A novel approach to mechanical foot stimulation during human locomotion under body weight support.

Input from the foot plays an essential part in perceiving support surfaces and determining kinematic events in human walking. To simulate adequate tactile pressure inputs under body weight support (BWS) conditions that represent an effective form of locomotion training, we here developed a new method of phasic mechanical foot stimulation using light-weight pneumatic insoles placed inside the shoes (under the heel and metatarsus). To test the system, we asked healthy participants to walk on a treadmill with different levels of BWS. The pressure under the stimulated areas of the feet and subjective sensations were higher at high levels of BWS and when applied to the ball and toes rather than heels. Foot stimulation did not disturb significantly the normal motor pattern, and in all participants we evoked a reliable step-synchronized triggering of stimuli for each leg separately. This approach has been performed in a general framework looking for "afferent templates" of human locomotion that could be used for functional sensory stimulation. The proposed technique can be used to imitate or partially restore surrogate contact forces under body weight support conditions.

Experience at Italian National Institute of Health in the quality control in telemedicine: tools for gathering data information and quality assessing.

The authors proposed a set of tools and procedures to perform a Telemedicine Quality Control process (TM-QC) to be submitted to the telemedicine (TM) manufacturers. The proposed tools were: the Informative Questionnaire (InQu), the Classification Form (ClFo), the Technical File (TF), the Quality Assessment Checklist (QACL). The InQu served to acquire the information about the examined TM product/service; the ClFo allowed to classify a TM product/service as belonging to one application area of TM. The TF was intended as a technical dossier of product and forced the TM supplier to furnish the only requested documentation of its product, so to avoid redundant information. The QACL was a checklist of requirements, regarding all the essential aspects of the telemedical applications, that each TM products/services must be met. The final assessment of the TM product/service was carried out via the QACL, by computing the number of agreed requirements: on the basis of this computation, a Quality Level (QL) was assigned to the telemedical application. Seven levels were considered, ranging from the Basic Quality Level (QL1-B) to the Excellent Quality Level (QL7-E). The TM-QC process resulted a powerful tool to perform the quality control of the telemedical applications and should be a guidance to all the TM practitioners, from the manufacturers to the expert evaluators. The quality control process procedures proposed thus could be adopted in future as routine procedures and could be useful in the assessing the TM delivering into the National Health Service versus the traditional face to face healthcare services.

Experience at Italian National Institute of Health in the assessment of the quality in telemedicine: submission to a quality control process.

For applying a quality control of the telemedicine (TM) applications, in order to prevent device and/or service failure and to standardize some features of TM applications, a telemedicine quality control (TM-QC) process was proposed by authors. This TM-QC process was submitted to some TM manufacturers in order to assess their products/services and applied in two following phases, during which a set of procedures and tools were delivered to the TM suppliers. In the 1 degrees phase an Informative Questionnaire (InQu) and the Classification Form (ClFo) were delivered: the InQu gathered all the relevant information about the TM application in exam, the ClFo classified the TM product as belonging to one category (or application area) of TM. In the 2nd phase a Technical File (TF) and a Quality Assessment CheckList (QACL) were delivered: the TF was intended as a technical dossier of product; the QACL was a checklist of requirements that TM products must be agreed. The number of met requirements was computed and a Quality Level (QL), ranging from Basic Quality Level (QL1-B) to the Excellent Quality Level (QL7-E), was assigned to the examined TM products. The tested TM products presented in this paper, reached at least the minimum quality level (QL1-B). The TM-QC process allowed the definition of standardized quality levels for the TM products/services and the proposed procedures should be useful for promoting the using of standardized TM applications, so to speed up the integration process into the National Health Service.

Integration of monitoring and motor-training units for a tele-rehabilitation service.

A tele-rehabilitation system has been designed for general use. The service can extend the rehabilitation treatment of patients affected by neurological diseases such as stroke or multiple sclerosis to their home, while under the control, supervision and responsibility of a hospital. Part of the initial work involved identifying the functional blocks of a tele-rehabilitation service. There are three parties involved in the tele-rehabilitation service: the health provider (the central unit of the system), the health operator (the medical unit of the system, generally a therapist) and the home platform (a central console with a high level of modularity). Tele-rehabilitative services that are easy to use could radically change the routine care and rehabilitation process.

Quality assessment and cataloguing of telemedicine applications.

We created a Web catalogue of approved telemedicine systems that authoritative Italian research bodies had made available for more general use. The evaluation process was divided into two stages: (1) classification of the telemedicine systems and rough preliminary evaluation; (2) assessment of the telemedicine products and services. The scoring method was applied to four well-known telemedicine systems that had been tested in health-care settings: an echocardiology teleconsulting and analysis system; a ward nursing management system; a virtual cooperative system for the management of oncology patients and a telepathology system based on remotely controlled microscopy. After technical revision during the standardization/qualification process, the applications were transferred successfully to eight new health-care facilities. The methodology achieved the main goal of providing effective tools, such as a set of quality control procedures for telemedicine and telehealth projects and a Web catalogue of telemedicine applications with a standardized level of quality, available to all interested parties.

Does the thickening of Achilles tendon and plantar fascia contribute to the alteration of diabetic foot loading?

BACKGROUND: The diabetic foot often undergoes abnormal plantar pressures, changing in walking strategy, ulcerative processes. The present study focuses on the effects that diabetes-induced alterations of Achilles tendon, plantar fascia and first metatarso-phalangeal joint-both anatomical and functional-may have on foot loading. METHODS: Sixty-one diabetic patients, with or without neuropathy, and 21 healthy volunteers were recruited. Thickness of Achilles tendon and plantar fascia was measured by ultrasound. Flexion-extension of the first metatarso-phalangeal joint was measured passively. Main biomechanic parameters of foot-floor interaction during gait were acquired and related to the above measurements. FINDINGS: Plantar fascia and Achilles tendon were significantly (P<0.05) thicker in diabetics than in controls; mean values (SD) for controls, diabetics without and with neuropathy were 2.0 mm (0.5), 2.9 mm (1.2) and 3.0 mm (0.8) for plantar fascia, respectively, and 4.0 mm (0.5), 4.6 mm (1.0) and 4.9 mm (1.7) for Achilles tendon, respectively. Flexion-extension of the first metatarso-phalangeal joint was significantly (P<0.05) smaller in diabetics than in controls; mean values (SD) for controls, diabetics without and with neuropathy were 100.0 degrees (10.0), 54.0 degrees (29.4) and 54.9 degrees (17.2), respectively. The increase in the vertical force under the metatarsals was strongly related (R=0.83, explained variance=70.1%) to the changes in the three above parameters. INTERPRETATION: Thickening of plantar fascia and Achilles tendon in diabetics, more evident in the presence of neuropathy, concurs to develop a rigid foot, which poorly absorbs shock during landing (performs the physiological impact force absorption during landing). More generally, an overall alteration of the foot-ankle complex motion likely occurs throughout the whole gait cycle, which partly explains the abnormal loading under the forefoot.

Abnormal foot function in diabetic patients: the altered onset of Windlass mechanism.

AIM: The aim of this study was to examine foot function in the presence of diabetes-induced alterations of the anatomical and biomechanical unit formed by the Achilles tendon, plantar fascia and metatarso-phalangeal joints. More specifically, we focused on the Windlass mechanism, the physiological mechanism which entails stiffening of the foot during propulsion. METHODS: Sixty-one diabetic patients, with or without neuropathy, and 21 healthy volunteers were recruited. The thickness of Achilles tendon and plantar fascia was measured by ultrasound. The main biomechanical parameters of foot-floor interaction during gait were acquired by means of dedicated platforms. The range of motion of the 1st metatarso-phalangeal joint was measured passively. RESULTS: The plantar fascia (PF) and Achilles tendon (AT) were significantly thickened in diabetic patients [control subjects: PF 2.0+/-0.5 mm, AT 4.0+/-0.5 mm; diabetic patients without neuropathy: PF 2.9+/-1.2 mm (P=0.002), AT 4.6+/-1.0 mm (P=0.016); diabetic patients with neuropathy: PF 3.0+/-0.8 mm (P<0.0001), AT 4.9+/-1.7 mm (P=0.026)]. Joint mobility was significantly reduced [control subjects: 100.0+/-10.0 degrees; diabetic patients without neuropathy: 54.0+/-29.4 degrees (P<0.0001); diabetic patients with neuropathy: 54.9+/-17.2 degrees (P<0.0001)]. Loading times and force integrals under the heel and the metatarsals increased [metatarsal loading time (% stance phase): control subjects 88.2+/-4.1%; diabetic patients without neuropathy 90.1+/-4.7% (P=0.146); diabetic patients with neuropathy 91.7+/-6.6% (P=0.048)]. CONCLUSIONS: Increased thickness of Achilles tendon and plantar fascia, more evident in the presence of neuropathy, may contribute to an overall increase of tensile force and to the occurrence of an early Windlass mechanism, maintained throughout the whole gait cycle. This might play a significant role in the overall alteration of the biomechanics of the foot-ankle complex.

New instrumental set for the assessment of the hand functionality.

Hand motor deficits have been widely investigated, and several devices have been proposed for the selective and accurate study of specific hand motor tasks. Most studies have focused on the four, long fingers. The thumb function, although extremely important for the performance of most daily activities involving the hand, has scarcely been documented. A set of general-purpose, instrumental measuring devices has been designed and constructed at the authors' laboratory to measure and monitor the force each finger exerts separately, under isometric conditions, during pressing tasks. More generally, it is meant for the functional evaluation of the normal hand in different postures, but it also provides reliable measurements of the injured or deformed hand. The instrumental set is suitable for both biomechanical research and clinical applications. Effectively integrated with a visual feedback tool, it could be exploited in delivering and monitoring custom-designed rehabilitation programmes. The characteristics of the force transducers (range 0-100 N) were: inter-axis crosstalk < 4%; non-linearity < +/- 0.4% f.s.; hysteresis < 0.3% f.s.; overall accuracy +/- 1% f.s. The overall measurement system resolution was better than 0.1 N, and the keys response to the mechanical shock (acquired at 10 kHz) showed a resonance frequency of about 1 kHz. It was observed that the thumb contributed more than 30% of the overall pressing force.

Measurement device for ankle joint kinematic and dynamic characterisation.

The paper describes a measurement device for obtaining the kinematic characterisation and isometric loading of ankle joints under different working conditions. Non-invasive, in vivo experiments can be conducted with this experimental apparatus, the potential of which could be usefully exploited in basic biomedical research, prosthesis design, clinical applications, sports medicine and rehabilitation. The device determines the 3D movement of the foot with respect to the shank and evaluates the torques and moments around the three articular axes in relation to any desired angular position of the ankle complex. When integrated with superficial electromyographic techniques and electrical stimulation, it allows the assessment of the functionality of the lower leg in both mechanical and myo-electrical terms. The paper reports the main mechanical and electronic features of the device (high linearity; maximum moment ranges +/- 300 Nm for flexion-extension, +/- 35 Nm for both pronation-supination and internal-external rotation; angular ranges: +/- 100 degrees of dorsi-plantar flexion, +/- 50 degrees of internal-external rotation and prono-supination; linear ranges: +/- 25 mm along each axis). Results from a healthy volunteer, under voluntary or stimulated conditions, helped in testing its operatability, reliability, robustness, repeatability and effectiveness. Preliminary simplified protocols have been also applied to 20 healthy volunteers, and the main results were 80.8 +/- 11.9 degrees of internalexternal rotation, 46.2 +/- 9.1 degrees of prono-supination and 74.6 +/- 13.1 degrees of flexion-extension. Torques and moments were normalised with respect to a body mass index of 30. The maximum plantar flexion moment (57.5 + 21.3 Nm) was measured with the foot at 150 of dorsal flexion; the maximum dorsal flexion moment (50.2 + 20.3 Nm) was measured with the foot at 150 of plantar flexion.

Control of foot trajectory in human locomotion: role of ground contact forces in simulated reduced gravity.

We studied the changes of vertical contact forces, lower limb kinematics, and electromyographic activity (EMG) at different speeds and gravitational loads. To this end healthy subjects were asked to walk on a motorized treadmill while the percentage of body weight unloaded (body weight support, BWS) was modified in steps by means of a well-characterized unloading system. BWS was set at 0, 35, 50, 75, 95, or 100% of body weight. Walking speed was 0.7, 1.1, 2, 3, or 5 km/h. We found that changing BWS between 0 and 95% resulted in drastic changes of kinetic parameters but in limited changes of the kinematic coordination. In particular, the peak vertical contact forces decreased proportionally to BWS; at 95%-BWS they were 20-fold smaller than at 0% and were applied at the forefoot only. Also, there were considerable changes of the amplitude of EMG activity of all tested lower limb muscles and a complex re-organization of the pattern of activity of thigh muscles. By contrast, the corresponding variation of the parameters that describe shape and variability of the foot path was very limited, always <30% of the corresponding values at 0 BWS. Moreover, the planar co-variation of the elevation angles was obeyed at all speed and BWS values. Minimum variance of limb trajectory occurred at 3 km/h. At 100% BWS, subjects stepped in the air, their feet oscillating back and forth just above but never contacting the treadmill. In this case, step-to-step variability of foot path was much greater than at all other BWS levels but was restored to lower values when minimal surrogate contact forces were provided during the "stance" phase. The results did not depend on the specific instruction given to the subject. Therefore we conclude that minimal contact forces are sufficient for accurate foot trajectory control.

Pattern of abnormal tangential forces in the diabetic neuropathic foot.

OBJECTIVES: The role of tangential stress in neuropathic foot ulceration is yet unknown. The aim of this study was to investigate the tangential forces developed during gait by the whole foot and by selected subareas of it, namely the heel, the metatarsals and the hallux. METHODS: 61 diabetic patients have been evaluated: 27 without neuropathy, 19 with neuropathy and 15 with previous neuropathic ulcer. The patients were compared with 21 healthy volunteers. A piezo-dynamometric platform was used to measure the three components of the ground reaction force under the total foot and the selected subareas. RESULTS: A significant reduction was observed for the forward peak and the backward peak of the anteroposterior ground reaction force component measured under the whole foot. Patients with previous neuropathic ulcer showed a significant increase of the mediolateral stress under the metatarsals. CONCLUSIONS: Tangential stress is altered in diabetic neuropathic patients; the increased mediolateral component suggests that tangential stress could have a role in the high risk of recurrence observed in patients with previous ulceration. RELEVANCE: To assess the effectiveness of a non-invasive methodology for the estimation and the monitoring of significant alterations of the tangential stress with the increase of neuropathy.

Integrated pressure-force-kinematics measuring system for the characterisation of plantar foot loading during locomotion.

Plantar pressure, ground reaction force and body-segment kinematics measurements are largely used in gait analysis to characterise normal and abnormal function of the human foot. The combination of all these data together provides a more exhaustive, detailed and accurate view of foot loading during activities than traditional measurement systems alone do. A prototype system is presented that integrates a pressure platform, a force platform and a 3D anatomical tracking system to acquire combined information about foot function and loading. A stereophotogrammetric system and an anatomically based protocol for foot segment kinematics is included in a previously devised piezo-dynamometric system that combines pressure and force measurements. Experimental validation tests are carried out to check for both spatial and time synchronisation. Misalignment of the three systems is found to be within 6.0, 5.0 and 1.5 mm for the stereophotogrammetric system, force platform and pressure platform, respectively. The combination of position and pressure data allows for a more accurate selection of plantar foot subareas on the footprint. Measurements are also taken on five healthy volunteers during level walking to verify the feasibility of the overall experimental protocol. Four main subareas are defined and identified, and the relevant vertical and shear force data are computed. The integrated system is effective when there is a need for loading measurements in specific plantar foot subareas. This is attractive both in clinical assessment and in biomechanics research.

[Statistical bases and models for the selection of kidney transplant recipients]. / Basi statistiche e modelli per la scelta del ricevente del trapianto renale.

The thesis of this study is that the use of discrete simulations is the most appropriate instrument to support the definition of a kidney allocation procedure. We first furnished a general description of what it means to run a simulation to solve the problems related to the study of the statistical characteristics of any population. In the second part of the paper we mathematically formalized the subject of our study: the statistical properties of waiting lists, allocation algorithm and transplants. The third part reported the results of several simulations we have done with the aim to show the potential of these methods at assessing the most appropriate adjustments for the optimization of any allocation scheme.

[The national program of pediatric transplantation]. / Il programma nazionale di trapianto pediatrico.

The national programme for paediatric transplants currently implemented at the Istituto Superiore di Sanità is one of the first results of the efforts devoted to the definition of an efficient co-ordination policy of the transplantation activity in Italy. Since 1997 the programme has allowed all transplant centres throughout Italy to share unified waiting lists for kidney, heart, lung and liver, which gives paediatric patients a much better possibility than with local waiting lists. We present the regulations, criteria and operative solutions adopted to make the programme work, and the analysis of the data collected in these three years. The analysis gives statistical information on the composition and evolution of waiting lists and transplants done, which may be useful in the continuous process of revision and improvement of the criteria for recipient selection.

WARD: a pneumatic system for body weight relief in gait rehabilitation.

The paper presents Walking Assistance and Rehabilitation Device (WARD), a system for walking rehabilitation devised to relieve the patient of his/her body weight of a constant and prescribed amount by externally supporting the subject at the upper trunk and pelvis level by means of a harness. The system is based on a pneumatic actuator that has proved to be effective at maintaining a constant relief force. The constancy of this force that should be maintained even under high body weight support (BWS) conditions (70-80% of body weight) seems to be important for a correct motor pattern. A law has been identified that may be useful to adjust walking speed as a function of the prescribed BWS. WARD is simple to construct, practical to use, and has been characterized on healthy subjects.

Spatial-temporal parameters of gait: reference data and a statistical method for normality assessment.

Spatial and temporal parameters of gait are of recognised clinical relevance in the assessment of motor pathologies, because they normally occur in established combinations which can be altered by pathologies. The data collected from 596 healthy subjects have been used to establish relationships among these parameters and a procedure to estimate deviation from normality based on the comparison between measured values and values estimated by exploiting these relationships. The applied multiple linear regression method (MLRM) was preliminarily validated by comparing its outputs with those of corresponding equations found in the literature, and by applying it to a control group of 12 healthy subjects.

Ambulation training of neurological patients on the treadmill with a new Walking Assistance and Rehabilitation Device (WARD).

STUDY DESIGN: Patients with neurological walking impairment were rehabilitated with a new system, consisting of an apparatus to constantly relieve the body weight and a treadmill: The Walking Assistance and Rehabilitation Device (WARD). Patients were evaluated before and after rehabilitation with clinical scales and physiological measurements. OBJECTIVES: To evaluate the effectiveness of the WARD in improving walking capability in these patients. SETTING: The study was carried out in a clinical environment (IRCCS S. Lucia, Rehabilitation Hospital, Rome, Italy). METHODS: Seven patients (six with spinal cord injuries, one with brain injury) underwent a 1 - 2 month training period with the WARD. During the WARD training the body weight constant unloading (BWCU) applied to the patient through the WARD was regularly evaluated. Oxygen consumption, carbon dioxide production and heart rate were measured in order to obtain energy and cardiac costs of walking. These measurements were carried out while walking with the WARD at an appropriate treadmill speed (ATS) and in the open field at the most comfortable speed (MCS). All measurements, in addition to clinical scores related to the walking capability, were carried out at the beginning of the WARD training period (BWT) and at the end (EWT). At the EWT the patients were tested walking with the WARD observing the same BWT conditions (same ATS and BWCU), referred to as beginning conditions second measurements (BCSM). The relationships between physiological costs and ATS were described through second order polynomial regression curves and studied. RESULTS: Comparing the data obtained at the BWT and EWT, the following results were found significantly different: (1) Clinical scores improved; (2) All patients increased their ATS; (3) The BWCU was reduced; (4) The Walking Energy Cost (WEC) and the Walking Cardiac Cost (WCC) measured when walking with the WARD at the ATS improved in all patients; and (5) The WEC and WCC measured in the open field improved in all patients. The WEC vs ATS curve found at the EWT in the BCSM was found significantly different from the BWT curve, demonstrating a major improvement due to the WARD training. CONCLUSION: Despite some limitations due to sample size and functional ambulation scale, this study has demonstrated that the WARD training is effective in improving the walking capability and efficiency of the patients.

Alteration of spatial-temporal parameters of gait in Chronic Fatigue Syndrome patients.

Chronic Fatigue Syndrome (CFS) has been widely studied and a lot of information is available in the literature regarding the immunological, virological, neuroendocrinal and psychiatric aspects of the disease, but its aetiology is still poorly understood. Great attention has also been paid to the alteration of the muscular function caused by CFS. The aim of the present work was to study CFS patients' gait in order to find out objective measures which can better characterize the pathology. Spatial and temporal parameters of gait were collected from a group of 12 CFS informed volunteers by using the typical instrumentation of movement analysis, and raw data were statistically elaborated. Comparisons with reference data from a population of healthy subjects revealed significant abnormalities in the symmetry indices of the bilateral parameters and in the linear relationships among parameters, and between these parameters and the physical characteristics of the patients. Interestingly, the abnormalities were present as from the beginning of the gait, which indicates that they are unlikely to be caused by the rapid increasing fatigue. This strengthens the hypothesis of a direct involvement of the central nervous system (CNS) in the onset of the disease.

Piezo-dynamometric platform for a more complete analysis of foot-to-floor interaction.

A compound instrument was constructed by superimposing a dedicated pressure platform on a commercial force platform. This instrument simultaneously estimates the ground reaction force resultants (vertical and shear forces, free moment and location of the center of pressure), pressure distribution throughout the foot-floor contact area, the trajectory of the center of pressure superimposed on the contact area (footprint). On the basis of the readings provided by the force plate we calibrated pressure sensors more accurately. We could therefore accurately estimate the vertical local components of the ground reaction. This information and the measured shear force resultants were essential for computing the shear forces acting on elementary areas corresponding to the active surface of each pressure sensor. This, in turn, allowed us to estimate the vertical and shear force resultants and free moment for subareas of the foot. This is a feature peculiar to this compound instrument, and for its effective exploitation we have implemented a few methods for the reliable identification of the subareas of interest. Two application instances are hereby reported.