scholarly journals Functional Design in Rehabilitation: Modular Mechanisms for Ankle Complex

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Francesco Aggogeri ◽  
Nicola Pellegrini ◽  
Riccardo Adamini
Keyword(s):  
Plantar Flexion ◽  
Functional Design ◽  
Ankle Motion ◽  
Analysis And Design ◽  
Motion Data ◽  
Ankle Rehabilitation ◽  
Human Ankle ◽  
Current Design ◽  
Ankle Movement ◽  
Ankle Complex

This paper is aimed at presenting an innovative ankle rehabilitation device based on a parallel mechanism. A functional analysis and design are described to obtain a device able to guarantee ankle movement while patient’s body remains stationary. Human ankle is a challenging context where a series of joints are highly integrated. The proposed rehabilitation device permits a patient with walking defects to improve his or her gait. The research focuses on plantar-flexion-dorsiflexion movement. The robust design starts from an accurate modelling of ankle movements during walking, assessing motion data from healthy individuals and patients. The kinematics analysis and functional evaluations lead the study and development of the articulated system. In particular, results of simulations support the effectiveness of the current design. A 3D prototype is presented highlighting that the ankle motion is successfully demonstrated.

Ankle Motion after External Fixation of Tibial Fractures

1988 ◽  
Vol 81 (1) ◽  
pp. 19-21 ◽  
Author(s):  
G J Taylor ◽  
R L Allum
Keyword(s):  
External Fixation ◽  
Plantar Flexion ◽  
Tibial Fractures ◽  
Ankle Motion ◽  
Ankle Movement ◽  
The Mean ◽  
The Difference ◽  
Tissue Trauma ◽  
Ankle Function

Loss of ankle movement is a complication of severe tibial fractures. This can be exacerbated if the foot is allowed to drop into equinus, particularly when an external fixator is employed. The range of ankle motion following external fixation of tibial fractures as compared to the opposite normal ankle was studied in 40 of 55 patients treated over a ten-year period. Nine were excluded due to other causes of ankle stiffness, leaving 31 cases for analysis. The mean follow up was 2 years 7 months (range 1 year to 8 years 3 months), and union had occurred by a mean of 35 weeks (range 9–100 weeks). The mean loss of ankle movement was 8° of plantar-flexion and 12° of dorsiflexion (overall loss 20°), the difference between the two being highly significant (P> 0.001, t test). Loss of ankle motion closely paralleled the degree of soft tissue trauma, being 6° for closed fractures and 22° for open fractures (0.05 > P> 0.02). Ankle function is therefore at risk when a severe tibial fracture is treated by external fixation, and appropriate measures should be taken to preserve movement and prevent an equinus contracture.

Design and Analysis of a Mechanism of Ankle Rehabilitation Robot

2013 ◽  
Vol 655-657 ◽  
pp. 1038-1042
Author(s):  
Shi De Zhang ◽  
Qiang Wang ◽  
Ping Zhou
Keyword(s):  
Parallel Mechanism ◽  
Screw Theory ◽  
Rehabilitation Robot ◽  
Damage Analysis ◽  
Mechanism Analysis ◽  
Ankle Motion ◽  
Ankle Rehabilitation ◽  
Human Ankle ◽  
New Type ◽  
Singular Configuration

This paper puts forward a new type of wearable parallel mechanism on the basis of the analysis of the human ankle motion mechanism, damage analysis and methods of rehabilitation. The mechanism can realize three DOFs rotation of ankle. And the axes of the three rotations intersect at a point. Did the position and velocity analysis using the screw theory of mechanism analysis. The singularity and dexterity of this mechanism are also analyzed. According to the simulation result, this parallel mechanism has no singular configuration or uncertainty configuration in human lower limb workspace, has good maneuverability.

scholarly journals Reliability of Bi-Axial Ankle Stiffness Measurement in Older Adults

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1162
Author(s):  
Hogene Kim ◽  
Sangwoo Cho ◽  
Hwiyoung Lee
Keyword(s):  
Older Adults ◽  
Range Of Motion ◽  
Angular Displacement ◽  
Plantar Flexion ◽  
Significant Negative Correlation ◽  
Talocrural Joint ◽  
Ankle Foot Orthosis ◽  
Ankle Stiffness ◽  
Ankle Movement ◽  
Test Retest Reliability

This study involves measurements of bi-axial ankle stiffness in older adults, where the ankle joint is passively moved along the talocrural and subtalar joints using a custom ankle movement trainer. A total of 15 elderly individuals participated in test–retest reliability measurements of bi-axial ankle stiffness at exactly one-week intervals for validation of the angular displacement in the device. The ankle’s range of motion was also compared, along with its stiffness. The kinematic measurements significantly corresponded to results from a marker-based motion capture system (dorsi-/plantar flexion: r = 0.996; inversion/eversion: r = 0.985). Bi-axial ankle stiffness measurements showed significant intra-class correlations (ICCs) between the two visits for all ankle movements at slower (2.14°/s, ICC = 0.712) and faster (9.77°/s, ICC = 0.879) speeds. Stiffness measurements along the talocrural joint were thus shown to have significant negative correlation with active ankle range of motion (r = −0.631, p = 0.012). The ankle movement trainer, based on anatomical characteristics, was thus used to demonstrate valid and reliable bi-axial ankle stiffness measurements for movements along the talocrural and subtalar joint axes. Reliable measurements of ankle stiffness may help clinicians and researchers when designing and fabricating ankle-foot orthosis for people with upper-motor neuron disorders, such as stroke.

scholarly journals Closing the Wearable Gap: Mobile Systems for Kinematic Signal Monitoring of the Foot and Ankle

2018 ◽  
Author(s):  
Tony Luczak ◽  
David Saucier ◽  
Reuben F. Burch ◽  
John E. Ball ◽  
Harish Chander ◽  
...  
Keyword(s):  
Liquid Metal ◽  
Plantar Flexion ◽  
Wheatstone Bridge ◽  
Complex Model ◽  
Mobile Systems ◽  
Measurement Unit ◽  
Strength And Conditioning ◽  
Computing Unit ◽  
Metal Sensors ◽  
Ankle Complex

Interviews from strength and conditioning coaches across all levels of athletic competition identified their two biggest concerns with the current state of wearable technology: (a) the lack of solutions that accurately capture data "from the ground up" and (b) the lack of trust due to inconsistent measurements. The purpose of this research is to investigate the use of liquid metal sensors, specifically Liquid Wire sensors, as a potential solution for accurately capturing ankle complex movements such as plantar flexion, dorsiflexion, inversion, and eversion. Sensor stretch linearity was validated using a Micro-Ohm Meter and a Wheatstone bridge circuit. Sensors made from different substrates were also tested and discovered to be linear at multiple temperatures. An ankle complex model and computing unit for measuring resistance values were developed to determine sensor output based on simulated plantar flexion movement. The sensors were found to have a significant relationship between the positional change and the resistance values for plantar flexion movement. The results of the study ultimately confirm the researchers' hypothesis that liquid metal sensors, and Liquid Wire sensors specifically, can serve as a mitigating substitute for inertial measurement unit (IMU) based solutions that attempt to capture specific joint angles and movements.

scholarly journals Clinical and Radiographic Outcomes of 3D Printed Total Talus Arthroplasty

2019 ◽  
Vol 4 (4) ◽  
pp. 2473011419S0037
Author(s):  
Daniel Scott ◽  
John Steele ◽  
Amanda Fletcher ◽  
Selene Parekh
Keyword(s):  
Avascular Necrosis ◽  
Weight Bearing ◽  
Treatment Options ◽  
Ankle Motion ◽  
Motion Data ◽  
Radiographic Outcomes ◽  
Significant Difference ◽  
3D Printed ◽  
Vas Scores

Category: Ankle, Ankle Arthritis, Hindfoot, Trauma Introduction/Purpose: Patients with talar avascular necrosis have limited treatment options to manage their symptoms. Historically, surgical options have been limited and can leave patients with little ankle motion and have high failure rates. The use of custom 3D printed total talar replacements (TTR) has arisen as a treatment option for these patients, possibly allowing for better preservation of hind-foot motion. Patients undergoing TTR will demonstrate a statistically significant improvement in FAOS scores at one year after surgery. Methods: We retrospectively reviewed 15 patients who underwent a TTR over 2 years. Patient outcomes were reviewed including age, sex, comorbidities, etiology of talar pathology, number and type of prior surgeries, pre-operative and post-operative weight bearing radiographs, as well as FAOS and VAS scores, and range of motion. Data analysis performed with student T-test and multivariate regression. Results: Results: FAOS scores showed statistically significant improvements post-operatively as compared to pre-operative scores. There was a statistically significant decrease in VAS pain scores from 7.0 pre-operatively to 3.4 post operatively. There was no significant difference in pre-operative and post-operative coronal and sagittal alignment on weight bearing radiographs. All FAOS sub-score shows statistically significant improvements, with the exception of the sports/recreation sub-scale, did show a trend towards improved outcomes (p =0.19). Average follow-up was 12.8 months. Conclusion: Our hypothesis was confirmed that these patients show statistically significant improvements in AOFS and VAS scores at 1 year. Sagittal and coronal alignment was well maintained at an average of 1 year following surgery. TTR represents an exciting treatment options for patients with talar avascular necrosis, though longer-term follow-up is needed.

Functional Electrical Stimulation for Equilibrium-Point Control of Human Ankle Movement: Frequency Domain System Identification of Human Ankle Dynamics

2014 ◽  
Author(s):  
Yuto Yamashita ◽  
Kazuya Maegaki ◽  
Kazuhiro Matsui ◽  
Takanori Oku ◽  
Kanna Uno ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Equilibrium Point ◽  
Ankle Joint ◽  
Movement Analysis ◽  
Human Movement ◽  
Order System ◽  
Force Output ◽  
Mechanical Stiffness ◽  
Human Ankle ◽  
Ankle Movement

This paper presents a novel method for creating an electrical stimulation pattern to control the equilibrium-point (EP) of human ankle movement. Focusing on the synergetic activation of agonist–antagonist (AA) muscles, the proposed method employs the ES-AA ratio (the ratio of the electrical stimulation levels for AA muscles) and the ES-AA sum (the sum of the electrical stimulation levels for AA muscles), which are based on the AA ratio (the ratio of the electromyography (EMG) voltage levels for AA muscles) and the AA sum (the sum of the EMG voltage levels for AA muscles) used in human movement analysis [1, 2]. The ES-AA ratio is related to the EP of the joint whereas the ES-AA sum is associated with mechanical stiffness of the joint. Using the AA concepts, we estimated the transfer function between the input ES-AA ratio (for the tibialis anterior (TA ) and gastrocnemius (GC)) and the force output of the endpoint in the ankle joint in an isometric environment by investigating the frequency characteristics, and finally found that the ankle-joint system was a second-order system with dead time in terms of the ES-AA ratio and foot force.

scholarly journals Musculoskeletal modelling of human ankle complex: Estimation of ankle joint moments

2017 ◽  
Vol 44 ◽  
pp. 75-82 ◽  
Author(s):  
Prashant K. Jamwal ◽  
Shahid Hussain ◽  
Yun Ho Tsoi ◽  
Mergen H. Ghayesh ◽  
Sheng Quan Xie
Keyword(s):  
Ankle Joint ◽  
Joint Moments ◽  
Musculoskeletal Modelling ◽  
Human Ankle ◽  
Ankle Complex

Early Outcomes of 3D Printed Total Talus Arthroplasty

2019 ◽  
Vol 13 (5) ◽  
pp. 372-377 ◽  
Author(s):  
Daniel J. Scott ◽  
John Steele ◽  
Amanda Fletcher ◽  
Selene G. Parekh
Keyword(s):  
Treatment Option ◽  
Treatment Options ◽  
Case Series ◽  
Level Of Evidence ◽  
Ankle Motion ◽  
Motion Data ◽  
Number Of Patients ◽  
3D Printed ◽  
Radiographic Alignment

Background. Patients with talar avascular necrosis (AVN) have limited treatment options to manage their symptoms. Historically, surgical options have been limited and can leave patients with little ankle motion and have high failure rates. The use of custom 3D printed total talar replacements (TTRs) has arisen as a treatment option for these patients, possibly allowing better preservation of hindfoot motion. We hypothesized that patients undergoing TTR will demonstrate a statistically significant improvement in Foot and Ankle Outcome Score (FAOS) at 1 year after surgery. Methods. We retrospectively reviewed 15 patients who underwent a TTR over a 2-year period. Patient outcomes were reviewed, including age, sex, comorbidities, etiology of talar pathology, number and type of prior surgeries, radiographic alignment, FAOS and Visual Analog Scale (VAS) score, and range of motion. Data analysis was performed with Student t-tests and multivariate regression. Results. FAOSs and VAS scores showed statistically significant improvements postoperatively as compared with preoperative scores. There was a statistically significant decrease in VAS pain scores from 7.0 preoperatively to 3.6 (P < .001). Average follow-up was 12.8 months. With the number of patients available, there was no statistically significant change in radiographic alignment parameters postoperatively as compared with preoperatively (P values ranged from .225 to .617). Conclusion. Our hypothesis that these patients show statistically significant improvements in FAOSs at 1 year was confirmed. TTR represents an exciting treatment option for patients with talar AVN, though longer-term follow-up is needed. Level of Evidence: Level IV: Case series

Main Issues on the Seismic Design of Industrial Piping Systems and Components

2013 ◽  
Author(s):  
Fabrizio Paolacci ◽  
Md. Shahin Reza ◽  
Oreste S. Bursi ◽  
Arnold M. Gresnigt ◽  
Anil Kumar
Keyword(s):  
Seismic Design ◽  
Seismic Analysis ◽  
Experimental Investigations ◽  
Piping System ◽  
Analysis And Design ◽  
Correct Definition ◽  
Component Design ◽  
Piping Systems ◽  
Current Design ◽  
Bolted Flange

A significant number of damages in piping systems and components during recent seismic events have been reported in literature which calls for a proper seismic design of these structures. Nevertheless, there exists an inadequacy of proper seismic analysis and design rules for a piping system and its components. Current seismic design Codes are found to be over conservative and some components, e.g., bolted flange joints, do not have guidelines for their seismic design. Along this line, this paper discusses about the main issues on the seismic analysis and design of industrial piping systems and components. Initially, seismic analysis and component design of refinery piping systems are described. A review of current design approaches suggested by European (EN13480:3) and American (ASME B31.3) Codes is performed through a Case Study on a piping system. Some limits of available Codes are identified and a number of critical aspects of the problem e.g., dynamic interaction between pipes and rack, correct definition of the response factor and strain versus stress approach, are illustrated. Finally, seismic performance of bolted flange joints based on the results of experimental investigations carried out by the University of Trento, Italy, will be discussed.

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