 0.76 Impact Factor
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ABSTRACT: The aim of this study was to look for a relationship between cerebral volumes computed using a voxel-based morphometry algorithm and walking patterns in individuals with Down's syndrome (DS), in order to investigate the origin of the motor problems in these subjects with a view to developing appropriate rehabilitation programmes. Nine children with DS underwent a gait analysis (GA) protocol that used a 3D motion analysis system, force plates and a video system, and magnetic resonance imaging (MRI). Analysis of GA graphs allowed a series of parameters to be defined and computed in order to quantify gait patterns. By combining some of the parameters it was possible to obtain a 3D description of gait in terms of distance from normal values. Finally, the results of cerebral volume analysis were compared with the gait patterns found. A strong relationship emerged between cerebellar vermis volume reduction and quality of gait and also between grey matter volume reduction of some cerebral areas and asymmetrical gait. An evaluation of high-level motor deficits, reflected in a lack or partial lack of proximal functions, is important in order to define a correct rehabilitation programme.
Functional neurology 24(3):147-52. · 1.52 Impact Factor
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Andrea Aliverti,
C Frigo,
G Andreoni,
G Baroni,
A Bonarini,
P Cerveri,
M Crivellini,
R Dellaca,
G Ferrigno, M Galli,
A Pedrocchi,
R Rodano,
G C Santambrogio,
G Tognola,
A Pedotti
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ABSTRACT: Life is complex and all about movement, which allows us to interact with the environment and communicate with each other. The human nervous system is capable of performing a simultaneous and integrated control of 100-150 mechanical degrees of freedom of movement in the body via tensions generated by about 700 muscles. In its widest context, movement is carried out by a sensory motor system comprising multiple sensors (visual,auditory, and proprioceptive),multiple actuators (muscles acting on the skeletal system),and an intermediary processor that can be summarized as a multiple-input–multiple-output nonlinear dynamic time-varying control system. This grand control system is capable of responding with remarkable accuracy,speed, appropriateness,versatility, and adaptability to a wide spectrum of continuous and discrete stimuli and conditions and is certainly orders of magnitude more complex and sophisticated than the most advanced robotic systems currently available. In the last decades,a great deal of research has been carried out in the fields of functional evaluation of human performance and rehabilitation engineering. These fields combine knowledge, concepts, and methods from across many disciplines (e.g., biomechanics,neuroscience, and physiology), with the aim of developing apparatuses and methods fort he measurement and analysis of complex sensory motor performance and the ultimate goal of enhancing the execution of different tasks in both healthy people and persons with reduced capabilities from different causes (injury, disease, amputation,and neural degeneration).
IEEE pulse. 2(3):24-34.
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ABSTRACT: The ability to get up from a chair is an important component in maintaining independence for elderly persons and for individuals with disabilities. The main aim of this work is to investigate the effect of muscular strengthening on sit-to-stand (STS) movement to get round the muscular weakness that often occur in elderly people. The sit-to-stand movement of 18 young persons and 10 elderly healthy subjects were acquired before and after an electrical stimulation (ES) strengthening cycle. Experimental data collected by using an optoelectronic system (ELITE), an EMG telemetric equipment and a force platform were analysed by using a biomechanical planar model. The rising strategies and hip, knee and ankle joint torques in the two different groups were calculated before and after ES cycle. The results showed that before ES the subjects, both young and elderly, used a strategy characterised by a fully trunk flexion in order to minimise the knee joint torque. After ES cycle we observed a diminished trunk flexion subsequent to the lower limb muscular strengthening. These data give a biomechanical analysis of the importance of joint torques strengths and postural stability in STS task and should be used to study the risk of falls in elderly
Engineering in Medicine and Biology Society, 1998. Proceedings of the 20th Annual International Conference of the IEEE;
