Dans les domaines de la réhabilitation, des sciences du sport et de l'ergonomie, l'évaluation des capacités de génération de force (CGF) peut aider à mieux comprendre les capacités motrices humaines. Le but de cette thèse a été d'évaluer les CGF du membre supérieur prédites au moyen de deux types de formalismes. Le premier provient du domaine de la robotique et a été utilisé pour déterminer l'ellipsoïde de force normalisé (EFN) et biomécanique (EFB), le polytope de force normalisé (PFN) et biomécanique (PFB). Pour une posture, ils sont calculés à partir d’un modèle polyarticulé du membre supérieur et de données sur les couples articulaires isométriques maximaux. Le second type fait appel à un modèle musculosquelettique afin de modéliser les CGF sous la forme d’un polytope de forces (PFMS). Tous ces modèles ont été comparés à un polytope de forces mesurées (PFM). Pour le construire, les forces maximales isométriques exercées par le membre supérieur au niveau de la main ont été évaluées dans vingt-six directions différentes. Enfin, le PFMS a été appliqué dans le cadre de la propulsion en fauteuil roulant afin de caractériser l'application des forces lors de cette tâche et un nouvel indice d’évaluation de la performance postural (IPP) a été proposé. / In fields like rehabilitation, sports sciences and ergonomics, the evaluation of the force feasible set (FFS) of the human limbs may help to better understand the human motor abilities. The aim of this thesis was to compare the upper-limb force capacity at the hand predicted by two different kinds of FFS formalism. The first one originating from the robotics field was used to compute the force ellipsoid (FE), scaled force ellipsoid (SFE), force polytope (FP) and scaled force polytope (SFP). For one posture, they are computed from the upper-limb model and hypotheses and data on maximum isometric joint torques. The second one permitted to compute the FFS modeled as a force polytope from a musculoskeletal model (MSFP). All the previously mentioned models were compared with a measured force polytope (MFP). To construct it, the maximum isometric forces exerted at the hand were assessed in twenty-six directions of the Cartesian space. Then, the MSFP was applied to the manual wheelchair propulsion in order to characterize the forces applied on the handrim during this task and a new evaluation index of postural performance (IPP) was also introduced.

Veterans with a spinal cord injury (SCI) engage in a complex and, often times, difficult dialogue within and through interactions in American society. That is, American society holds dear certain traditional values (ideals, beliefs, and customs) that promote the steady functioning and fabric of society. Through the process of enculturation and acculturation, likely, the majority of American citizens have already internalized many of these values. These values are cultural constructs of American society that can certainly influence and shape the myriad ways in which individual identity is formed. By identifying these value sets and analyzing the ways in which SCI veterans interact within society, I hope to achieve three goals; (1)discover the ways in which SCI veterans create and negotiate a unique sense of identity in American society, (2) illustrate the overall implications from this study to the general SCI population in America, and (3) provide a set of recommendations for healthcare providers for the purposes of creating and engaging in meaningful dialogues with SCI patients as well as aiding in more successful and sustainable health interventions.

<p>The problem with motorized wheelchairs is that they are large, clumsy and difficult to control. This is especially true if the driver has severely reduced capabilities. What we want is a wheelchair that can take instructionsfrom the driver and then based on its understanding of the environment, construct a plan that will take the user to the intended destination. The user should be able to sit in a room, tell the wheelchair that he wants to be in another room and the wheelchair should take him there as quickly and smoothly as possible. </p><p>The planner presented in this thesis uses a randomized bi-directional tree search. It builds two trees, one from the start state and one from the goal state by randomly sampling the control space of the robot. Each node is a state and each edge is a control input to the robot.</p><p>In order to decrease the execution time and improve path quality, the planner uses several heuristics to guide the planner. The heuristics are based on Rapidly-exploring Random Trees, Probabilistic Road-maps and the gradient method. </p><p>For a normal household situation, this planner can construct a decent plan in mere seconds on relatively slow hardware. Most times it finishes in a fraction of a second. </p><p>This means that the planner has the ability to run in real-time. As a consequence, the planner can handle a dynamic environment, inaccurate sensor readings and an inaccurate physical robot model.</p>

Purpose. To investigate the validity of the Sense Wear Pro Armband (SWA) to measure energy expenditure (EE) in healthy participants using wheelchair ergometry as an exercise modality. Method. Minute by minute EE was measured simultaneously using the SWA and indirect calorimetry(IC) during three different wheeling speeds including self-selected speed (0.81 m/s), moderate speed (1.11 m/s), and fast speed (1.73 m/s). Results. Twenty healthy volunteers (age = 34.0 (5.8) years)participated. The intraclass correlation coefficients (ICCs) were 0.50 (p=0.010), 0.59 (p=0.003), and 0.68 (p=0.000) for the self-selected speed, moderate speed, and fast speed wheeling, respectively. The SWA overestimated EE 57.8%, 57.4 %, and 63.7% for self-selected speed, moderate speed, and fast speed, respectively. Conclusions. The SWA failed to provide an accurate estimate of EE as measured by indirect calorimetry for wheelchair ergometry exercise in healthy subjects. The SWA overestimated EE for all exercise intensities. / REHABILITATION SCIENCE-PHYSICAL THERAPY

Uppskattningsvis 2000 personer lever med diagnosen tetraplegia i Sverige idag. Orsaken till skadan är trauma mot halskotpelaren som resulterar i total förlamning i bålen och de nedre extremiteterna. Ju högre upp skadan är placerad, desto större blir även förlamningen i de övre extremiteterna. Det traditionella sättet, att driva en manuell rullstol framåt med hjälp av drivringen, är med dessa funktionsbortfall, inte optimalt för att ta sig framåt eller över hinder. Ett prototyphjälpmedel, som förändrar rörelsemönstret till att större delen av kraften riktas i tangentiell riktigning framåt, med hjälp av de starkaste kvarvarande musklerna, utvecklades i projektet. Projektet har tillämpat dynamisk produktutveckling, med användarna i fokus, för att få fram en prototyp som uppfyller användarnas krav och som framförallt är användarvänlig. Detta har gjorts genom insamling av data under bland annat studiebesök, marknadsundersökningar och användarträffar. Prototypframtagningen skedde genom kontakt med näringslivet. Resultaten som kom fram vid användartesterna visade att prototypen kunde hjälpa till att öka maxkraften, för en av de två testpersonerna, som krävdes för att ta sig upp över en tröskel. Prototypen gav dock en upplevd försämring av manövreringsförmågan, då inte alla prototypens komponenter fungerad optimalt. Det krävs ytterligare tester och utvecklingsarbete innan produkten kan fungera i större utsträckning och för en större målgrupp. / An estimated 2000 people are today living in Sweden with a diagnosis of tetraplegi. The cause of the injury is trauma towards the cervical spine resulting in paralysis of the trunk as well as the lower limbs. The higher the positioning (i.e. the lower numbering of the vertebrae) of the cervical vertebrae damaged by the trauma, the more functions are lost in the upper extremities. When this happens, the traditional way of wheelchair propulsion with the push rim becomes less convenient. During the project, a prototype aid was developed. With the help of the aid, the users are able to change their pattern of movement when using the wheelchair. The new pattern allows the tetraplegi users to use their power in a tangential direction to the wheel. In addition they will be using mainly their strongest muscles in their arms, optimising their ability to move forward. In the project, dynamic product development was applied, focusing on the users in order to develop a user-friendly prototype which meets their requirements. To achieve this goal the project group collected data from people working with the rehabilitation of tetraplegics as well as people involved in the supply and distribution of rehabilitation aids. This benchmarking as well as meetings with intended users was helpful when gathering information. The prototype was developed with in close cooperation with various companies. User tests showed that the prototype could help increase maximum propulsive force required to climb over a threshold, for one of the two test persons. The prototype gave, however, a decrease in experienced maneuverability, as all of the components of the prototype were not working optimally. Further tests and development are needed before the product can operate for an extended use and for a wider target group.

The problem with motorized wheelchairs is that they are large, clumsy and difficult to control. This is especially true if the driver has severely reduced capabilities. What we want is a wheelchair that can take instructionsfrom the driver and then based on its understanding of the environment, construct a plan that will take the user to the intended destination. The user should be able to sit in a room, tell the wheelchair that he wants to be in another room and the wheelchair should take him there as quickly and smoothly as possible. The planner presented in this thesis uses a randomized bi-directional tree search. It builds two trees, one from the start state and one from the goal state by randomly sampling the control space of the robot. Each node is a state and each edge is a control input to the robot. In order to decrease the execution time and improve path quality, the planner uses several heuristics to guide the planner. The heuristics are based on Rapidly-exploring Random Trees, Probabilistic Road-maps and the gradient method. For a normal household situation, this planner can construct a decent plan in mere seconds on relatively slow hardware. Most times it finishes in a fraction of a second. This means that the planner has the ability to run in real-time. As a consequence, the planner can handle a dynamic environment, inaccurate sensor readings and an inaccurate physical robot model.

This thesis describes the research, design, and development of a mid-drive wheelchair for use by the elders living independently, in assisted living facilities, and in nursing homes created by a design team at Georgia Tech's Center for Assistive Technology and Environmental Access (CATEA). This wheelchair stands to significantly improve the mobility of elders through better drive wheel placement and design features that could stand to improve their quality of life.

Thesis (Ph.D.)--Ohio University, June, 2009. / Release of full electronic text on OhioLINK has been delayed until June 1, 2012. Includes bibliographical references (leaves 371-443)

Thesis (Ph.D.)--Ohio University, June, 2009. / Title from PDF t.p. Release of full electronic text on OhioLINK has been delayed until June 1, 2012. Includes bibliographical references (leaves 371-443)

The high demands of manual wheelchair propulsion put users at risk of additional pain and injury that can lead to further reductions in independence and quality of life. Seat position is an adjustable parameter that has been shown to influence propulsion biomechanics. As a result, a number of studies have attempted to optimize this position. However, due to complexities in quantifying upper extremity demand, seat position guidelines are often based on studies aimed at reducing indirect quantities (e.g., cadence, handrim forces, joint ranges of motion and muscle excitation levels) rather than more direct measures of demand (e.g., muscle stress and metabolic cost). Forward dynamics simulations provide an alternative approach to systematically investigate the influence of seat position on more direct measures of upper extremity demand. The objective of this study was to generate and analyze a set of forward dynamics simulations of wheelchair propulsion across the range of attainable seat positions to identify the optimal seat position that minimizes upper extremity demand (i.e., muscle stress, metabolic cost and muscle antagonism). The optimization results showed both metabolic cost and muscle stresses were near minimal values at superior/inferior positions corresponding to top dead center elbow angles between 110 and 120 degrees while at an anterior/posterior position with a hub-shoulder angle between 10 and 2.5 degrees. These minimal values coincided with a reduction in the level of antagonistic muscle activity, primarily at the glenohumeral joint. Seat positions that deviated from these minimal values increased the level of co-contraction required to maintain a stable, smooth propulsive stroke, and consequentially increased upper extremity demand. These results can provide guidelines for positioning the seat to help reduce upper extremity overuse injuries and pain, and thus improve the overall quality of life for wheelchair users. / text