Foot-ground interaction during upright standing in children with Down syndrome

This study aimed to quantitatively characterize the main foot-ground contact parameters during static upright standing and to assess foot evolution with increasing age in young individuals affected by Down syndrome (DS). To this end, 99 children with DS of mean age 9.7 (1.7) were tested using a pressure sensitive mat, and the raw data were processed to extract information about overall and rearfoot, midfoot and forefoot contact area, Arch Index (AI) and average contact pressure. The values obtained were then compared with those calculated from a sample of age- and gender-matched participants (control group, CG). Children with DS exhibited larger midfoot and reduced forefoot contact areas with respect to CG participants (+53% and -35% respectively, p<0.001), increased AI values (DS 0.31, CG 0.20, p<0.001) and increased average contact pressures in the midfoot and forefoot. The overall foot development for the two groups followed a similar trend, although in individuals with DS a curve that relates increases in midfoot contact area with age is characterized by a steeper gradient, and the forefoot contact area appeared systematically smaller regardless of age. The large prevalence of the flatfoot type in children with DS (which is known to be originated by hypotonia and ligamentous laxity) associated with the presence of higher average contact pressure in midfoot and forefoot justify the need for careful podiatric surveillance throughout childhood to reduce balance and gait impairment which are likely to affect untreated subjects when they reach adulthood.

Quantitative evaluation of facial movement and morphology

OBJECTIVES

The aim of our study was to quantitatively analyze facial motion kinematics by means of an optoelectronic system. In particular, we defined a set of easily recognizable reference points for markerization, and tested the applicability of our markerization method for an exhaustive characterization of the subjects' facial motion through the definition of some kinematic parameters.

METHODS

Thirty healthy subjects (mean age, 24.6 +/- 1.0 years; 15 female and 15 male) participated in the study. A set of markers (diameter, 3 mm) was positioned on several reference points of the face, and some parameters were computed for the characterization of facial morphology and movement, such as ranges of motion, angles, times, and distances.

RESULTS

The protocol was tested for inter-rater and intra-rater reliability by use of intraclass correlation, of which the results were good (between 0.4 and 0.75) to excellent (greater than 0.75). The parameters were useful for characterizing the resting position, mimicry, and speaking movements, and highlighted some distinctions between men and women in facial morphology.

CONCLUSIONS

The protocol can be applied to a variety of facial movements, including speaking. Future works could address the use of the protocol in subjects with disorders and the integrated analysis of kinematic parameters and voice spectrography.

Functional evaluation and rehabilitation engineering

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).

3D gait analysis in patients with hereditary spastic paraparesis and spastic diplegia: a kinematic, kinetic and EMG comparison

The predominant clinical feature of patients with Hereditary Spastic Paraparesis (HSP) is gait disturbance owing to spasticity and weakness of the lower limbs; the spasticity in early-onset disease (infancy or childhood) often cannot be distinguished from mild form of spastic diplegia (SD). The aim of this study was to quantify the gait strategy in HSP and SD children, focusing on the differences between groups as concerns functional limitation during gait. 9 HSP and 16 SD children were evaluated using Gait Analysis; kinematic and kinetic parameters and EMG pattern during walking were identified and calculated to compare the two gait strategies. The results revealed that these two pathologies are characterised by different gait strategies. In particular we found that knee joint, in terms of kinematics and kinetics, and rectus femoris pattern represent discriminatory aspects in order to compare and differentiate gait patterns of HSP and SD children. The findings strongly support the issue that HSP and SD patients need individualised therapeutical program, either neurosurgical or pharmacological treatment, based on the quantification of gait deficiencies and in order to address the peculiarity of their motor limitations and to prevent the onset of compensatory strategies.

Postural control in children, teenagers and adults with Down syndrome

The goal of this work was to analyze postural control in Down syndrome (DS) participants considering three different groups composed by children, teenagers and adults with DS. An analysis of the centre of pressure (COP) displacement during standing position was therefore performed for the three groups of subjects. The obtained signal of COP was then analyzed in both time and frequency domains in order to perform a thorough analysis of the signal. Even if several parameters revealed more differences between the control and DS participants in adulthood, results indicated a divergence of these two groups starting from their early age, although the limit of this study considering a cross-sectional, and not a longitudinal comparison. In particular, COP medio-lateral range of motion pointed out a decrease for both groups considered (pathological and control) in time domain analysis that could lead to the same conclusion in developing strategies, but frequency domain analysis evidenced how this result is reached by the different population: DS people showed a larger frequency of movement in ML more evidenced in adults group (Down Syndrome Adults Group vs. Adults Control Group; 0.35 ± 0.22 Hz vs. 0.17 ± 0.15 Hz; p < 0.05). Even if less pronounced also for the other parameters computed these differences emerged. Aims for the two macro-groups, DS and CG, are different: DS people focused on overcoming the lack of equilibrium caused by hypotonia and ligament laxity, while control group attempted to improve their strategy in term of efficiency, pointing out a different strategy development.

Assessment of gait recovery in children after Traumatic Brain Injury

OBJECTIVE

The aims were: (1) to quantify the functional limitation of children at the beginning of recovery of independent ambulation after Traumatic Brain Injury (TBI), using clinical-functional scales; (2) to evaluate the changes in gait pattern during rehabilitation (about 5 months later), using 3D Gait Analysis (GA) in post-acute phase; (3) to investigate the presence of correlation among parameters obtained by 3DGA, clinical assessment and measures connected with the trauma.

METHODS

Fourteen children with hemiplegia after severe TBI were evaluated at independent gait recovery (S0) and 5.5 months later (S1) by clinical assessment (GOS, DRS, WeeFIM and GMFM) and 3D GA (spatio-temporal parameters, kinematics and kinetics).

RESULTS

At S1 all clinical measures had improved. Regarding spatio-temporal parameters, velocity and step length improved. Significant progress was evident at the ankle joint, while an unchanged condition appeared at pelvis and hip in sagittal plane with a worsening of hip rotation which increased its internal rotation. Significant correlations were found between motor performance, clinical assessment and trauma-related measures.

CONCLUSIONS

Repeated GA and clinical evaluations were useful in quantifying the motor recovery of children with TBI during rehabilitation underpinning the role of GA in quantifying these modifications in an objective and non-invasive way.

Quantitative effects on proximal joints of botulinum toxin treatment for gastrocnemius spasticity: a 4-year-old case study

Botulinum toxin A (BTA) is a recognized treatment for the early management of spasticity in children with Cerebral Palsy. This study quantified with Gait Analysis (GA) the gait pattern of a 4-year-old diplegic child with calf contracture before, 5 days, and 3 months after BTA injections into gastrocnemius. Kinematic and kinetic data of main lower limb joints were investigated. After only 5 days, ankle dorsi-plantarflexion and knee flex-extension improved, but hip joint worsened, increasing its excessive flexion, to compensate the improvement in knee position of the treated limb and to obtain better stability. A worsening of hip power happened. After 3 months, all joints generally improved their position during gait cycle. Hip and knee joints increased their range of movement and improvements occurred at ankle kinematics and kinetisc, too; a better ankle position and an increase of its capacity of propulsion during terminal stance were evident.

Kinematics of trunk movements: protocol design and application in obese females

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.

Quantitative analysis of sit to stand movement: experimental set-up definition and application to healthy and hemiplegic adults

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 strategy of uninvolved limb in children with spastic hemiplegia

AIM

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Clinical implications of gait analysis in the rehabilitation of adult patients with "Prader-Willi" Syndrome: a cross-sectional comparative study ("Prader-Willi" Syndrome vs matched obese patients and healthy subjects)

Background

Being severely overweight is a distinctive clinical feature of Prader-Willi Syndrome (PWS). PWS is a complex multisystem disorder, representing the most common form of genetic obesity. The aim of this study was the analysis of the gait pattern of adult subjects with PWS by using three-Dimensional Gait Analysis. The results were compared with those obtained in a group of obese patients and in a group of healthy subjects.

Methods

Cross-sectional, comparative study: 19 patients with PWS (11 males and 8 females, age: 18–40 years, BMI: 29.3–50.3 kg/m²); 14 obese matched patients (5 males and 9 females, age: 18–40 years, BMI: 34.3–45.2 kg/m²); 20 healthy subjects (10 males and 10 females, age: 21–41 years, BMI: 19.3–25.4 kg/m²). Kinematic and kinetic parameters during walking were assessed by an optoelectronic system and two force platforms.

Results

PWS adult patients walked slower, had a shorter stride length, a lower cadence and a longer stance phase compared with both matched obese, and healthy subjects. Obese matched patients showed spatio-temporal parameters significantly different from healthy subjects.

Furthermore, Range Of Motion (ROM) at knee and ankle, and plantaflexor activity of PWS patients were significantly different between obese and healthy subjects. Obese subjects revealed kinematic and kinetic data similar to healthy subjects.

Conclusion

PWS subjects had a gait pattern significantly different from obese patients. Despite that, both groups had a similar BMI. We suggest that PWS gait abnormalities may be related to abnormalities in the development of motor skills in childhood, due to precocious obesity. A tailored rehabilitation program in early childhood of PWS patients could prevent gait pattern changes.

Quantification of energy expenditure during gait in children affected by cerebral palsy

AIM

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

This inefficiency characteristic of CP deambulation is probably directly connected to the presence of simultaneous contraction of agonist and antagonist muscle in these patients.

Are patients with hereditary spastic paraplegia different from patients with spastic diplegia during walking? Gait evaluation using 3D gait analysis

Patients with hereditary spastic paraplegia (HSP) often resemble patients with mild spastic diplegia (SD), although their motor limitations differ. The aim of this study was to analyse quantitatively the gait of HSP and SD subjects in order to define the gait pattern in HSP and the differences between the two conditions. Fifteen subjects with HSP, 40 patients with SD and 20 healthy subjects underwent gait analysis (GA). The spatio-temporal and kinematic parameters at the proximal joints were found to be similar in HSP and SD, whereas the most significant differences were found at the knee and ankle joints. Both groups displayed a tendency for knee hyperextension in the midstance phase, but the duration of this hyperextension was longer in the HSP patients. This study shows that GA complements traditional clinical evaluations, making it possible to distinguish, clearly, between motor ability in HSP and in SD patients; the duration of the knee hyperextension during midstance was found to discriminate between the two gait patterns.

Gait alteration of a teenager with Down's syndrome: a 5-year follow-up before and after surgery

Aim of this study is to evaluate kinematic and kinetic aspects of gait alteration in a teenager with Down's syndrome before and after surgery. The gait pattern of the participant was evaluated quantitatively by gait analysis at different ages. In the interval between 14 and 16 years, a patella surgery was performed on the right knee joint. A worsening of gait ability in kinematic and kinetic patterns was highlighted before surgical treatment. After surgery, a significant improvement was observed. The 5-year follow-up showed an improvement in the gait ability after the surgery and allowed quantitative evaluation of treatment outcomes.

Computerized gait analysis of Botulinum Toxin treatment in children with cerebral palsy

PURPOSE

Intramuscular botulinum toxin A (BTA) injection is a local reversible treatment with a wide range of therapeutic applications, including temporary reduction of spasticity. The aim of this work was a quantitative, computerized objective evaluation of BTA-induced improvement of the walking functional ability in a group of children with cerebral palsy (CP).

METHODS

Fifteen children with CP and 20 healthy children were evaluated. All patients were equinus walkers without fixed contractures of triceps surae muscles and they were evaluated before and after about 1.5 months from BTA injections into the calf muscles. The effectiveness of treatment was evaluated by 3D computerized gait analysis.

RESULTS

Data analysis revealed a significant improvement of equinus foot and ankle range of motion during gait after BTA injection. Positive effects were evident also at the knee joint as documented by the improvement of kinetics characteristics (moment and power).

CONCLUSIONS

Computerized gait analysis is a valid method for quantification of BTA effect on walking in children with CP, allowing a detailed evaluation of improvement at each joint and a quantitative evaluation of treatment outcome.

Analysis of the correlation between three methods used in the assessment of children with cerebral palsy

The primary aim of this study was to assess the correlations between gait analysis, magnetic resonance imaging (MRI), and Gross Motor Function Measure (GMFM) scores in children with cerebral palsy (CP). These common diagnostic tools were used to evaluate 21 children affected by CP (mean age: 6 years, range: 5-13 years; 8 females and 13 males; 5 left hemiplegics, 4 right hemiplegics, 12 diplegics). In particular, in order to compare gait analysis data with other diagnostic evaluations, the Normalcy Index (NI) was used. The results showed a good correlation between the NI and the results of MRI, and between NI and the GMFM score (r=-0.76). Therefore, this investigation demonstrated that there exists a strong relationship between gait analysis and other clinical evaluation tools.

Quantitative analysis of gait pattern and energy consumption in children with cerebral palsy

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.

Biomechanical evaluation of scapular girdle in patients with chronic arm lymphedema

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.

Gait analysis before and after gastrocnemius fascia lengthening in children with cerebral palsy

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.

Use of the normalcy index for the evaluation of gait pathology

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.

Biomechanical analysis of sit-to-stand movement in normal and obese subjects

OBJECTIVE

Main purpose of this study was to develop a biomechanical model for the analysis of sit-to-stand movement in normal and obese subjects.

DESIGN

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.

BACKGROUND

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.

METHODS

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.

RESULTS

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).

RELEVANCE

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.

Gait analysis in children affected by myelomeningocele: comparison of the various levels of lesion

The aim of this study was to utilise the gait analysis (GA) methodology to characterise the walking act in children with different levels of myelomeningocele. To this end, we analysed 30 children (mean age 11 +/- 3 years, still able to walk without ortheses) grouped according to the site of their neurological lesion (localised from L4 down to S5); ten healthy children (mean age 9 +/- 2 years) were also analysed for comparison. Of the many kinematic and kinetic parameters provided by GA, we focused on those providing a good correlation with the level of lesion. In particular, the following parameters are presented and discussed: angle of flexion at the knee joint at the moment of contact of the foot with the ground, knee joint flexion-extension range of motion, flexion of the hip at the beginning of the stride, anterior pelvic tilt, range of rotation of the pelvis in the horizontal plane and ankle joint power. The higher the level of the neurological lesion, the more these parameters of gait were found to deviate from those measured in the control group. This study emphasises the relationship that exists between the site (level) of the neurological lesion and the individual aspects of the functional limitation associated with it.

Short-term effects of "botulinum toxin a" as treatment for children with cerebral palsy: kinematic and kinetic aspects at the ankle joint

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.

Sit-to-stand movement analysis in obese subjects

OBJECTIVES

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.

DESIGN

Cross-sectional, controlled (obese patients vs controls) study on sit-to-stand movement analysis

SUBJECTS

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).

MEASUREMENTS

Angle parameters carried out from a quantitative three-dimensional analysis of sit-to-stand (STS) movement, using an optoelectronic system.

RESULTS

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.

DISCUSSION

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.

Energy consumption and gait analysis in children with myelomeningocele

The aim of this study was to determine, in children with different levels of myelomeningocele (MMC), the gait pattern and energy cost of walking with and without ankle-foot orthoses (AFOs). We found that each MMC level was characterised by recognisable gait patterns and that the abnormalities closely reflected the muscle deficits present. Furthermore, the study also introduces new indices for evaluating the energy cost of locomotion and demonstrates that the energy required for walking is increased in children with MMC compared with non disabled children. With respect to barefoot conditions, the use of AFOs leads to an improvement in gait and reduced energy consumption.

Kinematic and dynamic analysis of the ankle joint in children with cerebral palsy

The assessment of walking in children affected by cerebral palsy (CP) is currently based principally on qualitative assessment criteria. Gait analysis, meanwhile, evaluates quantitatively kinematic and dynamic aspects of locomotion. The main aim of this study was to examine (using an optoelectronic system and a force platform) kinematic and dynamic aspects of the ankle joint in hemiplegic and in diplegic children (9 and 11 subjects respectively) and in 10 normal control subjects. Our results reveal, in spastic subjects, "equinus" placement of the foot in the initial contact phase, a lack of dorsiflexion (negative DF peak) in the stance phase and a reduction in push-off capacity (capacity to move the leg forward) in the swing phase. The results furnished by this study represent a useful contribution to the assessment of the walking ability of children affected by CP and to the evaluation of the indications and advantages of the rehabilitative intervention chosen.