Object grasping and manipulation in capuchin monkeys (genera Cebus and Sapajus)

The abilities to perform skilled hand movements and to manipulate objects dexterously are landmarks in the evolution of primates. The study of how primates use their hands to grasp and manipulate objects in accordance with their needs sheds light on how these species are physically and mentally equipped to deal with the problems they encounter in their daily life. We report data on capuchin monkeys, highly manipulative platyrrhine species that usually spend a great deal of time in active manipulation to search for food and to prepare it for ingestion. Our aim is to provide an overview of current knowledge on the ability of capuchins to grasp and manipulate objects, with a special focus on how these species express their cognitive potential through manual behaviour. Data on the ability of capuchins to move their hands and on the neural correlates sustaining their actions are reported, as are findings on the manipulative ability of capuchins to anticipate future actions and to relate objects to other objects and substrates. The manual behaviour of capuchins is considered in different domains, such as motor planning, extractive foraging and tool use, in both captive and natural settings. Anatomofunctional and behavioural similarities to and differences from other haplorrhine species regarding manual dexterity are also discussed

Rehabilitation Outcome Following Acute Stroke: Considering Ideomotor Apraxia

Stroke is a leading cause of death and the leading cause of adult disability in the United States affecting approximately 795,000 people yearly. Stroke sequelae often span multiple domains, including motor, cognitive, and sensory subsystems. Impairments can contribute to difficulty participating in activities of daily living (ADLs) and translate into disability - a concern for patients and occupational therapists alike. The role of ideomotor apraxia (IMA) in stroke rehabilitation is unclear. Thus, the purpose of these two studies is to investigate stroke rehabilitation outcome while considering the presence of ideomotor apraxia. Stroke causes dysfunctional movement patterns arising from an array of potential etiologies. Agreement exists that understanding the patient's functioning serves as the basis for the rehabilitation process and it is insufficient for clinicians simply to determine functional movement problems without knowing how underlying impairments contribute. Stroke-induced paresis is a prevalent impairment and frequent target of traditional rehabilitation. Stroke rehabilitation often addresses paresis narrowly with little consideration for other stroke consequences. Ideomotor apraxia is one such disorder after stroke that could conceivably limit rehabilitation benefit of otherwise efficacious treatment interventions aimed at remediating paresis. This led us to an initial study of a subject who experienced a single left, ischemic stroke with paresis of his right upper extremity and comorbid ideomotor apraxia. The subject participated in combined physical and mental practice for six consecutive weeks to improve use of his right arm. After intervention, the subject demonstrated clinically significant improvements in functional performance of his more-affected right upper extremity and reported greater self-perception of performance. The subject continued to demonstrate improvements after four weeks with no intervention and despite persistent IMA. This single case report highlights the importance of recognizing that ideomotor apraxia does present after stroke, and traditional stroke rehabilitation efforts directed at paresis can be efficacious for subjects with IMA. Traditional beliefs suggested that ideomotor apraxia does not translate to disability in everyday life and that IMA resolves spontaneously. Despite accumulating evidence of the influence of IMA on functional ability, this topic remains relatively neglected. It is unclear how ideomotor apraxia affects the rehabilitation process. The second study reports rehabilitation outcomes of a group of subjects following acute stroke. The Florida Apraxia Battery gesture-to-verbal command test was used to detect IMA in subjects. Level of independence with a set of ADLs and motor impairment of the more-affected upper extremity was documented at admission and discharge. Study subjects participated in standard of care stroke rehabilitation in the inpatient rehabilitation units. A total of fifteen subjects who sustained a left hemisphere stroke participated in this study - ten with IMA and five without IMA. After rehabilitation, subjects with IMA improved ADL independence and displayed decreased motor impairment of their right upper extremity. Subjects with and without IMA exhibited comparable improvements in ADL independence, but subjects with IMA exhibited less ADL independence upon when compared to subjects without IMA. Additional findings suggested that subjects with IMA were not different with respect to motor impairments and length of stay; however, additional studies with larger sample sizes are needed. In summary, these two studies aid to elucidate the implications of ideomotor apraxia on traditional stroke rehabilitation efforts. Study subjects with ideomotor apraxia after acute stroke still derive benefit from traditional rehabilitation. Because traditional rehabilitation interventions narrowly target motor impairment, these findings support the need for considering IMA as a factor in developing interventions tailored to patients with IMA and possibly as a specific focus for interventions. A step toward addressing this need is to assess whether IMA is present after stroke on a regular basis. This work provides a framework for researchers and clinicians to investigate further how ideomotor apraxia translates into disability. These findings are important since consideration of ideomotor apraxia could influence selection and design of rehabilitation interventions to optimize patient daily functioning after stroke

The role of morphology of the thumb in anthropomorphic grasping : a review

The unique musculoskeletal structure of the human hand brings in wider dexterous capabilities to grasp and manipulate a repertoire of objects than the non-human primates. It has been widely accepted that the orientation and the position of the thumb plays an important role in this characteristic behavior. There have been numerous attempts to develop anthropomorphic robotic hands with varying levels of success. Nevertheless, manipulation ability in those hands is to be ameliorated even though they can grasp objects successfully. An appropriate model of the thumb is important to manipulate the objects against the fingers and to maintain the stability. Modeling these complex interactions about the mechanical axes of the joints and how to incorporate these joints in robotic thumbs is a challenging task. This article presents a review of the biomechanics of the human thumb and the robotic thumb designs to identify opportunities for future anthropomorphic robotic hands

Neuromotor Control of the Hand During Smartphone Manipulation

The primary focus of this dissertation was to understand the motor control strategy used by our neuromuscular system for the multi-layered motor tasks involved during smartphone manipulation. To understand this control strategy, we recorded the kinematics and multi-muscle activation pattern of the right limb during smartphone manipulation, including grasping with/out tapping, movement conditions (MCOND), and arm heights. In the first study (chapter 2), we examined the neuromuscular control strategy of the upper limb during grasping with/out tapping executed with a smartphone by evaluating muscle-activation patterns of the upper limb during different movement conditions (MCOND). There was a change in muscle activity for MCOND and segments. We concluded that our neuromuscular system generates the motor strategy that would allow smartphone manipulation involving grasping and tapping while maintaining MCOND by generating continuous and distinct multi-muscle activation patterns in the upper limb muscles. In the second study (chapter 3), we examined the muscle activity of the upper limb when the smartphone was manipulated at two arm heights: shoulder and abdomen to understand the influence of the arm height on the neuromuscular control strategy of the upper limb. Some muscles showed a significant effect for ABD, while some muscle showed a significant effect for SHD. We concluded that the motor control strategy was influenced by the arm height as there were changes in the shoulder and elbow joint angles along with the muscular activity of the upper limb. Further, shoulder position helped in holding the head upright while abdomen reduced the moment arm and moment and ultimately, muscle loading compared to the shoulder. Overall, our neuromuscular system generates motor command by activating a multi-muscle activation pattern in the upper limb, which would be dependent upon the task demands such as grasping with/out tapping, MCOND, and arm heights. Similarly, our neuromuscular system does not appear to increase muscle activation when there is a combined effect of MCOND and arm heights. Instead, it utilizes a simple control strategy that would select an appropriate muscle and activate them based on the levels of MCOND and arm heights

Ground Robotic Hand Applications for the Space Program study (GRASP)

This document reports on a NASA-STDP effort to address research interests of the NASA Kennedy Space Center (KSC) through a study entitled, Ground Robotic-Hand Applications for the Space Program (GRASP). The primary objective of the GRASP study was to identify beneficial applications of specialized end-effectors and robotic hand devices for automating any ground operations which are performed at the Kennedy Space Center. Thus, operations for expendable vehicles, the Space Shuttle and its components, and all payloads were included in the study. Typical benefits of automating operations, or augmenting human operators performing physical tasks, include: reduced costs; enhanced safety and reliability; and reduced processing turnaround time

Advancing Medical Technology for Motor Impairment Rehabilitation: Tools, Protocols, and Devices

Excellent motor control skills are necessary to live a high-quality life. Activities such as walking, getting dressed, and feeding yourself may seem mundane, but injuries to the neuromuscular system can render these tasks difficult or even impossible to accomplish without assistance. Statistics indicate that well over 100 million people are affected by diseases or injuries, such as stroke, Parkinson’s Disease, Multiple Sclerosis, Cerebral Palsy, peripheral nerve injury, spinal cord injury, and amputation, that negatively impact their motor abilities. This wide array of injuries presents a challenge to the medical field as optimal treatment paradigms are often difficult to implement due to a lack of availability of appropriate assessment tools, the inability for people to access the appropriate medical centers for treatment, or altogether gaps in technology for treating the underlying impairments causing the disability. Addressing each of these challenges will improve the treatment of movement impairments, provide more customized and continuous treatment to a larger number of patients, and advance rehabilitative and assistive device technology. In my research, the key approach was to develop tools to assess and treat upper extremity movement impairment. In Chapter 2.1, I challenged a common biomechanical[GV1] modeling technique of the forearm. Comparing joint torque values through inverse dynamics simulation between two modeling platforms, I discovered that representing the forearm as a single cylindrical body was unable to capture the inertial parameters of a physiological forearm which is made up of two segments, the radius and ulna. I split the forearm segment into a proximal and distal segment, with the rationale being that the inertial parameters of the proximal segment could be tuned to those of the ulna and the inertial parameters of the distal segment could be tuned to those of the radius. Results showed a marked increase in joint torque calculation accuracy for those degrees of freedom that are affected by the inertial parameters of the radius and ulna. In Chapter 2.2, an inverse kinematic upper extremity model was developed for joint angle calculations from experimental motion capture data, with the rationale being that this would create an easy-to-use tool for clinicians and researchers to process their data. The results show accurate angle calculations when compared to algebraic solutions. Together, these chapters provide easy-to-use models and tools for processing movement assessment data. In Chapter 3.1, I developed a protocol to collect high-quality movement data in a virtual reality task that is used to assess hand function as part of a Box and Block Test. The goal of this chapter is to suggest a method to not only collect quality data in a research setting but can also be adapted for telehealth and at home movement assessment and rehabilitation. Results indicate that the data collected in this protocol are good and the virtual nature of this approach can make it a useful tool for continuous, data driven care in clinic or at home. In Chapter 3.2 I developed a high-density electromyography device for collecting motor unit action potentials of the arm. Traditional surface electromyography is limited by its ability to obtain signals from deep muscles and can also be time consuming to selectively place over appropriate muscles. With this high-density approach, muscle coverage is increased, placement time is decreased, and deep muscle activity can potentially be collected due to the high-density nature of the device[GV2] . Furthermore, the high-density electromyography device is built as a precursor to a high-density electromyography-electrical stimulation device for functional electrical stimulation. The customizable nature of the prototype in Chapter 3.2 allows for the implementation both recording and stimulating electrodes. Furthermore, signal results show that the electromyography data obtained from the device are of high quality and are correlated with gold standard surface electromyography sensors. One key factor in a device that can record and then stimulate based on the information from the recorded signals is an accurate movement intent decoder. High-quality movement decoders have been designed by closed-loop device controllers in the past, but they still struggle when the user interacts with objects of varying weight due to underlying alterations in muscle signals. In Chapter 4, I investigate this phenomenon by administering an experiment where participants perform a Box and Block Task with objects of 3 different weights, 0 kg, 0.02 kg, and 0.1 kg. Electromyography signals of the participants right arm were collected and co-contraction levels between antagonistic muscles were analyzed to uncover alterations in muscle forces and joint dynamics. Results indicated contraction differences between the conditions and also between movement stages (contraction levels before grabbing the block vs after touching the block) for each condition. This work builds a foundation for incorporating object weight estimates into closed-loop electromyography device movement decoders. Overall, we believe the chapters in this thesis provide a basis for increasing availability to movement assessment tools, increasing access to effective movement assessment and rehabilitation, and advance the medical device and technology field

Studio, progettazione e sviluppo di un sistema elettronico per la misura di segnali biometrici della mano finalizzato ad applicazioni riabilitative

In this Thesis the study and implementation of a transduction system for hand functional rehabilitation is described. The prototype is mainly constituted by a sensorized glove, a sensor driving circuitry and a visual feedback software interface. The prototype allows both to collect quantitative data and to analyze them, enabling an objective assessment of rehabilitative protocols effectiveness. The system was developed by the BioDevices Laboratory of the Department of Information Engineering of Padova University in collaboration with Wetware Concepts (University of Padova spin off) and the equipe of severe spinal/brain injured of San Bortolo hospital of Vicenz

Ipsi- and contralateral corticospinal influences in uni- and bimanual movements in humans

Il existe des projections corticospinales (CS) vers les motoneurones (MNs) aussi bien contra- (c) qu’ipsilatérales (i). Les influences CSc sur les MNs du poignet sont connues pour être modulées entre autres par la position du poignet et les afférences cutanées. Pour cette raison, notre objectif était de vérifier si ces caractéristiques sont aussi valides pour les influences CSi. En utilisant la stimulation transcrânienne magnétique au niveau du cortex primaire droit, nous avons tout d’abord comparé les influences CSi sur les MNs des fléchisseurs du poignet à des positions maintenues de flexion et d’extension durant une tâche uni-manuelle ainsi que deux tâches bimanuelles, ceci chez des sujets droitiers (n=23). Nous avons ensuite comparé les influences CSi dans cinq tâches bi-manuelles de tenue d’objet durant lesquelles les sujets avaient à tenir entre leurs mains un bloc à la surface soit lisse, soit rugueuse, dont le poids était supporté ou non, ceci en position de flexion (n=21). Dans une tâche, un poids était ajouté au bloc lisse en condition non supportée pour amplifier les forces de préhension requises. Une modulation positiondépendante était observée au niveau des potentiels évoqués moteurs (iPEM), mais seulement lors de la tâche bi-manuelle quand les deux mains interagissaient via un bloc (p= 0.01). Une modulation basée sur la texture était également présente, quel que soit le support de poids, et le bloc lisse était associé avec des iPEMs plus importants en comparaison avec le bloc rugueux (p= 0.001). Ainsi, les influences CSi sur les MNs n’étaient modulées que lors des tâches bi-manuelles et dépendaient de la manière dont les mains interagissaient. De plus, les afférences cutanées modulaient les influences CSi facilitatrices et pourraient ainsi participer à la prise en main des objets. Il en est conclu que les hémisphères droit et gauche coopèrent durant les tâches bimanuelles impliquant la tenue d’objet entre les mains, avec la participation potentielle de projections mono-, et poly-synaptiques, transcallosales inclues. La possibilité de la contribution de reflexes cutanés et d’étirement (spinaux et transcorticaux) est discutée sur la base de la notion que tout mouvement découle du contrôle indirect, de la « référence » (referent control). Ces résultats pourraient être essentiels à la compréhension du rôle des interactions interhémisphériques chez les sujets sains et cliniques.There are both contra- (c) and ipsilateral (i) corticospinal (CS) projections to motoneurons (MNs). There is evidence that cCS influences on wrist MNs are modulated by wrist position and cutaneous afferents. Thus, we aimed to test whether these findings are valid for iCS influences as well. Using transcranial magnetic stimulation applied over the right primary motor cortex, we first compared iCS influences on wrist flexor MNs at actively maintained flexion and extension wrist positions in one uni- and two bimanual tasks in right-handed subjects (n=23). We further compared iCS influences in five bimanual holding tasks in which subjects had to hold a smooth or coarse block between their hands, with or without its weight being supported, in flexion position (n=21). In one task, a weight was added to the unsupported smooth block to increase load forces. A position-dependent modulation of the short-latency motor evoked potential (iMEP) was observed, but only in the bimanual task when the two hands interacted through a block (p=0.01). A texture-dependent modulation was present regardless of the weight supported, and the smooth block was associated with larger iMEPs in comparison to the coarse block (p=0.001). Hence, iCS influences on MNs were modulated only in bimanual tasks and depended on how the two hands interacted. Furthermore, cutaneous afferents modulated facilitatory iCS influences and thus may participate to grip forces scaling and maintaining. It is concluded that the left and right cortices cooperate in bimanual tasks involving holding an object between the hands, with possible participation of mono- and poly-synaptic, including transcallosal projections to MNs. The possible involvement of spinal and trans-cortical stretch and cutaneous reflexes in bimanual tasks when holding an object is discussed based on the notion that indirect, referent control underlies motor actions. Results might be essential for the understanding of the role of intercortical interaction in healthy and neurological subjects