Instrumental assessment of dynamic postural stability in patients with unilateral vestibular hypofunction during straight, curved, and blindfolded gait.

PURPOSE: To characterise dynamic postural stability of gait in patients with vestibular hypofunction (PwVH) using a sensor-based assessment while performing dynamic tasks and to correlate the results of this evaluation with clinical scales. METHODS: This cross-sectional study involved 22 adults between 18 and 70 years old from a healthcare hospital centre. Eleven patients suffering from chronic vestibular hypofunction (PwVH) and eleven healthy controls (HC) were evaluated through a combined inertial sensor-based and clinical scale assessment. Participants were equipped with five synchronised inertial measurement units (IMUs) (128 Hz, Opal, APDM, Portland, OR, USA): three IMUs were located on the occipital cranium bone, near the lambdoid suture of the head, at the centre of the sternum, and at L4/L5 level, just above the pelvis, and were used to quantify gait quality parameters, while the other two were located slightly above lateral malleoli and used to perform stride and step segmentation. Three different motor tasks were performed in a randomized order: the 10-m Walk Test (10mWT), the Figure of Eight Walk Test (Fo8WT) and the Fukuda Stepping Test (FST). A set of gait quality parameters related to stability, symmetry and smoothness of gait were extracted from IMU data and correlated with the clinical scale scores. PwVH and HC results were compared to test for significant between-group differences. RESULTS: Significant differences were found for the three motor tasks (10mWT, Fo8WT and FST) when comparing PwVH and HC groups. For the 10mWT and the Fo8WT, significant differences between the PwVH and HC groups were found for the stability indexes. Considering the FST, significant differences between the PwVH and HC groups were also found in the stability and symmetry of gait. A significant correlation was found between the Dizziness Handicap Inventory and gait indices during the Fo8WT. CONCLUSIONS: In this study, we characterized the dynamic postural stability alterations during linear, curved, and blindfolded walking/stepping in PwVH combining an instrumental IMU-based with traditional clinical scales approach. Combining instrumental and clinical evaluation for dynamic stability of gait alterations in PwVH is useful in thoroughly evaluating the effects of unilateral vestibular hypofunction.

Assessing motor competence in kicking in individuals with Down syndrome through wearable motion sensors.

BACKGROUND: Kicking a ball is a very frequent action in sport and leisure time activities and a low proficiency in this skill could limit the participation in recreational sport activities. This issue is emphasised in individuals with Down syndrome (IDS) for which data about motor competence in kicking are limited to children. Here, we aim at evaluating the kicking competence of IDS combining a qualitative and a quantitative method. METHODS: Twenty-three adult IDS and 21 typically developed individuals (ITD) volunteered to participate in the study. Peak-to-peak 3D linear acceleration and angular velocity were recorded at 200 samples/s using two inertial measurement units placed on the lower back and lateral malleolus of the dominant limb during kicking. Motor competence in kicking was assessed according to the criteria proposed in the test of gross motor development version 3 (TGMD-3). RESULTS: Individuals with Down syndrome showed lower motor competence (ITD: 5.9 ± 1.2; IDS: 3.2 ± 2.0) and lower angular velocities about the cranio-caudal (ITD: 3.0 ± 1.8; IDS: 2.1 ± 1.1 rad/s) and medio-lateral axes (ITD: 4.5 ± 1.5; IDS: 3.0 ± 1.1 rad/s) of the trunk compared with ITD. Shank angular velocity about the medio-lateral axis was lower in IDS (ITD: 14.3.6 ± 4.0; IDS: 9.9 ± 2.8 rad/s). CONCLUSIONS: The lower trunk angular velocity in IDS may limit the possibility to rely on the proximal-to-distal sequencing commonly observed in kicking and generate high shank angular velocity upon ball impact. The lower trunk angular velocity may result from orthopaedic features of the pelvic girdle and possibly from a poorer neuromuscular control of core muscles.

Magnetic-free Extended Kalman Filter for upper limb kinematic assessment in Yoga.

Human motion analysis is gaining increased importance in several fields, from movement assessment in rehabilitation to recreational applications such as virtual coaching. Among all the technologies involved in motion capture, Magneto-Inertial Measurements Units (MIMUs) is one of the most promising due to their small dimensions and low costs. Nevertheless, their usage is strongly limited by different error sources, among which magnetic disturbances, which are particularly problematic in indoor environments. Inertial Measurement Units (IMUs) could, thus, be considered as alternative solution. Indeed, relying exclusively on accelerometers and gyroscopes, they are insensitive to magnetic disturbances. Even if the literature has started to propose few algorithms that do not take into account magnetometer input, their application is limited to robotics and aviation. The aim of the present work is to introduce a magnetic-free quaternion based Extended Kalman filter for upper limb kinematic assessment in human motion (i.e., yoga). The algorithm was tested on five expert yoga trainers during the execution of the sun salutation sequence. Joint angle estimations were compared with the ones obtained from an optoelectronic reference system by evaluating the Mean Absolute Errors (MAEs) and Pearson's correlation coefficients. The achieved worst-case was 6.17°, while the best one was 2.65° for MAEs mean values. The accuracy of the algorithm was further confirmed by the high values of the Pearson's correlation coefficients (lowest mean value of 0.86).Clinical Relevance- The proposed work validated a magnetic free algorithm for kinematic reconstruction with inertial units. It could be used as a wearable solution to track human movements in indoor environments being insensitive to magnetic disturbances, and thus could be potentially used also for rehabilitation purposes.

Muscle synergies in archery: an explorative study on experienced athletes with and without physical disability.

Archery technique requires a coordinated activation of shoulder girdle and upper extremity muscles to perform a successful shot. The analysis of muscle synergies can provide information about the motor strategy that underlies the shooting performance, also supporting the investigation of motor impairments in athletes with disability. For this purpose, electromyographic (EMG) data from five muscles were collected from a non-disabled and a W1 category Paralympic athlete, and muscle synergies were extracted from EMG envelopes using non-negative matrix factorization. Muscle synergies analysis revealed features of the motor strategy specific to the athletes' shooting technique, such as the contribution of the biceps muscle instead of the posterior deltoid during the arrow drawing and target aiming in the Paralympic athlete compared to the non-disabled athlete. It is concluded that the evaluation of the muscle synergies may be a valuable tool for exploring the motor strategies adopted by athletes with disability, providing useful information to improve athletic performance and possibly prevent the risk of injury.

The Hybrid Subischial Socket for Persons With Transfemoral Amputation: Gait Parameters and Clinical Assessment of a Case Series.

BACKGROUND: The subischial socket interface design is a promising new shape of socket for persons with transfemoral amputation. Typically, the proximal trim line is located distal to the ischial tuberosity, improving comfort in prosthetic users without interfering with gait parameters compared to Ischial Containment Socket (ICS). No studies have investigated the performances of a subischial sockets with suction suspension system. A new subischial socket (Hybrid Subischial Socket - HySS) combined with a hypobaric passive suspension system has been recently developed. OBJECTIVE: To assess the effects of HySS in terms of comfort, hip range-of-motion and gait parameters. METHODOLOGY: Three persons with transfemoral amputation were tested first using their usual ICS and then after one month of continuous use of HySS. FINDINGS: The following parameters improved in all participants using HySS: 1) hip range-of-motion, 2) walking speed and distance, 3) Timed-Up-and-Go-Test time, 4) stride length, 5) double support duration, 6) peak value of hip extension during stance, 7) satisfaction with the prosthesis. CONCLUSION: These findings suggest that the use of HySS could allow improvements for prosthetic use.

Dynamic balance assessment during gait in children with Down and Prader-Willi syndromes using inertial sensors.

Down (DS) and Prader-Willi (PWS) syndromes are chromosomal disorders both characterized by obesity, ligament laxity, and hypotonia, the latter associated with gait instability. Although these shared features may justify a common rehabilitation approach, evidence exists that adults with DS and PWS adopt different postural and walking strategies. The development of an instrumented protocol able to describe these strategies and quantify patients' gait stability in the current clinical routine would be of great benefit for health professionals, allowing them to design personalized rehabilitation programs. This is particularly true for children with DS and PWS, where motor development is dramatically constrained by severe hypotonia and muscle weakness. The aim of this study was, thus, to propose an instrumented protocol, integrated with the clinical routine and based on the use of wearable inertial sensors, to assess gait stability in DS and PWS children. Fifteen children with DS, 11 children with PWS, and 12 typically developing children (CG) were involved in the study. Participants performed a 10-meter walking test while wearing four inertial sensors located at pelvis, sternum, and both distal tibiae levels. Spatiotemporal parameters (walking speed, stride frequency, and stride length) and a set of indices related to gait symmetry and upper-body stability (Root Mean Square, Attenuation Coefficient and Improved Harmonic Ratio) were estimated from pelvis and sternum accelerations. The Gross Motor Functional Measures (GMFM-88) and Intelligence Quotient (IQ Wechsler) were also assessed for each patient. A correlation analysis among the GMFM-88 and IQ scales and the estimated parameters was then performed. Children with DS and PWS exhibit reduced gait symmetry and higher accelerations at pelvis level than CG. While these accelerations are attenuated by about 40% at sternum level in CG and DS, PWS children display significant smaller attenuations, thus reporting reduced gait stability, most likely due to their typical "Trendelenburg gait". Significant correlations were found between the estimated parameters and the GMFM-88 scale when considering the whole PWS and DS group and the PWS group alone. These results promote the adoption of wearable technology in clinical routines to monitor gait patterns in children with DS and PWS: the proposed protocol allows to markedly characterize patient-specific motor limitations even when clinical assessment scores provide similar results in terms of pathology severity. This protocol could be adopted to support health professionals in designing personalized treatments that, in turn, could help improving patients' quality of life in terms of both physical and social perspectives.

Mechanisms of head stability during gait initiation in young and older women: A neuro-mechanical analysis.

Decreased head stability has been reported in older women during locomotor transitions such as the initiation of gait. The aim of the study was to investigate the neuro-mechanical mechanisms underpinning head stabilisation in young and older women during gait initiation. Eleven young (23.1 ±â€¯1.1 yrs) and 12 older (73.9 ±â€¯2.4 yrs) women initiated walking at comfortable speed while focussing on a fixed visual target at eye level. A stereophotogrammetric system was used to assess variability of angular displacement and RMS acceleration of the pelvis, trunk and head, and dynamic stability in the anteroposterior and mediolateral directions. Latency of muscle activation in the sternocleidomastoid, and upper and lower trunk muscles were determined by surface electromyography. Older displayed higher variability of head angular displacement, and a decreased ability to attenuate accelerations from trunk to head, compared to young in the anteroposterior but not mediolateral direction. Moreover, older displayed a delayed onset of sternocleidomastoid activation than young. In conclusion, the age-related decrease in head stability could be attributed to an impaired ability to attenuate accelerations from trunk to head along with delayed onset of neck muscles activation.

A neurofuzzy inference system based on biomechanical features for the evaluation of the effects of physical training.

The current study aimed to evaluate physical training effects. For this purpose, a classifier was implemented by taking into account biomechanical features selected from force-plate measurements and a neurofuzzy algorithm for data management and relevant decision-making. Measurements included two sets of sit-to-stand (STS) trials involving two homogeneous groups, experimental and control, of elders. They were carried out before and after a 12-week heavy resistance strength-training program undergone by the experimental group. Pre- and post-training differences were analysed, and percentages of membership to "trained" and "untrained" fuzzy sets calculated. The method was shown to be appropriate for detecting significant training-related changes. Detection accuracy was higher than 87%. Slightly weaker results were obtained using a neural approach, suggesting the need for a larger sample size. In conclusion, the use of a set of biomechanical features and of a neurofuzzy algorithm allowed to propose a global score for evaluating the effectiveness of a specific training program.

Extraction of information on elder motor ability from clinical and biomechanical data through data mining.

This study aimed at evaluating the additional knowledge provided by a biomechanical test coupled with clinical tests for motor ability assessment. A database including clinical test scores and sit-to-stand test variables obtained from 110 medically stable elderly subjects was submitted to data mining by searching for association rules. The presence of rules revealed some redundancies due to sample homogeneity, as mainly observed in the joint analysis of a questionnaire for daily activities assessment (Nottingham test) and the sit-to-stand, and due to similar evaluated information, as resulted from the joint analysis of a balance and gait scale (Tinetti test) and the sit-to-stand. Conversely, when no association rules were found, the tests carried unrelated information. The associations mined while analysing these clinical tests encouraged the integration of biomechanical tests, increasing significantly its clinical applicability and reducing the information redundancy. The information extracted also allowed to highlight rules typical of elderly persons that may serve as a knowledge-based tool for the detection of possible deviation from normality.

Disease history in 382 Italian patients with Crohn's disease.

AIMS: This large-scale study was aimed at evaluating the long-term history of Crohn's disease in a cohort of consecutive patients referred to the Careggi Hospital in Florence from January 1973 to June 1996. PATIENTS: A total of 382 patients (187 females, 195 males; mean age of 47 years) were included in our study. The median follow-up was more than 11 years and only 46 patients (12%) had a follow-up of less than 1 year. The main endpoints evaluated in these patients included mortality for any cause, disease-specific mortality, recurrences, and need for surgery. Furthermore, in a subgroup of 130 patients observed during the last 6 months of our study, a more detailed assessment of the disease was carried out in which the distribution of inflammatory, fibrostenosing and fistulizing forms was determined. RESULTS: Our results showed that the disease-specific mortality rate was extremely low (around 3% at 10 years and 5% at 20 years), but the rate of recurrence was approximately 50% at 3 years and more than 60% at 6 years. Surgery was needed in more than 50% of the patients over the 10 years following diagnosis, and the risk of a second operation was of a further 30% within 4 years of the first operation. CONCLUSIONS: These epidemiological data emerging from our study are interesting since a large patient population was evaluated and the duration of the follow-up is extremely long.

A population-based study of inflammatory bowel disease in Florence over 15 years (1978-92).

BACKGROUND: In the group of inflammatory bowel disease (IBD), ulcerative colitis (UC) and Crohn's disease (CD) are considered to be more frequent in Western countries and in areas with a high socioeconomic development but relatively infrequent in southern Europe. Sporadic reports have indicated a lower incidence and a milder course of the disease in Mediterranean countries. Although conclusive data on this point are still lacking, recent reports suggest an increase in both incidence and prevalence rates. METHODS: The incidence of UC and CD during the period January 1978 to December 1992 and their prevalence on 31 December 1992 were estimated in the 15-year-old population of the metropolitan area of Florence. Clinical, demographic, and follow-up information was collected for all identified IBD patients. RESULTS: A total of 796 residents (345 females and 454 males) were newly diagnosed as having IBD during the study period. Of these 593 had UC and 203 CD. The age-standardized incidence rates, calculated for each of five 3-year consecutive periods, rose from 3.8 (in 1978-80) to 9.6 per 100,000 person-years (in 1990-92) for UC and from 1.9 (in 1978-80) to 3.4 (in 1990-92) for CD. Both trends were statistically significant. The prevalence estimated on 31 December 1992 was 121.0 and 40.0 per 100,000 inhabitants for UC and CD, respectively. CONCLUSIONS: Our results confirm that IBD incidence rates and prevalence in this area of central Italy are currently comparable with those reported in northern Europe. These data are necessary for planning adequate health care services for IBD patients.

Defined-formula diets versus steroids in the treatment of active Crohn's disease: a meta-analysis.

BACKGROUND: To compare the effectiveness of defined-formula diets versus steroids for the treatment of active Crohn's disease, we conducted a meta-analysis of the published clinical trials. METHODS: Standard techniques for literature search were used to identify the pertinent trials. All studies included in our meta-analysis (n = 7) were aimed at comparing defined-formula diets versus steroids, using a randomized design. The patient-specific end-point of the meta-analysis was the occurrence of a treatment failure. RESULTS: Our meta-analysis indicated that steroids are more effective than defined-formula diets for inducing remission in active Crohn's disease. In fact, the relative risk of treatment failure (RTF) was significantly lower in the steroid group than in the diet group (risk values for patients given steroids compared with patients given diet: a) method of Mantel-Haenszel: RTF = 0.35; 95% confidence interval, 0.23-0.53; p < 0.001; b) method of Der Simonian & Laird: RTF = 0.43; 95% confidence interval, <0-0.94; p = 0.03). A separate analysis was carried out in which only the subgroup of patients who were not intolerant to diet were evaluated; this analysis also showed a superiority of steroids over diet. CONCLUSIONS: The data examined in this meta-analysis do not support the use of diets as primary treatment for acute exacerbations of Crohn's disease in adults.

Randomised trial of epirubicin versus fluorouracil in advanced gastric cancer. An International Collaborative Cancer Group (ICCG) study.

BACKGROUND: It is not yet established whether doses of epirubicin equitoxic to adriamycin are more effective in the treatment of locally advanced or metastatic gastric cancer. PATIENTS AND METHODS: Seventy patients with advanced gastric cancer were randomised to receive fluorouracil (500 mg/m2 days 1-5 every three weeks) or epirubicin (100 mg/m2 every three weeks), with doses escalating to a maximum dose of 700 mg/m2 of fluorouracil or 140 mg/m2 of epirubicin. RESULTS: No patients attained complete response. Partial response was seen in 3 patients in the epirubicin arm (8%) compared with 2 patients in the fluorouracil arm (6%). No statistically significant difference between the two treatments was seen in either response or survival. Severe side effects, particularly alopecia, and nausea and vomiting were more common in the epirubicin arm (45% and 37%, respectively) compared with the fluorouracil arm (12% and 8%, respectively). CONCLUSIONS: Our trial demonstrates that fluorouracil and epirubicin as single agents have comparable but insufficient activity in advanced gastric cancer.

Epidemiology of inflammatory bowel disease over a 10-year period in Florence (1978-1987).

The epidemiology of inflammatory bowel disease (IBD) in southern Europe is still not well-known. Sporadic reports have suggested a lower incidence and a milder course of the disease in Italy, but conclusive data are still lacking. To shed light on this issue, we conducted a retrospective study of IBD incidence (from January 1978 to December 1987) in the metropolitan area of Florence (650,000 inhabitants). We also estimated IBD prevalence at December 31, 1987. Our study included both in-patients and out-patients referred to the Gastroenterological and Surgical Departments of the area. The diagnosis was based on well-established clinical, endoscopical, radiological, histological and surgical criteria. Overall, nine-hundred IBD patients were identified, but only 359 (195 males, 164 females) met the eligibility criteria for inclusion in the incidence study (area of residence and period of diagnosis); of these, 263 had ulcerative colitis (UC), 96 had Crohn's disease (CD), and 6 had IBD. The average incidence rate of CD was 1.5/100,000 per year while its prevalence was 17.3/100,000. The average incidence rate of UC was 4.0/100,000 per year and the prevalence was 49.6/100,000. Both the incidence and the prevalence rates for UC and CD were higher in males than in females. This retrospective, hospital-based study shows that, in this area, the incidence rate of IBD has steadily increased over the period considered. Further studies specifically focused on risk factors are needed.

Combined therapy with 5-aminosalicylic tablets and enemas for maintaining remission in ulcerative colitis.

A combined therapy with 5-aminosalicylic (5-ASA) tablets (1.6gr/day) and 5-ASA enemas (4gr/twice weekly) was evaluated for maintaining remission of ulcerative colitis in 40 patients. All patients were in complete remission which had been maintained for at least 1 month. The remission was assessed by clinical, endoscopic and histological criteria. Clinical and endoscopical evaluations were performed at intervals of 2 and 6 months, respectively. The relapse-rate associated with this combined therapy was 7.5% at 6 months and 16% at 12 months. In comparison with previous investigations using continuous sulphasalazine, our study showed that the combination of 5-aminosalicylic tablets and enemas provided low relapse rates both at 6 and 12 months, suggesting a potential effectiveness in this form of treatment. Further studies are needed to confirm this result with controlled clinical trials.