Wearable Torso Exoskeletons for Human Load Carriage and Correction of Spinal Deformities

The human spine is an integral part of the human body. Its functions include mobilizing the torso, controlling postural stability, and transferring loads from upper body to lower body, all of which are essential for the activities of daily living. However, the many complex tasks of the spine leave it vulnerable to damage from a variety of sources. Prolonged walking with a heavy backpack can cause spinal injuries. Spinal diseases, such as scoliosis, can make the spine abnormally deform. Neurological disorders, such as cerebral palsy, can lead to a loss of torso control. External torso support has been used in these cases to mitigate the risk of spinal injuries, to halt the progression of spinal deformities, and to support the torso. However, current torso support designs are limited by rigid, passive, and non-sensorized structures. These limitations were the motivations for this work in developing the science for design of torso exoskeletons that can improve the effectiveness of current external torso support solutions. Central features to the design of these exoskeletons were the abilities to sense and actively control the motion of or the forces applied to the torso. Two applications of external torso support are the main focus in this study, backpack load carriage and correction of spine deformities. The goal was to develop torso exoskeletons for these two applications, evaluate their effectiveness, and exploit novel assistive and/or treatment paradigms. With regard to backpack load carriage, current torso support solutions are limited and do not provide any means to measure and/or adjust the load distribution between the shoulders and the pelvis, or to reduce dynamic loads induced by walking. Because of these limitations, determining the effects of modulating these loads between the shoulders and the pelvis has not been possible. Hence, the first scientific question that this work aims to address is What are the biomechanical and physiological effects of distributing the load and reducing the dynamic load of a backpack on human body during backpack load carriage? Concerning the correction of spinal deformities, the most common treatment is the use of a spine brace. This method has been shown to effectively slow down the progression of spinal deformity. However , a limitation in the effectiveness of this treatment is the lack of knowledge of the stiffness characteristics of the human torso. Previously, there has been no means to measure the stiffness of human torso. An improved understanding of this subject would directly affect treatment outcomes by better informing the appropriate external forces (or displacements) to apply in order to achieve the desired correction of the spine. Hence, the second scientific question that this work aims to address is How can we characterize three dimensional stiffness of the human torso for quantifiable assessment and targeted treatment of spinal deformities? In this work, a torso exoskeleton called the Wearable upper Body Suit (WEBS) was developed to address the first question. The WEBS distributes the backpack load between the shoulders and the pelvis, senses the vertical motion of the pelvis, and provides gait synchronized compensatory forces to reduce dynamic loads of a backpack during walking. It was hypothesized that during typical backpack load carriage, load distribution and dynamic load compensation reduce gait and postural adaptations, the user’s overall effort and metabolic cost. This hypothesis was supported by biomechanical and physiological measurements taken from twelve healthy male subjects while they walked on a treadmill with a 25 percent body weight backpack. In terms of load distribution and dynamic load compensation, the results showed reductions in gait and postural adaptations, muscle activity, vertical and braking ground reaction forces, and metabolic cost. Based on these results, it was concluded that the wearable upper body suit can potentially reduce the risk of musculoskeletal injuries and muscle fatigue associated with carrying heavy backpack loads, as well as reducing the metabolic cost of loaded walking. To address the second question, the Robotic Spine Exoskeleton (ROSE) was developed. The ROSE consists of two parallel robot platforms connected in series that can adjust to fit snugly at different levels of the human torso and dynamically modulate either the posture of the torso or the forces exerted on the torso. An experimental evaluation of the ROSE was performed with ten healthy male subjects that validated its efficacy in controlling three dimensional corrective forces exerted on the torso while providing flexibility for a wide range of torso motions. The feasibility of characterizing the three dimensional stiffness of the human torso was also validated using the ROSE. Based on these results, it was concluded that the ROSE may alleviate some of the limitations in current brace technology and treatment methods for spine deformities, and offer a means to explore new treatment approaches to potentially improve the therapeutic outcomes of the brace treatment

Developing a 3D multi-body simulation tool to study dynamic behaviour of human scoliosis

Ph.DDOCTOR OF PHILOSOPH

Robotic Exoskeletons for Torso Study, Training, and Assistance

Robotic exoskeletons are important tools in medicine for characterizing certain aspects of diseases, enabling physical therapy treatments, or providing assistance to those with impairments. One area in particular where these devices can make an impact is the study and treatment of scoliosis. First, I adapt a design of a robotic torso exoskeleton to serve the population most susceptible to scoliosis, female adolescents. I used the device to compare the torso stiffness of members of this group with and without scoliosis, and found an interaction effect of degree of freedom (DOF) and torso segment on translational stiffness, and an interaction effect of DOF and group on rotational stiffness. These results can inform the models used to create rigid orthoses for conservative treatment or to simulate the effects of surgical procedures. Second, I explore the effects of different types of augmented sensory feedback commonly used in scoliosis physical therapy. I compare visual and force feedback provided by the exoskeleton on one’s ability to replicate static poses and dynamic movements. I find that while force feedback leads to faster initial improvement, visual feedback may enable the user to learn finer details of the movement. Third, I design a torso exoskeleton for people with neuromotor impairments. People who are not able to sit up independently are at a high risk of developing neuromuscular scoliosis, and must balance the benefits of treatment with rigid orthoses, with the limits that these devices place on functional movements. The device allows users four degrees of freedom, to support functional movements such as reaching and pressure relief maneuvers, but prevents lateral translation and axial rotation, which can contribute to neuromuscular scoliosis. Together, these results demonstrate the potential for robotic exoskeletons in torso study, training, and assistance

Scoliosis treatment using spinal manipulation and the Pettibon Weighting System™: a summary of 3 atypical presentations

BACKGROUND: Given the relative lack of treatment options for mild to moderate scoliosis, when the Cobb angle measurements fall below the 25–30° range, conservative manual therapies for scoliosis treatment have been increasingly investigated in recent years. In this case series, we present 3 specific cases of scoliosis. CASE PRESENTATION: Patient presentation, examination, intervention and outcomes are detailed for each case. The types of scoliosis presented here are left thoracic, idiopathic scoliosis after Harrington rod instrumentation, and a left thoracic scoliosis secondary to Scheuermann's Kyphosis. Each case carries its own clinical significance, in relation to clinical presentation. The first patient presented for chiropractic treatment with a 35° thoracic dextroscoliosis 18 years following Harrington Rod instrumentation and fusion. The second patient presented with a 22° thoracic levoscoliosis and concomitant Scheuermann's Disease. Finally, the third case summarizes the treatment of a patient with a primary 37° idiopathic thoracic levoscoliosis. Each patient was treated with a novel active rehabilitation program for varying lengths of time, including spinal manipulation and a patented external head and body weighting system. Following a course of treatment, consisting of clinic and home care treatments, post-treatment radiographs and examinations were conducted. Improvement in symptoms and daily function was obtained in all 3 cases. Concerning Cobb angle measurements, there was an apparent reduction in Cobb angle of 13°, 8°, and 16° over a maximum of 12 weeks of treatment. CONCLUSION: Although mild to moderate reductions in Cobb angle measurements were achieved in these cases, these improvements may not be related to the symptomatic and functional improvements. The lack of a control also includes the possibility of a placebo effect. However, this study adds to the growing body of literature investigating methods by which mild to moderate cases of scoliosis can be treated conservatively. Further investigation is necessary to determine whether curve reduction and/or manipulation and/or placebo was responsible for the symptomatic and functional improvements noted in these cases

Biokinetic rehabilitation of scoliosis subjects

Of back problems experienced in adolescence, scoliosis is the most frequent (Bradford et al, 1987; Lancard-Dusek et al, 1991). Several studies have been conducted to determine the effect of exercise on back pain. The results indicated that certain regimes are more successful than others. The purpose of this study was to determine wether a corrective exercise programme, which was intensively and aggressively applied, will have a positive effect on adolescent scoliosis subjects. The subjects were divided, randomly, into a control and rehabilitation group. The rehabilitation group followed an eight week programme comprising 24 sessions. Both groups were evaluated at session zero (0) and session twenty four (24). A t-test for homogeneity was done at day zero, between the two groups for the variables V3 to V8. The results indicated homogeneity (P>0-05). A paired t-test was done for group one; indicating that there was a meaningful difference in all the variables; except for standing height (P>0*05). For group two the test indicates a meaningful difference for degrees, standing height and lateral flexion. A t-test at day 24 indicated a meaningful difference for degrees and lateral flexion. This indicates that the group which had followed the programme had improved whilst the control group had deteriorated. AFRIKAANS : Van die rug probleme ondervind by jeugdiges,, is skoliose die mees veelvuldig (Bradford et al, 1987; Lancas-Dusek et al, 1991). Verskeie studies is reeds gedoen wat die effek van oefening op die rug evalueer. Die resultate dui aan dat van die programme meer suksesvol is as ander. Die doel van die studie was om te bepaal of 'n korrektiewe oefenings program, wat intensief en aggresief toegepas is, 'n positiewe effek op geringe ado1essent skoliose individue sal hê. Die individue was willekeurig ingedeel in 'n kontrole en 'n rehabilitasie groep. Die rehabilitasie groep het 'n agt weke program gevolg van 24 sessies. Beide groepe was tydens sessie nul en sessie 24 ge-evalueer. 'n Toets vir homogeniteit was gedoen by dag nul, tussen die twee groepe, vir die veranderlikes V3 tat V8. Die resultate was homogeen (p>0-05). 'n Gepaarde t-toets vir groep een het aangedui dat daar 'n betekenisvolle verskil vir al die verander1ikes was; behalwe staande 1engte (p>0-05). Vir groep twee was daar 'n betekenisvolle verskil in grade, staande lengte en laterale fleksie. 'n T-toets op dag 24 het 'n betekenisvolle verskil vir laterale fleksie aangedui. Dit dui aan dat die groep wat die program gevolg het verbeter het, terwyl die kontrole groep agteruit gegaan het. CopyrightDissertation (MA (MHS))--University of Pretoria, 2011.Arts, Languages and Human Movement Studies Educationunrestricte