Design and fabrication of an Intuitive Leg Assist Device to address lower extremity weakness

2011 ◽  
Author(s):  
B. Shah ◽  
D. McNally ◽  
K. Patel ◽  
S. Frone ◽  
S. Sutaria
Keyword(s):  
Lower Extremity ◽  
Assist Device ◽  
Lower Extremity Weakness

scholarly journals Exo-Leg: An Active Single-Leg External Walking Assist Device

2010 ◽  
Vol 4 (2) ◽  
Author(s):  
Thomas Coughlin ◽  
Jessica L. Knight ◽  
Alex Hinkle ◽  
Matt Van Cleve ◽  
Salam Al-Omaishi ◽  
...  
Keyword(s):  
Lower Extremity ◽  
Pressure Sensors ◽  
Trigger Points ◽  
Simulation Software ◽  
Foot Drop ◽  
Knee Joints ◽  
Assist Device ◽  
Lower Extremity Weakness ◽  
Control Interface ◽  
The Individual

Lower extremity weakness is a serious problem afflicting people all over the world. Until recently, the mobility options for people with this condition have been confining and limit the individual’s functionality. Walking assist devices are presently in development to restore hands-free walking to people with lower extremity weakness. These devices provide the necessary support and power to enable the individual to restore normal ambulation. The proposed design of exoleg, a single leg external walking assist device, addresses the demographic of people with lower extremity weakness. The design includes replication of the gait cycle utilizing mechanical links and user control interface with emphasis on safety. The design couples the actuation of the knee and hip through the use of linkages connected to a single motor. The actuation of the hip is controlled by a 4 bars crank-rocker linkage system while the knee is actuated by corresponding linkages (designed in WORKING MODEL 2D, a commercial simulation software) that generates the knee kinematic profile. The angular profiles of the knee and hip actuations are compared with the actual knee and hip angular trajectories. The frame of the device incorporates a passive ankle stabilization system to compensate for the effects of foot drop. The system utilizes feedback from trigger points from pressure sensors on the foot and goniometers at the hip and knee joints to measure the angulations in gait to keep the device in synchronization with natural ambulation. An on-board microprocessor receives the feedback from the trigger points and sends the actuation signal to the motor. A conceptual design of electrostatic actuator motor is also proposed to keep the device light weight and compact.

Quick Reference: Chapter 3: The Musculoskeletal System and Chapter 4: The Nervous System

2000 ◽  
Vol 5 (3) ◽  
pp. 4-4
Keyword(s):  
Nervous System ◽  
Lower Extremity ◽  
Musculoskeletal System ◽  
Multistep Method ◽  
Manual Muscle Testing ◽  
Motor Deficits ◽  
Lower Extremity Weakness ◽  
Residual Symptoms ◽  
Muscle Testing ◽  
Almost All

Abstract Lesions of the peripheral nervous system (PNS), whether due to injury or illness, commonly result in residual symptoms and signs and, hence, permanent impairment. The AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), Fourth Edition, divides PNS deficits into sensory and motor and includes pain in the former. This article, which regards rating sensory and motor deficits of the lower extremities, is continued from the March/April 2000 issue of The Guides Newsletter. Procedures for rating extremity neural deficits are described in Chapter 3, The Musculoskeletal System, section 3.1k for the upper extremity and sections 3.2k and 3.2l for the lower limb. Sensory deficits and dysesthesia are both disorders of sensation, but the former can be interpreted to mean diminished or absent sensation (hypesthesia or anesthesia) Dysesthesia implies abnormal sensation in the absence of a stimulus or unpleasant sensation elicited by normal touch. Sections 3.2k and 3.2d indicate that almost all partial motor loss in the lower extremity can be rated using Table 39. In addition, Section 4.4b and Table 21 indicate the multistep method used for spinal and some additional nerves and be used alternatively to rate lower extremity weakness in general. Partial motor loss in the lower extremity is rated by manual muscle testing, which is described in the AMA Guides in Section 3.2d.

scholarly journals Clinical and angioarchitectural characteristics of spinal vascular malformations of the cervical spine

2020 ◽  
Vol 32 (5) ◽  
pp. 755-762 ◽  
Author(s):  
Waleed Brinjikji ◽  
Elisa Colombo ◽  
Giuseppe Lanzino
Keyword(s):  
Cervical Spine ◽  
Lower Extremity ◽  
Clinical Presentation ◽  
Vascular Malformations ◽  
Case Series ◽  
Acute Onset ◽  
Lower Extremity Weakness ◽  
Arteriovenous Fistulas ◽  
Spinal Vascular Malformations ◽  
Interventional Neuroradiologist

OBJECTIVEVascular malformations of the cervical spine are exceedingly rare. To date there have been no large case series describing the clinical presentation and angioarchitectural characteristics of cervical spine vascular malformations. The authors report their institutional case series on cervical spine vascular malformations diagnosed and treated at their institution.METHODSThe authors retrospectively reviewed all patients with spinal vascular malformations from their institution from January 2001 to December 2018. Patients with vascular malformations of the cervical spine were included. Lesions were characterized by their angioarchitectural characteristics by an interventional neuroradiologist and endovascular neurosurgeon. Data were collected on clinical presentation, imaging findings, treatment outcomes, and long-term follow-up. Descriptive statistics are reported.RESULTSOf a total of 213 patients with spinal vascular malformations, 27 (12.7%) had vascular malformations in the cervical spine. The mean patient age was 46.1 ± 21.9 years and 16 (59.3%) were male. The most common presentations were lower-extremity weakness (13 patients, 48.1%), tetraparesis (8 patients, 29.6%), and lower-extremity sensory dysfunction (7 patients, 25.9%). Nine patients (33.3%) presented with hemorrhage. Fifteen patients (55.6%) had modified Rankin Scale scores of 0–2 at the time of diagnosis. Regarding angioarchitectural characteristics, 8 patients (29.6%) had intramedullary arteriovenous malformations (AVMs), 5 (18.5%) had epidural arteriovenous fistulas (AVFs), 4 (14.8%) had paraspinal fistulas, 4 (14.8%) had mixed epidural/intradural fistulas, 3 (11.1%) had perimedullary AVMs, 2 (7.4%) had dural fistulas, and 1 patient (3.7%) had a perimedullary AVF.CONCLUSIONSThis retrospective study of 27 patients with cervical spine vascular malformations is the largest series to date on these lesions. The authors found substantial angioarchitectural heterogeneity with the most common types being intramedullary AVMs followed by epidural AVFs, paraspinal fistulas, and mixed intradural/extradural fistulas. Angioarchitecture dictated the clinical presentation as intradural shunts were more likely to present with hemorrhage and acute onset myelopathy, while dural and extradural shunts presented as either incidental lesions or gradually progressive congestive myelopathy.

scholarly journals Sleep Apnea and Unilateral Upper and Lower Extremity Allodynia as a Result of a Large Thoracic Disc Herniation: A Case Report

2021 ◽  
Author(s):  
Tyler D. Alexander ◽  
Anthony Stefanelli ◽  
Sara Thalheimer ◽  
Joshua E. Heller
Keyword(s):  
Spinal Cord ◽  
Sleep Apnea ◽  
Sexual Dysfunction ◽  
Lower Extremity ◽  
Disc Herniation ◽  
Cord Compression ◽  
Thoracic Disc Herniation ◽  
Lower Extremity Weakness ◽  
Disc Herniations ◽  
Thoracic Disc

Abstract BackgroundClinically significant disc herniations in the thoracic spine are rare accounting for approximately 1% of all disc herniations. In patients with significant spinal cord compression, presenting symptoms typically include ambulatory dysfunction, lower extremity weakness, lower extremity sensory changes, as well as bowl, bladder, or sexual dysfunction. Thoracic disc herniations can also present with thoracic radiculopathy including midback pain and radiating pain wrapping around the chest or abdomen. The association between thoracic disc herniation with cord compression and sleep apnea is not well described.Case PresentationThe following is a case of a young male patient with high grade spinal cord compression at T7-8, as a result of a large thoracic disc herniation. The patient presented with complaints of upper and lower extremity unilateral allodynia and sleep apnea. Diagnosis was only made once the patient manifested more common symptoms of thoracic stenosis including left lower extremity weakness and sexual dysfunction. Following decompression and fusion the patient’s allodynia and sleep apnea quickly resolved.ConclusionsThoracic disc herniations can present atypically with sleep apnea – a symptom which may resolve with surgical treatment.

scholarly journals Design and Experimental Evaluation of a Vertical Lift Walker for Sit-to-Stand Transition Assistance

2012 ◽  
Vol 6 (1) ◽  
Author(s):  
Thomas C. Bulea ◽  
Ronald J. Triolo
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Lower Extremity ◽  
Grip Force ◽  
Hand Function ◽  
Electrical Power ◽  
Lower Extremity Weakness ◽  
Sit To Stand ◽  
Cord Injury ◽  
Vertical Lift

A walker capable of providing vertical lift support can improve independence and increase mobility of individuals living with spinal cord injury (SCI). Using a novel lifting mechanism, a walker has been designed to provide sit-to-stand assistance to individuals with partially paralyzed lower extremity muscles. The design was verified through experiments with one individual with SCI. The results show the walker is capable of reducing the force demands on the upper and lower extremity muscles during sit-to-stand transition compared to standard walkers. The walker does not require electrical power and no grip force or harness is necessary during sit-to-stand operation, enabling its use by individuals with limited hand function. The design concept can be extended to aid other populations with lower extremity weakness.

scholarly journals Lower Extremity Motor Impairments in Ambulatory Chronic Hemiparetic Stroke: Evidence for Lower Extremity Weakness and Abnormal Muscle and Joint Torque Coupling Patterns

2017 ◽  
Vol 31 (9) ◽  
pp. 814-826 ◽  
Author(s):  
Natalia Sánchez ◽  
Ana Maria Acosta ◽  
Roberto Lopez-Rosado ◽  
Arno H. A. Stienen ◽  
Julius P. A. Dewald
Keyword(s):  
Lower Extremity ◽  
Degrees Of Freedom ◽  
Joint Torque ◽  
Motor Impairments ◽  
Lower Extremity Weakness ◽  
Joint Torques ◽  
Hemiparetic Stroke ◽  
Chronic Hemiparetic Stroke ◽  
Hip Extension ◽  
Flexion And Extension

Although global movement abnormalities in the lower extremity poststroke have been studied, the expression of specific motor impairments such as weakness and abnormal muscle and joint torque coupling patterns have received less attention. We characterized changes in strength, muscle coactivation and associated joint torque couples in the paretic and nonparetic extremity of 15 participants with chronic poststroke hemiparesis (age 59.6 ± 15.2 years) compared with 8 age-matched controls. Participants performed isometric maximum torques in hip abduction, adduction, flexion and extension, knee flexion and extension, ankle dorsi- and plantarflexion and submaximal torques in hip extension and ankle plantarflexion. Surface electromyograms (EMGs) of 10 lower extremity muscles were measured. Relative weakness (paretic extremity compared with the nonparetic extremity) was measured in poststroke participants. Differences in EMGs and joint torques associated with maximum voluntary torques were tested using linear mixed effects models. Results indicate significant poststroke torque weakness in all degrees of freedom except hip extension and adduction, adductor coactivation during extensor tasks, in addition to synergistic muscle coactivation patterns. This was more pronounced in the paretic extremity compared with the nonparetic extremity and with controls. Results also indicated significant interjoint torque couples during maximum and submaximal hip extension in both extremities of poststroke participants and in controls only during maximal hip extension. Additionally, significant interjoint torque couples were identified only in the paretic extremity during ankle plantarflexion. A better understanding of these motor impairments is expected to lead to more effective interventions for poststroke gait and posture.

Case Report: HTLV-1–Induced Adult T-Cell Leukemia and Tropical Spastic Paresis

2021 ◽  
Author(s):  
Reece Rosenthal ◽  
Julika Kaplan ◽  
Mohammed Ahmed ◽  
Martha Mims ◽  
Jill E. Weatherhead
Keyword(s):  
T Cell ◽  
Lower Extremity ◽  
Spastic Paraparesis ◽  
T Cell Leukemia ◽  
Cell Leukemia ◽  
Lower Extremity Weakness ◽  
T Lymphotropic Virus ◽  
Adult T Cell Leukemia ◽  
Spastic Paresis

Human T-lymphotropic virus type 1 (HTLV-1) is a retrovirus endemic in many areas around the world. HTLV-1 can induce the development of adult T-cell leukemia (ATL) or myelopathy/tropical spastic paraparesis (HAM/TSP). We report a patient who presented to our outpatient clinic with massive splenomegaly, weight loss, urinary retention, and lower extremity weakness for the previous 3 years. The patient was found to have positive HTLV-1 by ELISA and Western blot from peripheral blood. Evaluation of the spleen demonstrated T-cell large granular lymphocyte leukemia consistent with ATL. In addition to progressive lower extremity weakness, hyperreflexia and clonus, cerebral spinal fluid was positive for HTLV-1 by ELISA and had a reversed CD4-to-CD8 ratio consistent with HAM/TSP. These findings suggest HTLV-1 induced ATL and HAM/TSP presenting simultaneously in the same patient.

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