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Objective: To develop a satisfaction measure of activities and participation in the actual environment experienced by patients after chronic stroke using the Rasch measurement model., Methods: A 36-item questionnaire based on the International Classification of Functioning, Disability and Health model and existing scales was developed. The questionnaire was submitted to 101 patients (70% men; mean age 63 years) without major intellectual deficits who live in different types of residences (homes and nursing homes). The questionnaire was resubmitted after one month. The patients' responses were analysed separately using RUMM Rasch software to select items presenting an ordered rating scale, sharing the same discrimination, and fitting a unidimensional scale., Results: The final SATIS-Stroke scale consisted of 36 items rated by the patients. The patients reported perceptions over a wider range of measurement with high reliability (r = 0.94) and good reproducibility over time (intraclass correlation coefficient = 0.98). The SATIS-Stroke measures are significantly related to age and place of residence., Conclusion: SATIS-Stroke is a functional scale specifically developed to measure satisfaction with activities and participation, providing goal-setting guidelines for treatment planning. Its range and measurement precision are appropriate for clinical practice.

In many nonprimate species, rhythmic patterns of activity such as locomotion or respiration are generated by neural networks at the spinal level. These neural networks are called central pattern generators (CPGs). Under normal gravitational conditions, the energy efficiency and the robustness of human rhythmic movements are due to the ability of CPGs to drive the system at a pace close to its resonant frequency. This property can be compared with oscillators running at resonant frequency, for which the energy is optimally exchanged with the environment. However, the ability of the CPG to adapt the frequency of rhythmic movements to new gravitational conditions has never been studied. We show here that the frequency of a rhythmic movement of the upper limb is systematically influenced by the different gravitational conditions created in parabolic flight. The period of the arm movement is shortened with increasing gravity levels. In weightlessness, however, the period is more dependent on instructions given to the participants, suggesting a decreased influence of resonant frequency. Our results are in agreement with a computational model of a CPG coupled to a simple pendulum under the control of gravity. We demonstrate that the innate modulation of rhythmic movements by CPGs is highly flexible across gravitational contexts. This further supports the involvement of CPG mechanisms in the achievement of efficient rhythmic arm movements. Our contribution is of major interest for the study of human rhythmic activities, both in a normal Earth environment and during microgravity conditions in space.

Background/purpose: The mechanical properties of the fingertip skin are very important when studying dexterous manipulation. These properties are strongly influenced by the level of skin hydration. Currently, there is no device capable of measuring skin moisture during object manipulation., Methods: Skin moisture levels during object manipulation were measured using the Moisture Evaluator, a probe consisting of gold-covered electrodes connected to a resistor-capacitor circuit. In vivo calibration was performed by comparison with measurements obtained using a Corneometer at two normal force levels (0.2 and 2 N)., Results: Measurements from the Moisture Evaluator were well correlated with those from the Corneometer., Conclusion: A new device for evaluating skin moisture at the fingertip has been designed and validated.

Objective: To investigate the agreement between the self-reported and examiner-reported difficulties of patients with neuromuscular disorders (NMDs) in performing daily activities at home., Design: A comparison between 2 methods of administering a measurement instrument., Setting: Neuromuscular reference center in a university hospital., Participants: Adult patients (N=57) with diagnosed NMDs living at home., Interventions: Not applicable., Main Outcome Measure: The ACTIVLIM questionnaire., Results: The intraclass correlation coefficient, model 2,1 (ICC(2,1)), between the measures was very good (ICC(2,1)=.87), indicating a good agreement between self-perceived and observed measures., Conclusions: The use of ACTIVLIM as a self-reporting questionnaire is a valid method for assessing activity limitations in patients with NMD.

This paper investigates how the efficiency and robustness of a skilled rhythmic task compete against each other in the control of a bimanual movement. Human subjects juggled a puck in 2D through impacts with two metallic arms, requiring rhythmic bimanual actuation. The arms kinematics were only constrained by the position, velocity and time of impacts while the rest of the trajectory did not influence the movement of the puck. In order to expose the task robustness, we manipulated the task context in two distinct manners: the task tempo was assigned at four different values (hence manipulating the time available to plan and execute each impact movement individually); and vision was withdrawn during half of the trials (hence reducing the sensory inflows). We show that when the tempo was fast, the actuation was rhythmic (no pause in the trajectory) while at slow tempo, the actuation was discrete (with pause intervals between individual movements). Moreover, the withdrawal of visual information encouraged the rhythmic behavior at the four tested tempi. The discrete versus rhythmic behavior give different answers to the efficiency/robustness trade-off: discrete movements result in energy efficient movements, while rhythmic movements impact the puck with negative acceleration, a property preserving robustness. Moreover, we report that in all conditions the impact velocity of the arms was negatively correlated with the energy of the puck. This correlation tended to stabilize the task and was influenced by vision, revealing again different control strategies. In conclusion, this task involves different modes of control that balance efficiency and robustness, depending on the context.

Objective: To develop a questionnaire (ABILOCO), based on the Rasch measurement model, that can assess locomotion ability in adult stroke patients (International Classification of Functioning, Disability and Health activity domain)., Design: Prospective study and questionnaire development., Setting: A faculty hospital., Participants: Adult stroke patients (N=100) (age, 64+/-15y). The time since stroke ranged from 1 to 260 weeks., Intervention: A preliminary questionnaire included 43 items representing a large sample of locomotion activities. This questionnaire was tested on the 100 stroke patients, and their responses were analyzed using the Rasch model (RUMM 2020 software) to select items that had an ordered rating scale and fitted a unidimensional model., Main Outcome Measure: The ABILOCO questionnaire., Results: The retained items resulted in a 13-item questionnaire, which includes a wide range of locomotion abilities well targeted to the sample population, leading to good reliability (R=.93). The item calibration was independent of age, sex, time since stroke, and affected side. The concurrent validity of ABILOCO was also investigated by comparing it with well-known, criterion standard scales (Functional Walking Category, Functional Ambulation Categories, item 12 of the FIM instrument evaluating walking ability) and the walking speed measured with the 10-meter walk test., Conclusions: The ABILOCO questionnaire presents good psychometric qualities to measure locomotion ability in adult stroke patients. Its range and measurement precision make it attractive for clinical use throughout the rehabilitation process and for clinical research.

The present literature review on functional assessment in physiotherapy was carried out for the following reasons: 1) to identify the functional instruments used in the field of physiotherapy that were supported by published evidence of their psychometric qualities; 2) to investigate how these instruments relate to the International Classification of Functioning, Disability and Health (ICF); and 3) to investigate the use of functional instruments in the financing of physiotherapy. A search of Medline from 1990 to December 2005, in the domains of functional evaluation, psychometric qualities, functional classification, and health policy in relation to physiotherapy resulted in a list of 1,567 studies. Two reviewers examined the resulting references on the basis of their title and abstract, in order to select the studies that presented data on the psychometric qualities of functional evaluation tests, leading to a final selection of 44 such studies. A selection of functional tests was identified in four major diagnostic groups treated in community physiotherapy: musculoskeletal disorders (including lower back pain), stroke, the elderly, and traumatic brain injuries. The functional tests authors identified essentially cover the body and activities dimension of the ICF. The selected tests could be used as a basis for the standardisation of functional evaluation of the major diagnostic groups treated in community physiotherapy. This means that standards are available for reporting and following the evolution of patients both longitudinally and transversally. Nevertheless, in the current literature review no attempt at using functional outcomes as a rationale for financing physiotherapy could be found to date.

The purpose of this study was to investigate the validity of manual application of the grating orientation task (GOT), as currently used in fundamental and clinical research. Six examiners tested 12 subjects following recommendations of the literature. The results show that the normal force applied with the domes on the skin varied from one examiner to the next. Nevertheless, it did not affect the performance of the subjects, whose thresholds were consistent with those reported in the literature. This study highlights the inter-examiner reliability in the manual application of this test and validates this procedure.

Objective: Hand and upper limb involvement is common in patients with rheumatoid arthritis (RA). However, its impact on manual activities of daily life has not been fully evaluated. A measure of manual ability was developed, through the Rasch measurement model, by adapting and validating the ABILHAND questionnaire, which measures the patient's perceived difficulty in performing everyday manual activities., Methods: 112 patients with RA were evaluated. The following tests were performed: the ABILHAND questionnaire, the Health Assessment Questionnaire (HAQ), the Jamar grip and key pinch strength tests, the Box and Block dexterity test and the Purdue pegboard dexterity test. In total, 35 patients were reassessed to determine the test-retest reliability of the ABILHAND, and 6 patients were studied before and after therapy with tumour necrosis factor (TNF) blockers to address sensitivity to change., Results: The Rasch refinement of the ABILHAND led to a selection of 27 items rated on a 3-point scale. The resulting ability scale was targeted to the ability of the patients. The item-difficulty hierarchy was stable across demographic and clinical subgroups and over time. Grip and key pinch strength and manual and digital dexterity on both hands were significantly, though moderately, correlated with the ABILHAND measures. Manual ability was also significantly related to the number of affected hands, disease duration, tender and swollen joint counts on upper limbs, disease activity and the HAQ. Sensitivity to change was demonstrated in patients treated with TNF blockers, commensurate with their clinical improvement., Conclusion: The ABILHAND questionnaire is a clinically valid person-centred measure of manual ability that could be useful in longitudinal RA studies.

A common measure of activity limitations for both children and adults with neuromuscular disorders was developed using the Rasch model. A self-reported questionnaire containing daily activities was submitted to 245 adult patients and to the parents of 124 affected children from the two major Belgian communities. They were asked to provide their perceived difficulty in performing daily activities on a three-level scale. The 22 items of the final scale define a unidimensional and linear measure of activity limitations and show a continuous progression in their difficulty. The item difficulty hierarchy is invariant with regard to the diagnosis, community, gender and age. The scale exhibits a good precision, since the 22 items are well targeted on our sample (r=0.96); furthermore, it is reproducible over time (ICC=0.93). The patients' measures are related to the Functional Independence Measure motor score (rho=0.85), to the Brooke (rho=-0.63) grade and to the Vignos (rho=-0.83) grade.

Most common instruments used to assess the painfulness of nociceptive stimuli and the perception of such stimuli are ordinal. This property limits arithmetical operations and statistical procedures that can be applied on their numbers. The Rasch methodology provides mathematical procedures for transforming scores on an ordinal scale into measures on an interval scale. The present paper aims at presenting the basics of this methodology by applying it to the measurement of experimentally induced pain. Six blocks of seven CO(2) laser heat stimuli varying in intensity were delivered on the hand of 100 healthy subjects. They rated their pain perception on a three-level verbal rating scale (not painful, slightly painful, painful). One member of the family of Rasch models, the many-facet model, was applied to the analysis of these ratings. The analysis provided linear measures of the painfulness for each intensity of stimulation, of the pain perception of each subject and of the painfulness of each successive block. All these measures are located on a single pain perception continuum. Advantages and disadvantages of this methodology will be discussed in terms of subsequent possible mathematical analyses, statistical tests and implications for experimental and clinical investigations.

In humans, both clinical and functional imaging studies have evidenced the critical role played by the posterior parietal cortex, and particularly by the anterior intraparietal area (AIP), in skilled hand movements. However, the exact contribution of AIP to precision grasping remains debated. Here we used transcranial magnetic stimulation (TMS) to induce virtual lesions of the left and/or right AIP in subjects performing a grip-lift task with either hand. We found that, during movement preparation, a virtual lesion of AIP had distinct consequences on precision grasping of either hand depending on its time of occurrence: TMS applied 270-220 ms before the fingers contacted the manipulandum altered specifically the hand shaping, whereas lesions induced 170-120 ms before contact time only affected the grip force scaling. The lateralization of these two processes in AIP is also strikingly different: whereas a bilateral lesion of AIP was necessary to impair hand shaping, only a unilateral lesion of the left AIP altered the grip force scaling in either hand. The present study shows that, during movement preparation, AIP is responsible for processing two distinct, temporally dissociated, precision grasping parameters, regardless of the hand in use. This indicates that the contribution of AIP to hand movements is "effector-independent," a finding that may explain the invariance of grasping movements performed with either hand.

The precise contribution of the ipsilateral primary motor cortex (iM1) to hand movements remains controversial. To address this issue, we elicited transient virtual lesions of iM1 by means of transcranial magnetic stimulation (TMS) in healthy subjects performing either a grip-lift task or a step-tracking task with their right dominant hand. We found that, irrespective of the task, a virtual lesion of iM1 altered the timing of the muscle recruitment. In the grip-lift task, this led to a less coordinated sequence of grip and lift movements and in the step-tracking task, to a perturbation of the movement trajectory. In the step-tracking task, we have demonstrated that disrupting iM1 activity may, depending on the TMS delay, either advance or delay the muscle recruitment. The present study suggests that iM1 plays a critical role in hand movements by contributing to the setting of the muscle recruitment timing, most likely through either inhibitory or facilitatory transcallosal influences onto the contralateral M1 (cM1). iM1 would therefore contribute to shape precisely the muscular command originating from cM1.

The aim of this study was to determine age-related changes in tactile spatial resolution from 6 to 16 years old. Two hundred and twenty-two healthy children (105 boys and 117 girls) were assessed. The tactile spatial resolution threshold was determined using a classic set of JVP domes with a procedure adapted for children. Preadolescence appears to be an important step in tactile spatial resolution since children aged between 6 and 9 years old had a worse tactile spatial resolution than older children. Both peripheral and central explanations for this improvement of tactile spatial resolution with age are considered. The authors suggest that cortical maturational processes are likely to explain the better results of older children.

Small-object manipulation is essential in numerous human activities, although its neural bases are still essentially unknown. Recent functional imaging studies have shown that precision grasping activates a large bilateral frontoparietal network, including ventral (PMv) and dorsal (PMd) premotor areas. To dissociate the role of PMv and PMd in the control of hand and finger movements, we produced, by means of transcranial magnetic stimulation (TMS), transient virtual lesions of these two areas in both hemispheres, in healthy subjects performing a grip-lift task with their right, dominant hand. We found that a virtual lesion of PMv specifically impaired the grasping component of these movements: a lesion of either the left or right PMv altered the correct positioning of fingers on the object, a prerequisite for an efficient grasping, whereas lesioning the left, contralateral PMv disturbed the sequential recruitment of intrinsic hand muscles, all other movement parameters being unaffected by PMv lesions. Conversely, we found that a virtual lesion of the left PMd impaired the proper coupling between the grasping and lifting phases, as evidenced by the TMS-induced delay in the recruitment of proximal muscles responsible for the lifting phase; lesioning the right PMd failed to affect dominant hand movements. Finally, an analysis of the time course of these effects allowed us to demonstrate the sequential involvement of PMv and PMd in movement preparation. These results provide the first compelling evidence for a neuronal dissociation between the different phases of precision grasping in human premotor cortex.

Background Context: In adolescents with idiopathic scoliosis (AIS), several studies have shown that the pelvis is structurally changed by the spinal disorder. In fact, a significant correlation has been observed between the three-dimensional changes in the lumbar curve and the reduction in pelvic displacement in the three spatial planes during gait. However, the impact of this pelvic disorder on the walking mechanism has not been established., Purpose: To quantitatively evaluate the influence of scoliosis on the three-dimensional (3D) pelvic position during bipedal standing, on the 3D pelvic displacement during gait, and on the walking mechanics in adolescents with idiopathic lumbar and thoraco-lumbar scoliosis., Study Design/setting: Paired sample matched for age and gender., Patient Sample: Twenty-four subjects, 12 healthy adolescents matched for age and gender with 12 adolescents with lumbar or thoraco-lumbar idiopathic scoliosis., Outcome Measures: A test battery including clinical examination, radiological assessment, static 3D pelvic examination in bipedal position, and instrumented gait analysis. The statistical analysis was performed by a paired t test to evaluate the differences on nominally recorded data between control subjects and patients and a signed rank test for ordinal data., Methods: The spine and pelvis were assessed by X-ray, clinical examination, and 3D analysis with the Elite system V5, in the standing position. The gait was assessed by instrumented analysis, including synchronous kinematic, dynamic, and electromyographic (EMG) recordings., Results: Our results showed that radiological measurements of the pelvis were significantly different between patients and control subjects. However, 3D pelvic kinematics were not significantly different between AIS patients and normal subjects during standing and walking. We observed an increase in the muscular external work, a reduction in the efficiency of the locomotor mechanism, and a prolonged duration of activation of the lumbar muscles, ie, erector spinae and quadratum lumborum, in AIS patients., Conclusions: The scoliosis affected the structural bones of the pelvis with no effect on the 3D pelvis position during standing. During walking, normal 3D pelvic displacements could be explained by the prolonged duration of activation of the erector spinae and quadratum lumborum muscles bilaterally allowing the equilibrium of the pelvis to be maintained. This excessive muscular activity caused a failure of the locomotor mechanism as shown by an increase in the muscular external work.

In this experiment we examined the coupling between grip force and load force observed during cyclic vertical arm movements with a hand-held object, performed in different gravitational environments. Six subjects highly experienced in parabolic flight participated in this study. They had to continuously move a cylindrical object up and down in the different gravity fields (1g, 1.8 g and 0 g) induced by parabolic flights. The imposed movement frequency was 1 Hz, the object mass was either 200 or 400 g, the amplitude of movement was either 20 or 40 cm and an additional mass of 200 g could be wound around the forearm. Each subject performed the task during 15 consecutive parabolas. The coordination between the grip force normal to the surface and the tangential load force was examined in nine loading conditions. We observed that the same normal grip force was used for equivalent loads generated by changes of mass, gravity or acceleration despite the fact that these loads required different motor commands to move the arm. Moreover, our results suggest that the gravitational and inertial components of the load are treated adequately and independently by the internal models used to predictively control the required grip force. These results indicate that the forward internal models used to control precision grip take into account the dynamic characteristics of the upper limb, the object and the environment to predict the object's acceleration and, in turn, the load force acting at the fingertips.

The role played by sensory information in maintaining motor cortical representations is still incompletely understood. We investigated the effect of digital anaesthesia of the index finger and thumb on the amplitude of motor evoked potentials to transcranial magnetic stimulation (TMS) recorded from the first dorsal interosseus, F-wave response probability and maximal key pinch force. Whereas digital anaesthesia led to a 29% decrease in maximal force, both motor evoked potential amplitudes and F-wave probability remained unchanged. This dramatic decrease in maximal voluntary contraction following digital anaesthesia may result from a lack of proper sensory feedback during the task.

We conducted a prospective study to evaluate the functional status of patients surgically treated by trapeziectomy with intermetacarpal tendon stabilisation. Pain relief, the height of the trapezial cavity, hand impairment, and manual ability were measured in a group of 18 patients at a mean of 2.3 years after surgery. Complete relief of pain was achieved in 89% of our patients. The height of the trapezial cavity was significantly reduced. Hand strength and digital dexterity were not impaired after the operation. Manual ability was significantly improved by the trapeziectomy as demonstrated by the median VAS values of 53.5 before and 95.5 after surgery. The ABILHAND questionnaire revealed that most of the patients were satisfied with the functional results of the trapeziectomy. Based on our findings in this prospective study, it appears that trapeziectomy with intermetacarpal tendon stabilisation relieved pain in almost 90% of patients suffering from trapeziometacarpal osteoarthritis, at no functional cost.

Only after injury, or perhaps prolonged exposure to cold that is sufficient to numb the fingers, do we suddenly appreciate the complex neural mechanisms that underlie our effortless dexterity in manipulating objects. The nervous system is capable of adapting grip forces to a wide range of object shapes, weights and frictional properties, to provide optimal and secure handling in a variety of potentially perturbing environments. The dynamic interplay between sensory information and motor commands provides the basis for this flexibility, and recent studies supply somewhat unexpected evidence of the essential role played by cutaneous feedback in maintaining and acquiring predictive grip force control. These examples also offer new insights into the adaptive control of other voluntary movements.

Objective: To develop a clinical tool for measuring manual ability (ABILHAND-Kids) in children with cerebral palsy (CP) using the Rasch measurement model., Methods: The authors developed a 74-item questionnaire based on existing scales and experts' advice. The questionnaire was submitted to 113 children with CP (59% boys; mean age, 10 years) without major intellectual deficits (IQ > 60) and to their parents, and resubmitted to both groups after 1 month. The children's and parents' responses were analyzed separately with the WINSTEPS Rasch software to select items presenting an ordered rating scale, sharing the same discrimination, and fitting a unidimensional scale., Results: The final ABILHAND-Kids scale consisted of 21 mostly bimanual items rated by the parents. The parents reported a finer perception of their children's ability than the children themselves, leading to a wider range of measurement, a higher reliability (R = 0.94), and a good reproducibility over time (R = 0.91). The item difficulty hierarchy was consistent between the parents and the experts. The ABILHAND-kids measures are significantly related to school education, type of CP, and gross motor function., Conclusions: ABILHAND-Kids is a functional scale specifically developed to measure manual ability in children with CP providing guidelines for goal setting in treatment planning. Its range and measurement precision are appropriate for clinical practice.

Introduction: In Europe it is common for outcome measures to be translated for use in other languages. This adaptation may be complicated by culturally specific approaches to certain tasks; for example, bathing. In this context the issue of cross-cultural validity becomes paramount., Objective: To facilitate the pooling of data in international studies, a project set out to evaluate the cross-cultural validity of impairment and activity limitation measures used in rehabilitation from the perspective of the Rasch measurement model., Methods: Cross-cultural validity is assessed through an analysis of Differential Item Functioning (DIF) within the context of additive conjoint measurement expressed through the Rasch model. Data from patients undergoing rehabilitation for stroke was provided from 62 centers across Europe. Two commonly used outcome measures, the Mini-Mental State Examination (MMSE) and the Functional Independence Measure (FIM) motor scale are used to illustrate the approach., Results: Pooled data from 3 countries for the MMSE were shown to fit the Rasch model with only 1 item displaying DIF by country. In contrast, many items from the FIM expressed DIF and misfit to the model. Consequently they were allowed to be unique across countries, so resolving the lack of fit to the model., Conclusions: Where data are to be pooled for international studies, analysis of DIF by culture is essential. Where DIF is observed, adjustments can be made to allow for cultural differences in outcome measurement.

Using functional magnetic resonance imaging, the brain activation related to unilateral sequential finger-to-thumb opposition was studied in six children with a right congenital hemiplegia of cortical origin. They were compared to six age-matched controls. In the control group, movements with either hand asymmetrically activated the sensorimotor cortex and premotor areas in both cerebral hemispheres with a typical contralateral predominance. By contrast, paretic finger movements activated both hemispheres in the hemiplegic patients, with a strong ipsilateral predominance favoring the undamaged hemisphere. The activation induced by nonparetic finger movements was restricted to the contralateral undamaged hemisphere. Furthermore, the level of activation in the undamaged cortex was partly related to residual finger dexterity, according to covariance analysis. These activation patterns indicate an adaptive reorganization of the cortical motor networks in this group of patients, with a prominent involvement of the undamaged hemisphere in the control of finger movements with either hand.

This article is a brief review of the outcome evaluation of the hand and wrist according to the International Classification of Functioning, Disability, and Health. Several tools currently exist to quantify outcome in hand surgery at the impairment level (eg, mobility, hand strength, cutaneous sensation, dexterity). According to the World Health Organization's paradigm, however, activity limitations and participation restrictions are also clinically relevant. The authors have recently built a measure of an upper limb-impaired individual's ability to manage manual activities in daily life. Participation and quality of life are difficult outcomes to measure because they are multidimensional and depend on such factors as functional abilities, general physical health, financial security, and stability of the social and familial environment.

One of the most devastating consequences of early corticospinal lesions is the impaired dexterity that results in a noticeable deficit while manipulating small objects. One purpose of the present study was to investigate the extent to which a deficit in the coordination of fingertip forces when grasping and lifting an object between the thumb and index finger could account for the impaired dexterity in patients with congenital hemiplegia (CH). A second objective was to examine whether, in these patients, deficits in skilled hand movements are correlated with the importance of structural damage to the corticospinal tract. The scaling and coordination of fingertip forces during precision grip was investigated in 16 CH patients (aged 8-19 years) and 16 age- and sex-matched control subjects. Proprioception, stereognosis, pressure sensitivity and motor upper limb function (including digital and manual dexterity) were also assessed quantitatively. The structural damage of the corticospinal tract was estimated by measuring the cross-sectional area of cerebral peduncles with MRI and by calculating an index of symmetry between the two peduncles. In CH patients, a large number of parameters measured during the grip-lift task were significantly different when compared with those found in control subjects. Among those, the duration of the preloading and loading phases was significantly longer in CH patients. In addition, both the dissimilarity and time-shift between the profiles of the grip and load force rates, quantified with the cross-correlation method, were also significantly larger in CH patients; the time-shift was strongly correlated with impaired dexterity. These findings suggest that impaired dextrous finger movements in CH patients may specifically result from their inability to ensure a precise synergy between fingertip forces while manipulating an object. Finally, the finding that the time-shift also correlated with the corticospinal tract dysgenesis, as estimated with the cerebral peduncle asymmetry, argues in favour of a critical role of the corticospinal system in the temporal coordination between different muscles involved in dextrous hand movements. Both digital and manual dexterity were also altered in the non-paretic hand of CH patients. This deficit may reveal the contribution of the lesioned hemisphere to the control of ipsilateral skilled finger movements.

Investigating cyclic vertical arm movements with an instrumented hand-held load in an airplane undergoing parabolic flight profiles allowed us to determine how humans modulate their grip force when the gravitational and the inertial components of the load force are varied independently. Eight subjects participated in this study; four had already experienced parabolic flights and four had not. The subjects were asked to move the load up and down continuously at three different gravitational conditions (1 g, 1.8 g, and 0 g). At 1 g, the grip force precisely anticipated the fluctuations in the load force, which was maximum at the bottom of the object trajectory and minimum at the top. When gravity changed, the temporal coupling between grip force and load force persisted for all subjects from the first parabola. At 0 g, the grip force was accurately adjusted to the two load force peaks occurring at the two opposite extremes of the trajectory due to the absence of weight. While the experienced subjects exerted a grip force appropriate to a new combination of weight and inertia since their first trial, the inexperienced subjects dramatically increased their grip when faced with either high or low force levels for the first time. Then they progressively released their grip until a continuous grip-load force relationship with regard to 1 g was established after the fifth parabola. We suggest that a central representation of the new gravitational field was rapidly acquired through the incoming vestibular and somatic sensory information.

Previous research has shown that grip and load forces are modulated simultaneously during manipulation of a hand-held object. This close temporal coupling suggested that both forces are controlled by an internal model within the CNS that predicts the changes in tangential force on the fingers. The objective of the present study was to examine how the internal model would compensate for the loss of cutaneous sensation through local anesthesia of the index and thumb. Ten healthy adult subjects (5 men and 5 women aged 20-57 yr) were asked to grasp, lift, and hold stationary, a 250 g object for 20 s. Next, the subjects were asked to perform vertical oscillatory movements over a distance of 20 cm at a rate of 1.0 Hz for 30 s. Eleven trials were performed with intact sensation, and 11 trials after a local ring-block anesthesia of the index and thumb with bupivacain (5 mg/ml). During static holding, loss of cutaneous sensation produced a significant increase in the safety margin. However, the grip force declined significantly over the 20-s static hold period. During oscillatory arm movements, grip and load forces were continuously modulated together in a predictive manner as suggested by Flanagan and Wing. Again, the grip force declined over the 30-s movement, and 7/10 subjects dropped the object at least once. With intact sensation, the object was never dropped; but with the fingers anesthetized, it was dropped on 36% of the trials, and a significant slip occurred on a further 12%. The mean correlation between the grip and load forces for all subjects deteriorated from 0.71 with intact sensation to 0.48 after digital anesthesia. However, a cross-correlation calculated between the grip and load forces indicated that the phase lag was approximately zero both with and without digital anesthesia. Taken together, the data from the present study suggest that cutaneous afferents are required for setting and maintaining the background level of the grip force in addition to their phasic slip-detection function and their role in adapting the grip force/load force ratio to the friction on initial contact with an object. Finally, at a more theoretical level, they correct and maintain an internal model of the physical properties of hand-held objects.

Brain plasticity was investigated in a child with a hemiplegia due to unilateral schizencephaly involving the sensorimotor cortex. This focal lesion led to a dramatic functional reorganization of the undamaged hemisphere, as evidenced by the unusual pattern of fMRI activation during paretic finger movements. The functional relevance of the activation in the undamaged motor cortex was supported by the finding that TMS of this area yielded a response in the paretic hand, indicating that it controls both hands. However, this reorganization was not restricted to the primary motor cortex, but also concerned other structures involved in the control of movements, as shown by the activation of contralesional SMA and thalamus. In contrast, the fMRI activation in the damaged sensorimotor cortex during paretic hand movements appears functionally irrelevant., (Copyright 2002 Lippincott Williams & Wilkins)

The objective of this study was to measure the forces applied on an object manipulated in different gravitational fields attained during parabolic flights. Eight subjects participated flights (ES) and four were inexperienced (NES). They had to move continuously an instrumented object up and down in three different gravitational conditions (1 g, 1.8 g, 0 g). In 1 g, the grip force precisely anticipated the fluctuations of load force which was maximum and minimum at the bottom and at the top of the arm trajectory respectively. When the gravity changed (0 g and 1.8 g), the grip-load force coupling persisted for all the subjects from the first parabola. While the ES immediately exerted a grip force appropriate to the gravity, the NES dramatically increased their grip when faced with hyper and microgravity for the first time. Then, they progressively released their grip until a continuous grip-load force relationship with regard to 1 g was established after the fifth parabola. We suggest that each new gravitational field is rapidly incorporated into an internal model within the CNS which can then be reused as required by the occasion.

The aim of the study was to survey the use of outcome measures in rehabilitation within Europe. It was envisaged that this would provide the basis for further studies on the cross-cultural validity of outcome measures. A postal questionnaire was distributed in November 1998 to 866 units providing rehabilitation. In total, 418 questionnaires were returned, corresponding to a response rate of 48%. These 418 centres treated an estimated 113,000 patients annually, undertaking 360,000 assessments. The survey focused on nine diagnostic groups: hip and knee replacement, low back pain, lower limb amputees, multiple sclerosis, neuromuscular disorders, rheumatoid arthritis, spinal cord lesions, stroke and traumatic brain injury. It identified a relatively small number of dominant outcome assessments for each diagnostic group and some variation in the preference for measures across regions. A large number of measures, however, are being used in one or a small number of locations and with relatively few patients. For rehabilitation of orthopaedic patients the majority of assessments undertaken are at the impairment level. For patients with neurological disorders the emphasis is mostly upon measures of disability.

Background and Purpose: Chronic hemiparetic patients often retain the ability to manage activities requiring both hands, either through the use of the affected arm or compensation with the unaffected limb. A measure of this overall ability was developed by adapting and validating the ABILHAND questionnaire through the Rasch measurement model. ABILHAND measures the patient's perceived difficulty in performing everyday manual activities., Methods: One hundred three chronic (>6 months) stroke outpatients (62% men; mean age, 63 years) were assessed (74 in Belgium, 29 in Italy). They lived at home and walked independently and were screened for the absence of major cognitive deficits (dementia, aphasia, hemineglect). The patients were administered the ABILHAND questionnaire, the Brunnström upper limb motricity test, the box-and-block manual dexterity test, the Semmes-Weinstein tactile sensation test, and the Geriatric Depression Scale. The brain lesion type and site were recorded. ABILHAND results were analyzed with the use of Winsteps Rasch software., Results: The Rasch refinement of ABILHAND led to a change from the original unimanual and bimanual 56-item, 4-level scale to a bimanual 23-item, 3-level scale. The resulting ability scale had sufficient sensitivity to be clinically useful. Rasch reliability was 0.90, and the item-difficulty hierarchy was stable across demographic and clinical subgroups. Grip strength, motricity, dexterity, and depression were significantly correlated with the ABILHAND measures., Conclusions: The ABILHAND questionnaire results in a valid person-centered measure of manual ability in everyday activities. The stability of the item-difficulty hierarchy across different patient classes further supports the clinical application of the scale.

A patient with unilateral, painless, chronic progressive upper limb sensorimotor deficit showed electrophysiological evidence of a focal demyelinating neuropathy with almost complete conduction block across the brachial plexus. Magnetic resonance imaging disclosed marked brachial plexus hypertrophy. Intravenous immunoglobulin led to fast and complete recovery, maintained by intermittent perfusions. Hypertrophic brachial plexus neuropathy can be a presentation of focal chronic inflammatory demyelinating polyradiculoneuropathy. Objective and quantitative assessment of hand function is useful to evaluate treatment results and to optimize treatment regimens., (Copyright 2000 John Wiley & Sons, Inc.)

Seven subjects were asked to reach and grasp an object between the thumb and index finger, lift it about 30 cm high and 25 cm forward from one table to another, at their preferred speed. The perpendicular grip force and the tangential load force applied to the contact surface were digitized at 500 Hz and stored on a laboratory computer. The trajectory of the wrist and of the object was recorded using four infrared cameras tracking the movement of reflective markers attached to the distal styloid process of the radius and on the top of the object. The aim of this study was to demonstrate the influence of low friction (i.e. surface slipperiness) on the acceleration of the wrist. Friction was reduced by coating the smooth brass grasping surface with talc. The seven subjects had skin to surface coefficients of friction which ranged from 0.52-1.18 for dry brass and 0.24 0.34 for talc-coated brass. Two weights (418 and 1070 g) were used with each surface. The results indicated that with the slippery surface the necessary higher grip force/load force ratio was produced by an increase in the grip force and by a decrease in the wrist acceleration and a consequent reduction in the load force. This strategy was observed for both weights over a range of grip strengths between 21-98% of the individual's maximum voluntary contraction (MVC). This implies that even with adequate grip force reserves the reduction in acceleration is an acceptable and probable alternative solution to the force control problem. Our results also suggested that the loading rate and the object acceleration were planned and controlled together which emphasizes the role played by a predictive mechanism in organizing the kinematics of movements involving hand-held objects. This study shows that friction of the grasping surface not only affects the prehensile force dynamics, but it also influences the kinematics of the entire upper limb.

The purpose of this study was to evaluate the long-term effectiveness of wrist fusion on the relief of pain and also the functional capacities of the upper limbs in patients with rheumatoid arthritis (RA). Eighteen patients were assessed at a mean of 7 years after wrist arthrodesis and a mean of 17 years after the onset of RA. Radiological measurements, pain assessment and impairment rating of the upper limbs were made of the fused and non-fused sides. The average position of arthrodesis was 8 degrees of extension and 9 degrees of ulnar deviation. All patients were pleased with the procedure and had satisfactory pain relief. Impairment ratings did not detect any significant difference in the sensory and motor function of the hand when the fused and non-fused groups were compared. We conclude that in patients with rheumatoid arthritis, wrist arthrodesis is a reliable procedure that provides predictable pain relief and a high degree of satisfaction without additional functional loss in the upper limb.

Objective: To apply the Rasch measurement model to the development of a clinical tool for measuring manual (dis)ability (ABILHAND)., Design: Manual ability was evaluated in terms of the difficulty perceived by a hand-impaired patient on 57 representative unimanual or bimanual activities., Setting: A clinical laboratory., Patients: Eighteen rheumatoid arthritis patients (14 women, 4 men) were interviewed after wrist arthrodesis (10 right, 4 left, and 4 both wrists). Their ages ranged from 38 to 77 years, time since diagnosis ranged from 7 to 41 years, and time since surgery ranged from 0.5 to 17 years., Main Outcome Measure: ABILHAND, administered at a mean duration of 7 years after arthrodesis., Results: Forty-six of the 57 items define a common, single manual ability continuum with widespread measurement range and regular item distribution. Items relating to feeding, grooming, and dressing upper body worked consistently with their counterparts in other disability scales. More difficult items extend the measurement range beyond that of most existing manual ability scales., Conclusion: Even in a small sample of patients, using the Rasch methodology enabled the investigators to produce a useful scale of manual (dis)ability and to define manual ability as a unique construct, at least in patients with rheumatoid arthritis.

A 60-year-old man presented with progressive large fiber sensory loss in the right first three fingers and, to a lesser extent, in both fourth and fifth fingers. Electrophysiologic studies were characteristic of chronic sensory demyelinating polyneuropathy, a variant of chronic inflammatory demyelinating polyneuropathy. Plasma exchange was unsuccessful, but intravenous immunoglobulin (IVIG) led to complete recovery of sensation for 2 months, although neurophysiologic abnormalities persisted. A battery of noninvasive tests to measure hand grip strength, tactile sensation at the fingertips, and motor control of prehension during precision grip revealed marked abnormalities in the right hand before IVIG. One month after IVIG, all test results had normalized, but they returned to pretreatment levels after 3 months. Functional evaluation of the hand may be a sensitive method to objectively quantify loss of and changes in cutaneous mechanoreceptor function of the fingers in large fiber sensory neuropathy.

Objectives: The present study investigated whether the impairment of tactile sensitivity after exposure to vibration disturbs the motor control of precision handling and, if so, whether it can result in an increased risk of injury during or after tasks involving the use of vibrating tools., Methods: Twelve men were manually exposed to vibration from an electric sander for 30 min. Cutaneous sensitivity was quantified to measuring the pressure perception threshold and vibration perception threshold (125 Hz) on the pulp of the second finger. Manipulative skill was evaluated by grip-lift movements and the Purdue pegboard test., Results: The vibration perception threshold increased very significantly from 94.0 dB (0.06 m/s2) before the vibration exposure to 127.5 dB (3.2 m/s2) immediately after the exposure. The pressure perception threshold tended to increase after vibration exposure, although not significantly, but manipulative skill was not altered., Conclusions: Change in vibration perception threshold was not associated with a significant increase in the pressure perception threshold or a perturbation of manual skill. Therefore, in conditions similar to those of our experiment, the safety of a precision task does not appear to be reduced after such vibration exposure.