Identifying Fall Risk Predictors by Monitoring Daily Activities at Home Using a Depth Sensor Coupled to Machine Learning Algorithms.

Because of population ageing, fall prevention represents a human, economic, and social issue. Currently, fall-risk is assessed infrequently, and usually only after the first fall occurrence. Home monitoring could improve fall prevention. Our aim was to monitor daily activities at home in order to identify the behavioral parameters that best discriminate high fall risk from low fall risk individuals. Microsoft Kinect sensors were placed in the room of 30 patients temporarily residing in a rehabilitation center. The sensors captured the patients' movements while they were going about their daily activities. Different behavioral parameters, such as speed to sit down, gait speed or total sitting time were extracted and analyzed combining statistical and machine learning algorithms. Our algorithms classified the patients according to their estimated fall risk. The automatic fall risk assessment performed by the algorithms was then benchmarked against fall risk assessments performed by clinicians using the Tinetti test and the Timed Up and Go test. Step length, sit-stand transition and total sitting time were the most discriminant parameters to classify patients according to their fall risk. Coupling step length to the speed required to stand up or the total sitting time gave rise to an error-less classification of the patients, i.e., to the same classification as that of the clinicians. A monitoring system extracting step length and sit-stand transitions at home could complement the clinicians' assessment toolkit and improve fall prevention.

Fast and automatic assessment of fall risk by coupling machine learning algorithms with a depth camera to monitor simple balance tasks.

BACKGROUND: Falls in the elderly constitute a major health issue associated to population ageing. Current clinical tests evaluating fall risk mostly consist in assessing balance abilities. The devices used for these tests can be expensive or inconvenient to set up. We investigated whether, how and to which extent fall risk could be assessed using a low cost ambient sensor to monitor balance tasks. METHOD: Eighty four participants, forty of which were 65 or older, performed eight simple balance tasks in front of a Microsoft Kinect sensor. Custom-made algorithms coupled to the Kinect sensor were used to automatically extract body configuration parameters such as body centroid and dispersion. Participants were then classified in two groups using a clustering method. The clusters were formed based on the parameters measured by the sensor for each balance task. For each participant, fall risk was independently assessed using known risk factors as age and average physical activity, as well as the participant's performance on the Timed Up and Go clinical test. RESULTS: Standing with a normal stance and the eyes closed on a foam pad, and standing with a narrow stance and the eyes closed on regular ground were the two balance tasks for which the classification's outcome best matched fall risk as assessed by the three known risk factors. Standing on a foam pad with eyes closed was the task driving to the most robust results. CONCLUSION: Our method constitutes a simple, fast, and reliable way to assess fall risk more often with elderly people. Importantly, this method requires very little space, time and equipment, so that it could be easily and frequently used by a large number of health professionals, and in particular by family physicians. Therefore, we believe that the use of this method would substantially contribute to improve fall prevention. TRIAL REGISTRATION: CER-VD 2015-00035. Registered 7 December 2015.

Automating the Timed Up and Go Test Using a Depth Camera.

Fall prevention is a human, economic and social issue. The Timed Up and Go (TUG) test is widely used to identify individuals with a high fall risk. However, this test has been criticized because its "diagnostic" is too dependent on the conditions in which it is performed and on the healthcare professionals running it. We used the Microsoft Kinect ambient sensor to automate this test in order to reduce the subjectivity of outcome measures and to provide additional information about patient performance. Each phase of the TUG test was automatically identified from the depth images of the Kinect. Our algorithms accurately measured and assessed the elements usually measured by healthcare professionals. Specifically, average TUG test durations provided by our system differed by only 0.001 s from those measured by clinicians. In addition, our system automatically extracted several additional parameters that allowed us to accurately discriminate low and high fall risk individuals. These additional parameters notably related to the gait and turn pattern, the sitting position and the duration of each phase. Coupling our algorithms to the Kinect ambient sensor can therefore reliably be used to automate the TUG test and perform a more objective, robust and detailed assessment of fall risk.

Incidence and risk factors for care-related pain in children with physical disabilities.

BACKGROUND: The daily life of children with a physical disability is organized around interventions and care, which is coordinated by a multidisciplinary team. Little is known about the incidence of care-related pain in pediatric rehabilitation centers and health facilities for children. AIM: To determine the incidence and intensity of care-related pain in children with physical disabilities, identify risk factors for pain and practices used to prevent care-related pain in pediatric rehabilitation centers and health facilities for children in France. DESIGN: Non-interventional observational study. SETTING: Sixteen pediatric rehabilitation and special education centers in 4 departments of Brittany (France). POPULATION: A number of 280 children with physical disabilities randomly selected (mean age: 12±4 years). Predominant medical diagnosis was nervous system diseases (68%; e.g., cerebral palsy 33%). METHODS: The FLACC-r scale was used to evaluate pain during each care activity or intervention that required physical contact with the child for five consecutive days and one night. RESULTS: The recorded interventions were 7689. Pain was induced by 6% of physical acts, and 48% of children experienced at least one painful act during the study period. Acts that were more frequently associated with pain and had the highest pain intensity were standing frame use, feeding, gentle mobilizations and bladder catheterization. Age, level of dependency and type of act were all risk factors for care-related pain (P<0.01). Pain prevention was used for only 26.5% of acts. CONCLUSIONS: Care-related pain is frequent and under-recognized in pediatric rehabilitation and health facilities for children. All acts that involve direct physical contact can cause pain. Young and severely dependent children are most at risk of pain. CLINICAL REHABILITATION IMPACT: All professionals who are involved in the care of children with a physical disability and significant limitations in activity and participation must be aware of the issue of pain and that pain can be induced by even the most routine physical act. The management of care-related pain requires a benefit-risk analysis, a prevention and pain assessment, and a family-professional partnership. A multidimensional approach is needed for more individualized pain management and to evaluate the impact of pain on children's participation.

No pain, no gain? Children with cerebral palsy and their experience with physiotherapy.

OBJECTIVES: Recent studies have shown that physiotherapy can induce pain in children and young adults with cerebral palsy (CP). There is a lack of knowledge of children's pain experiences during therapy sessions and the specific causes of pain. The main objective of this study was to better understand the experience of children and young adults with CP during physiotherapy sessions and to analyse the coping strategies used by children and therapists. METHODS: Qualitative study with focus groups. Eighteen children/young adults with CP who experienced pain during physiotherapy were interviewed, using focus groups as a source of data collection in a phenomenological perspective. Data collection and analysis were consecutive to ensure that the data saturation point was reached. The transcripts were coded manually using thematic analysis. First, interesting features of the verbatim were coded, then codes were collated into potential themes and then the themes were checked to ensure they worked in relation to the coded extracts. Multiple coding was performed by 3 different researchers, and results were merged at each step. RESULTS: This study confirmed that among the 18 children interviewed (mean [SD] age 13.17 [4.02] years, 10 girls), physiotherapy, particularly stretching, induced pain. Participants reported that the experience of pain led to a dislike of physiotherapy, although some believed that the pain was necessary to show that the treatment was effective. The use of distraction techniques and the relationship with the physiotherapist were key elements associated with the perception and experience of pain. CONCLUSIONS: This study confirmed that patients with CP experience pain during physiotherapy. Stretching seems to be the main source of pain. Beliefs and practices regarding the concept of pain show that physiotherapists need training in this field.

[Autism and pain - a literature review]. / Autisme et douleur - analyse bibliographique.

The purpose of the present article was to assess the available literature concerning pain and autism. First, authors summarized the published articles on pain reactivity in people with autism. Second, the hypotheses envisaged to explain the presence of expressive particularities in people with autism spectrum disorders were reviewed; these included endogenous opioid excess theory, sensorial abnormalities and sociocommunicative deficit. Finally, the present review dealt with the tools available to assess and manage pain in people with autism. In conclusion, the authors revealed the need for more research to obtain more consensual data and provided some recommendations in this domain that were under exploited by the scientific community. From a clinical point of view, more knowledge about pain in people with autism should enable the development of specific assessment tools and, consequently, better pain management in daily care.

Do clowns attenuate pain and anxiety undergoing botulinum toxin injections in children?

OBJECTIVE: Botulinum toxin injection (BTI) is the primary treatment for spasticity in children. Anxiety and pain are important concerns to address to attenuate the discomfort of BTI. The aim of this study was to compare the effectiveness of medical clowns and usual distractions, both added to nitrous oxide (N2O) and analgesic cream, on pain and anxiety during BTI sessions in children. METHODS: The primary outcome was pain evaluated by the Face, Legs, Activity, Cry, Consolability (FLACC) scale. Secondary criteria were pain rated on a Visual Analog Scale (VAS) by the child and parent, anxiety rated on a VAS before and during BTIs by the child and parent(s), rating of the success of the sessions on a 4-point Likert scale by the physician and parent(s), and rating of the benefits of the distraction by the parent(s). Non-parametric tests were used for between-group comparisons. RESULTS: Baseline group characteristics of the clown and control groups did not differ. During 88 BTI sessions (40 with clown distraction and 48 with control distraction) in 59 children (35 boys; 52 with cerebral palsy, 12 with moderate to severe cognitive disorders), median maximal FLACC score was 2.5 (interquartile range [IQR]: 1-4) in the clown group and 3 (IQR: 1-4.3) in the control group. VAS self-reported pain score was 2.5 (IQR: 0-5) and 3 (IQR: 1-6.3) in the clown and control groups (P=0.56), and VAS proxy-reported pain score was 2.5 (IQR: 0.3-3.4) and 3 (IQR: 1-4.5) (P=0.25). After BTI sessions, the 2 groups did not differ in VAS self- and proxy-reported anxiety (P=0.83 and P=0.81). Physician and parent ratings of the success of sessions were similar between the groups (P=0.89 and P=0.11). Parent ratings of the perceived benefits of distraction were higher in the clown than control group (P=0.004). CONCLUSIONS: Although clown distraction was particularly appreciated by parents, it did not significantly reduce pain or anxiety in children as compared with usual distraction. TRIAL REGISTRATION: ClinicalTrials.gov ID: NCT03149263.

The perioperative validity of the visual analog anxiety scale in children: a discriminant and useful instrument in routine clinical practice to optimize postoperative pain management.

BACKGROUND: Because children's anxiety influences pain perception, perioperative anxiety should be evaluated in clinical practice with a unique, useful, and valid tool to optimize pain management. In this study, we evaluated psychometric properties of the visual analog scale (VAS)-anxiety for children and to study its perioperative relevance in clinical practice. METHODS: One hundred children scheduled for elective surgery and general anesthesia were included. VAS-anxiety was measured at four timepoints and compared with both versions of State Spielbergers' questionnaires (State-Trait Anxiety Inventory for Youth [STAIY] and State-Trait Anxiety Inventory for Children [STAIC]) and the modified Yale Preoperative Anxiety Scale. Children's pain, parents' anxiety, and parents' proxy report of children's anxiety were evaluated using VAS. RESULTS: The correlation between STAIC and VAS-anxiety was significant on the day of discharge. Moreover, changes over time were not significant with STAIC, whereas VAS-anxiety was significantly sensitive to changes over time in the two groups of age (7-11 yr and 12-16 yr). A receiver operating characteristic curve, using modified Yale Preoperative Anxiety Scale as reference, determined a VAS-anxiety cutoff at 30 to identify high-anxiety groups. Pain levels were significantly higher when children were anxious (VAS > or = 30) in the postoperative period. Moreover, children's anxiety and pain were higher when parents were anxious. CONCLUSION: VAS-anxiety is a useful and valid tool to assess perioperative anxiety in children aged 7-16 yr. The influence of children's and parents' anxiety on children's postoperative pain suggests that VAS-anxiety should be recommended routinely for postoperative clinical practice to optimize anxiety and pain management.

Automatic measurement of fall risk indicators in timed up and go test.

Fall risk assessment is usually conducted in specialized centers using clinical tests. Most of the time, these tests are performed only after the occurrence of health problems potentially affecting gait and posture stability. Our aim is to define fall risk indicators that could routinely be used at home to automatically monitor the evolution of fall risk over time. We used the standard Timed Up and Go (T.U.G.) test to classify 43 individuals into two classes of fall risk, namely high- vs low- risk. Several parameters related to the gait pattern and the sitting position included in the T.U.G. test were automatically extracted using an ambient sensor (Microsoft Kinect sensor). We were able to correctly classify all individuals using machine learning on the combination of two parameters among gait speed, step length and speed to sit down. Coupled to an ambient sensor installed at home to monitor the relevant parameters in daily activities, these algorithms could therefore be used to assess the evolution of fall risk, thereby improving fall prevention.

Influence of the Size of the Field of View on Visual Perception While Running in a Treadmill-Mediated Virtual Environment.

We investigated how the size of the horizontal field of view (FoV) affects visual speed perception with individuals running on a treadmill. Twelve moderately trained to trained participants ran on a treadmill at two different speeds (8 and 12 km/h) in front of a moving virtual scene. Different masks were used to manipulate the visible visual field, masking either the central or the peripheral area of the virtual scene or showing the full visual field. We asked participants to match the visual speed of the scene to their actual running speed. For each trial, participants indicated whether the scene was moving faster or slower than they were running. Visual speed was adjusted according to the responses using a staircase method until the Point of Subjective Equality was reached, that is until visual and running speed were perceived as matching. For both speeds and all FoV conditions, participants underestimated visual speed relative to the actual running speed. However, this underestimation was significant only when the peripheral FoV was masked. These results confirm that the size of the FoV should absolutely be taken into account for the design of treadmill-mediated virtual environments (VEs).

Regular physical activity modulates perceived visual speed when running in treadmill-mediated virtual environments.

In virtual reality, visual speed is usually underestimated relative to locomotor speed. Here we investigated how physical activity and fitness affect perceived visual speed when running in a treadmill-mediated virtual environment. Thirty healthy participants (ten sedentary individuals, ten team sport players and ten expert runners) ran on a treadmill at two different speeds (8, 12km/h) in front of a moving virtual scene. Participants were asked to match the speed of the visual scene to their running speed (i.e. treadmill speed), indicating for each trial whether the scene was moving slower or faster than the treadmill. The speed of the visual scene was adjusted according to the participant's response using a staircase until visual and running speeds were perceived as equivalent. More sedentary participants underestimated visual speed relative to their actual running speed. Specifically, visual speed had to exceed running speed to be perceived as equivalent. The underestimation of visual speed was speed-dependent, and it was significantly larger for sedentary participants than for team sports players and expert runners. The volume of physical activity per week was found to be the best predictor of visual speed perception for both running speeds, while the perceived effort constituted a good predictor only at 8km/h. Physical fitness, on the other hand turned out to be a poor predictor of visual speed perception. Therefore, in order to enhance users' engagement and their adherence to physical activity programs, the development of "personalized" treadmill-mediated virtual environments should take into account users' personal characteristics to provide the most natural and engaging feedback possible.

Impact of a specific training programme on the neuromodulation of pain in female patient with fibromyalgia (DouFiSport): a 24-month, controlled, randomised, double-blind protocol.

INTRODUCTION: The main symptom of fibromyalgia (FM) is diffuse pain. There is currently no aetiological treatment for FM. However, all pain associations and best practice guidelines strongly advocate the practice of aerobic physical activity to improve the symptoms of FM subjects. The mechanisms of dysfunctional pain are mostly central and related to stress axis dysfunction (autonomic nervous system and corticotropic axis). Our main objective is to assess the efficacy of a specific training programme on endogenous pain control mechanisms in female patients with FM. Further aims include rebalancing the autonomic neurovegetative system, improving quality of life and sleep quality, and reintegrating patients into society and work. METHODS AND ANALYSIS: 110 female patients with FM diagnosed on American College of Rheumatology 2010 criteria, aged 18-65 years and meeting inclusion conditions will be recruited and randomised into two groups (active and semiactive). The training programme will consist of three 45 min sessions per week of supervised, individualised physical activity over 2 years. Only the intensity of the exercises will differ between the two groups (moderate intensity vs low intensity).All outcome measures will be conducted at baseline (T0), after 6-9 months of training (T6-9) and after 24 months of training (T24). The primary endpoint will be an improvement of pain modulation (activation of diffuse noxious inhibitory control) evaluated by the stimulation test. The secondary endpoint will be relief of pain, anxiety, depression, stress, sleep disorders, pain impact on life quality, and improved heart rate, blood pressure and salivary cortisol. ETHICS AND DISSEMINATION: This study is approved by the Committee for the Protection of Persons West VI. The results will be published in specialised scientific journals and will be presented at scientific meetings on pain and/or physical activity. TRIAL REGISTRATION NUMBER: NCT02486965; Pre-results.

Vocal and verbal expression of postoperative pain in preschoolers.

The purpose of this study was to examine the development and construction of vocal and verbal expression of postoperative pain in young children with limited linguistic abilities. The main objective was to highlight specific pain vocalizations, which may lead to easy and quick detection and assessment of postoperative pain relative to the age of the suffering child. Forty-seven children aged 1 to 6 years were observed during two periods of surgical hospitalization: a preoperative and a postoperative period. The results showed that there was a significant relation between their age and the types of vocalization they expressed during the postoperative period. Regarding the development in relation to certain contexts, a minor modification seems to be concerned not with the type but with the frequency of the items of vocalizations. The study confirms earlier observations and clinical experience that an efficient and reliable assessment of pain in infants and young children necessitates taking several factors into account, such as the developmental age of the children, and especially a consideration of the whole spectrum of pain markers present in the child's behavior and captured by the assessment tools.

Validation of an ambient system for the measurement of gait parameters.

Fall risk in elderly people is usually assessed using clinical tests. These tests consist in a subjective evaluation of gait performed by healthcare professionals, most of the time shortly after the first fall occurrence. We propose to complement this one-time, subjective evaluation, by a more quantitative analysis of the gait pattern using a Microsoft Kinect. To evaluate the potential of the Kinect sensor for such a quantitative gait analysis, we benchmarked its performance against that of a gold-standard motion capture system, namely the OptiTrack. The "Kinect" analysis relied on a home-made algorithm specifically developed for this sensor, whereas the OptiTrack analysis relied on the "built-in" OptiTrack algorithm. We measured different gait parameters as step length, step duration, cadence, and gait speed in twenty-five subjects, and compared the results respectively provided by the Kinect and OptiTrack systems. These comparisons were performed using Bland-Altman plot (95% bias and limits of agreement), percentage error, Spearman's correlation coefficient, concordance correlation coefficient and intra-class correlation. The agreement between the measurements made with the two motion capture systems was very high, demonstrating that associated with the right algorithm, the Kinect is a very reliable and valuable tool to analyze gait. Importantly, the measured spatio-temporal parameters varied significantly between age groups, step length and gait speed proving the most effective discriminating parameters. Kinect-monitoring and quantitative gait pattern analysis could therefore be routinely used to complete subjective clinical evaluation in order to improve fall risk assessment during rehabilitation.

Matching optical flow to motor speed in virtual reality while running on a treadmill.

We investigated how visual and kinaesthetic/efferent information is integrated for speed perception in running. Twelve moderately trained to trained subjects ran on a treadmill at three different speeds (8, 10, 12 km/h) in front of a moving virtual scene. They were asked to match the visual speed of the scene to their running speed-i.e., treadmill's speed. For each trial, participants indicated whether the scene was moving slower or faster than they were running. Visual speed was adjusted according to their response using a staircase until the Point of Subjective Equality (PSE) was reached, i.e., until visual and running speed were perceived as equivalent. For all three running speeds, participants systematically underestimated the visual speed relative to their actual running speed. Indeed, the speed of the visual scene had to exceed the actual running speed in order to be perceived as equivalent to the treadmill speed. The underestimation of visual speed was speed-dependent, and percentage of underestimation relative to running speed ranged from 15% at 8km/h to 31% at 12km/h. We suggest that this fact should be taken into consideration to improve the design of attractive treadmill-mediated virtual environments enhancing engagement into physical activity for healthier lifestyles and disease prevention and care.

Care-related pain and discomfort in children with motor disabilities in rehabilitation centres.

BACKGROUND: Pain is one of the symptoms reported most by children with motor disabilities particularly during daily living activities in institutions and during rehabilitation. Despite the care and consideration of professionals, a wide range of motor and cognitive disabilities, limited communication skills, the presence of chronic pain and frequent care interventions place such children at high risk of experiencing induced pain. OBJECTIVES: We aimed to identify care-related pain and discomfort in children with motor disabilities in rehabilitation centres and the characteristics of children at risk of induced pain. A further aim was to evaluate the validity of a method for the continuous assessment of care-related pain. METHODS: Patients were recruited from 2 paediatric rehabilitation centres. The level of pain or discomfort experienced during each daily care activity was evaluated for 5 days and 1 night by using the FLACC-r scale and a visual analog scale (VAS) rated by the caregiver (VAS caregiver) and the patient (VAS patient). RESULTS: We included 32 children (mean age: 8.5±5 years, range: 1-15 years) with 1302 care activities evaluated. Overall, 3.6% of the activities were rated as painful and 11% uncomfortable. The most frequent painful activities were mouth care, transfers standing and dressing. The most frequent uncomfortable activities were passive limb mobilisation, dressing and transfers. Children with neurological disorders were at increased risk of induced pain. CONCLUSIONS: Children with motor disabilities experienced pain during daily care activities. The methodology we propose is valid and can be used in any type of institution for children with motor disability to evaluate and reduce the frequency of care-related pain.

Person identification from gait analysis with a depth camera at home.

The aim of our project is to develop a markerless system to detect falls and evaluate the frailty of elderly people at home. In previous work, we developed an algorithm detecting falls and daily life activities based on depth images provided by Microsoft's Kinect sensor. We also developed another algorithm based on the same features for gait analysis. However, an ambient system installed at home for frailty evaluation should be able to identify the individuals that one wishes to monitor. This paper proposes a method to identify individuals based on the depth images of gait sequences. The gait sequences are detected using previously presented results on activity recognition based on Hidden Markov Models (HMMs). The visibility of the person in the sequence is assessed from the likelihood of the sequence. We propose to perform the identification of the person from her height and gait in sequences in which she walks being fully visible. The gait pattern of the person is modeled using a HMM built from features of the trajectory of the centre of mass. A specific HMM is built for each person to be identified. This approach also allows us to identify unknown individuals who do not correspond to any of the built HMMs. We test the algorithm with 10 known and 2 unknown individuals. The results show that the presented method differentiates accurately enough the unknown and known individuals, and in the last case identifies correctly the individuals. In other words, our algorithm is able to identify the person of interest among other known (family, caregivers) or unknown persons (occasional individuals).

A gait analysis method based on a depth camera for fall prevention.

This paper proposes a markerless system whose purpose is to help preventing falls of elderly people at home. To track human movements, the Microsoft Kinect camera is used which allows to acquire at the same time a RGB image and a depth image. Several articles show that the analysis of some gait parameters could allow fall risk assessment. We developed a system which extracts three gait parameters (the length and the duration of steps and the speed of the gait) by tracking the center of mass of the person. To check the validity of our system, the accuracy of the gait parameters obtained with the camera is evaluated. In an experiment, eleven subjects walked on an actimetric carpet, perpendicularly to the camera which filmed the scene. The three gait parameters obtained by the carpet are compared with those of the camera. In this study, four situations were tested to evaluate the robustness of our model. The subjects walked normally, making small steps, wearing a skirt and in front of the camera. The results showed that the system is accurate when there is one camera fixed perpendicularly. Thus we believe that the presented method is accurate enough to be used in real fall prevention applications.

Human activities recognition with RGB-Depth camera using HMM.

Fall detection remains today an open issue for improving elderly people security. It is all the more pertinent today when more and more elderly people stay longer and longer at home. In this paper, we propose a method to detect fall using a system made up of RGB-Depth cameras. The major benefit of our approach is its low cost and the fact that the system is easy to distribute and install. In few words, the method is based on the detection in real time of the center of mass of any mobile object or person accurately determining its position in the 3D space and its velocity. We demonstrate in this paper that this information is adequate and robust enough for labeling the activity of a person among 8 possible situations. An evaluation has been conducted within a real smart environment with 26 subjects which were performing any of the eight activities (sitting, walking, going up, squatting, lying on a couch, falling, bending and lying down). Seven out of these eight activities were correctly detected among which falling which was detected without false positives.

How do children with autism spectrum disorders express pain? A comparison with developmentally delayed and typically developing children.

There is a lack of knowledge about pain reactions in children with autism spectrum disorders (ASD), who have often been considered as insensitive to pain. The objective of this study was to describe the facial, behavioral and physiological reactions of children with ASD during venipuncture and to compare them to the reactions of children with an intellectual disability and nonimpaired control children. We also examined the relation between developmental age and pain reactions. The sample included 35 children with ASD, 32 children with an intellectual disability, and 36 nonimpaired children. The children were videotaped during venipuncture and their heart rate was recorded. Facial reactions were assessed using the Child Facial Coding System (CFCS) and behavioral reactions were scored using the Noncommunicating Children's Pain Checklist (NCCPC). A linear mixed-effects model showed that children's reactions increased between baseline and venipuncture and decreased between the end of venipuncture and the recovery period. There was no significant difference between groups regarding the amount of facial, behavioral and physiological reactions. However, behavioral reactions seemed to remain high in children with ASD after the end of the venipuncture, in contrast with children in the 2 other groups. Moreover, we observed a significant decrease in pain expression with age in nonimpaired children, but no such effect was found regarding children with ASD. The data reveal that children with ASD displayed a significant pain reaction in this situation and tend to recover more slowly after the painful experience. Improvement in pain assessment and management in this population is necessary.