scholarly journals Effects of bicycle geometry and riding position on the potential of residual limb muscles to pedaling with a transfemoral prosthesis: a computer simulation study

2019 ◽  
Author(s):  
Yusuke Okita ◽  
Takashi Nakamura
Keyword(s):  
Pelvic Tilt ◽  
Knee Kinematics ◽  
Fine Tuning ◽  
Seat Height ◽  
Hip Kinematics ◽  
Acceleration Analysis ◽  
Seating Position ◽  
Transfemoral Prosthesis ◽  
Crank Length ◽  
Muscle Potential

AbstractWe performed musculoskeletal simulations to provide information on the effects of riding position and bicycle geometry on pedaling with a transfemoral prosthesis. Sixty-four models and their corresponding kinematics in one pedaling cycle were generated from the baseline one-leg cycling model by varying one of the six variables (seat height, seat-tube angle, crank length, pelvic tilt, anteroposterior seating position, and thigh length relative to the leg). Induced acceleration analysis was performed to compute the potentials of the residual hip muscles for crank rotation in each model. The simulation results quantified the effects of each variable on the hip and knee kinematics and muscle potential during a pedaling cycle; seat height, crank length, and pelvic tilt were the primary candidates for bicycle fitting considering their accessibility and simple effects on the joint kinematics and muscle potential. The seat-tube angle (similar to pelvic tilt) and the anteroposterior seating position (similar to seat height and seat-tube angle) seemed to have an effect similar to the other variables and thus can be reserved for fine-tuning after gross fitting of the bicycle. Although not considered for adjustment, considering the effects of the thigh length could help as it affects hip kinematics and muscle potentials.

An Architecture for Direct Measurement of Transfemoral Prosthesis Gait Beyond the Gait Laboratory Setting

2014 ◽  
Author(s):  
Jonathan A. Gacioch ◽  
Kevin B. Fite ◽  
Adam K. Arabian ◽  
Toshiki Kobayashi ◽  
David A. Boone ◽  
...  
Keyword(s):  
Knee Kinematics ◽  
Knee Joints ◽  
Single Subject ◽  
Laboratory Setting ◽  
Transfemoral Amputation ◽  
Kinetic Measurements ◽  
Prosthetic Knee ◽  
Rapid Acquisition ◽  
Composite Energy ◽  
Transfemoral Prosthesis

The work presented here details the development of a wireless instrumentation architecture for direct gait measurement in a transfemoral prosthesis. The system comprises a pair of multi-axis load cells located proximal to the ankle and knee joints of the prosthesis that provide a measure of moments and axial force above and below the prosthetic knee. The kinetic measurements are supplemented with knee kinematics measured using a modular goniometer attached lateral to the prosthetic knee and ground contact as indicated with a pneumatic sensor at the prosthetic heel. Each instrument wirelessly transmits collected data to host PCs, enabling direct gait measurements free of the constraints of a conventional gait laboratory setting. The data acquisition system was evaluated with a single subject with unilateral transfemoral amputation walking with a polycentric knee, composite energy-return foot, and daily-use socket. Experimental results were collected for the subject walking through a theater, enabling the rapid acquisition of gait data for level-ground walking and incline ascent/descent without the need for a motion-capture camera array or floor-embedded force plates.

scholarly journals Spine, Pelvis and Hip Kinematics—Characterizing the Axial Plane in Healthy and Osteoarthritic Hips

2021 ◽  
Vol 11 (21) ◽  
pp. 9921
Author(s):  
Danilo S. Catelli ◽  
Brendan Cotter ◽  
Mario Lamontagne ◽  
George Grammatopoulos
Keyword(s):  
Pelvic Tilt ◽  
Hip Osteoarthritis ◽  
Axial Plane ◽  
Sacral Slope ◽  
Healthy Individuals ◽  
Spinopelvic Parameters ◽  
Dynamic Motion ◽  
Hip Disease ◽  
Hip Kinematics ◽  
Hip Flexion

Abnormal spinopelvic movements are associated with inferior outcomes following total hip arthroplasty (THA). This study aims to (1) characterize the agreement between dynamic motion and radiographic sagittal assessments of the spine, pelvis, and hip; (2) determine the effect of hip osteoarthritis (OA) on kinematics by comparing healthy individuals with pre-THA patients suffering from uni- or bilateral hip OA. Twenty-four OA patients pre-THA and eight healthy controls underwent lateral spinopelvic radiographs in standing and seated bend-and-reach (SBR) positions. Lumbar-lordosis (LL), sacral-slope (SS), and pelvic–femoral (PFA) angles were measured in both positions, and the differences (Δ) between SBR and standing were computed to assess spine flexion (SF), pelvic tilt (PT), and hip flexion (HF), respectively. Dynamic SBR and seated maximal trunk rotation (STR) tasks were performed at the biomechanics laboratory. Peak sagittal and axial kinematics for spine, pelvis, and hip, and range of motion (ROM), were calculated for SBR and STR. Radiograph readings correlated with sagittal kinematics during SBR for ΔLL and SFmax (r = 0.66, p < 0.001), ΔPT and PTmax (r = 0.44, p = 0.014), and ΔPFA and HFmax (r = 0.70, p < 0.001), with a satisfactory agreement in Bland–Altman analyses. Sagittal SBR spinal (r = 0.33, p = 0.022) and pelvic (r =0.35, p = 0.018) flexions correlated with the axial STR rotations. All axial spinopelvic parameters were different between the OA patients and controls, with the latter exhibiting significantly greater mobility and less variability. Bilaterally affected patients exhibited lower peak and ROM compared to controls. The biomechanics laboratory performed reliable assessments of spinopelvic and hip characteristics, in which the axial plane can be included. The sagittal and axial pelvic kinematics correlate, illustrating that pelvic rotation abnormalities are likely also contributing to the inferior outcomes seen in patients with abnormal spinopelvic flexion characteristics. Axial rotations of the pelvis and spine were least in patients with bilateral hip disease, further emphasizing the importance of the hip–pelvic–spine interaction.

The Effects of Curved Foot Design Parameters on Planar Biped Walking

2012 ◽  
Author(s):  
Anne E. Martin ◽  
James P. Schmiedeler
Keyword(s):  
Knee Kinematics ◽  
Substantial Effect ◽  
Energetic Cost ◽  
Design Parameters ◽  
Energetic Efficiency ◽  
Bipedal Robots ◽  
Healthy Human ◽  
Circular Arc ◽  
Gait Kinematics ◽  
Hip Kinematics

Although the nature of their gaits is similar, planar bipeds with curved feet have been shown experimentally to be more energetically efficient than those with point feet. Further, both healthy human feet and prosthetic feet can be modeled as a circular arc with the center of curvature in front of the shank. Thus, understanding the effects of a curved foot’s properties on the energetic cost of gait and on gait kinematics has the potential to improve both bipedal robots and prosthesis design. To date, there has not been a systematic study of the effects of changing the foot radius and center of curvature location on symmetric bipeds. This paper explores the effects of changing the curved foot’s geometric properties for both two- and five-link planar, underactuated bipeds with instantaneous transfer of support at impact. It is found that the foot radius has a substantial effect on the energetic efficiency of a gait regardless of the morphology of the biped. The effect of foot center of curvature location on energy efficiency is dependent on the morphology of the biped and is much less significant than the effect of foot radius. Both the foot radius and center of curvature location affect the knee kinematics of the five-link biped. The foot radius affects the hip kinematics of the two-link biped.

scholarly journals In-vivo precision of a non-invasive ultrasound-based device to measure pelvic tilt for THA

10.29007/ql68 ◽  
2019 ◽  
Author(s):  
Guillaume Dardenne ◽  
Jean-Philippe Pluchon ◽  
Hoel Letissier ◽  
Aziliz Guezou-Philippe ◽  
Romain Gérard ◽  
...  
Keyword(s):  
Pelvic Tilt ◽  
Intraclass Correlation ◽  
High Body Mass Index ◽  
Standing Position ◽  
Patient Specific ◽  
Non Invasive ◽  
User Expertise ◽  
Hip Kinematics ◽  
Expertise Level

The cup orientation plays a major role in the long-term implant stability following Total Hip Arthroplasty (THA). Because of the patient specific spine-hip kinematics, the safe zone introduced by Lewinnek is more and more controversial. Several solutions have been recently developed to take into account such parameter for THA but are all either invasive, difficult to use or expensive. A non-invasive ultrasound (US) based device has been recently proposed which allows the acquisition of the pelvic tilt in different daily positions. The goal of this study is to analyze the in-vivo intra and inter-observer precision of this device. Measurements were realized by three physicians on three healthy subjects having a low, medium and high Body Mass Index (BMI). Among the three physicians, there were an expert, an intermediate, and a novice user. For each subject, the pelvic tilt was measured ten times by the three physicians in the supine, standing and sitting positions. The inter and intra-observer precisions have been analyzed using the intraclass correlation coefficient (ICC) and according to the BMI, the positions and the user expertise level. The inter-observer precision was therefore excellent whatever the BMI. It was also excellent regarding the supine and the sitting positions and good concerning the standing position. The in-vivo intra-observer precision was excellent for all measurements and whatever the user’s expertise, the BMI and the positions. This study shows therefore that the precision of our system meets the clinical requirement. Introduction

Preliminary Analysis of StrongArm® Ergoskeleton on Knee and Hip Kinematics and User Comfort

2017 ◽  
Vol 61 (1) ◽  
pp. 1346-1350 ◽  
Author(s):  
Hunter DeBusk ◽  
Kari Babski-Reeves ◽  
Harish Chander
Keyword(s):  
Body Weight ◽  
Preliminary Analysis ◽  
Perceived Exertion ◽  
Knee Kinematics ◽  
Hand Dominance ◽  
The Poor ◽  
Hip Kinematics ◽  
Box Lifting ◽  
Lifting Task ◽  
User Comfort

This study was constructed to assess the influence of wearing semi-soft exoskeletons on hip and knee kinematics when engaging in a box lifting task. Six healthy college aged students (age: 21.7 ± 2.3; gender: 4 males, 2 females; height: 177.0 ± 3.4 cm; weight: 77.1 ± 17.9 kg; hand dominance: all right) completed box lifting tasks (at 10% and 20% of their body weight) while wearing no exoskeleton and two exoskeleton designs. Lifting a box at 20% body weight increased perceived exertion and was associated with poor hip and knee kinematics in some conditions. Wearing the StrongArm® V22 ERGOSKELETON without hand cables may diminish some of the poor kinematics associated with lifting objects.

scholarly journals Do orthotic walkers affect knee and hip function during gait?

2014 ◽  
Vol 40 (1) ◽  
pp. 137-141 ◽  
Author(s):  
Jim Richards ◽  
Katherine Payne ◽  
Darren Myatt ◽  
Ambreen Chohan
Keyword(s):  
Knee Kinematics ◽  
Gait Pattern ◽  
Foot And Ankle ◽  
Joint Mechanics ◽  
Hip Joints ◽  
Normal Gait ◽  
Hip Function ◽  
Hip Kinematics ◽  
Analysis System ◽  
Healthy Participants

Background and Aim:Much previous research on orthotic walkers has focussed on their ability to offload structures in the foot and ankle; however, little is known about their effects on lower limb mechanics. This study aimed to determine effects of two orthotic walkers on the biomechanics of the knee and hip joints compared to standardised footwear.Technique:A total of 10 healthy participants walked under three conditions: Walker A (Össur, Iceland), Walker B (DJO Global, USA) and standardised footwear (Hotter, UK). Kinematic and kinetic data were collected using a Qualisys motion analysis system (Qualisys Medical AB, Sweden) and force plates (AMTI, Boston, MA, USA). Significant differences were seen in hip kinematics and knee moments between walkers and standardised footwear and in knee kinematics between Walker A and standardised footwear.Discussion:Both walkers show significant kinematic and kinetic differences compared with standardised footwear; however, Walker A appeared to produce greater deviation, including potentially damaging greater hyperextension moments at the knee.Clinical relevanceFurther research is needed into the effects of orthotic walkers on knee and hip joint mechanics, which should help to inform future designs of walker, with greater focus on obtaining a more normal gait pattern.

Fine-Tuning Futures

ASHA Leader ◽  
2017 ◽  
Vol 22 (6) ◽  
Author(s):  
Christi Miller
Keyword(s):  
Fine Tuning

Food Safety Security: A new Concept for Enhancing Food Safety Measures

2012 ◽  
Vol 82 (3) ◽  
pp. 216-222 ◽  
Author(s):  
Venkatesh Iyengar ◽  
Ibrahim Elmadfa
Keyword(s):  
Food Safety ◽  
Hazard Analysis ◽  
Warning System ◽  
Shared Responsibility ◽  
Fine Tuning ◽  
Strategic Action ◽  
Surveillance Network ◽  
Measurement Systems ◽  
Critical Control Points ◽  
The Impact

The food safety security (FSS) concept is perceived as an early warning system for minimizing food safety (FS) breaches, and it functions in conjunction with existing FS measures. Essentially, the function of FS and FSS measures can be visualized in two parts: (i) the FS preventive measures as actions taken at the stem level, and (ii) the FSS interventions as actions taken at the root level, to enhance the impact of the implemented safety steps. In practice, along with FS, FSS also draws its support from (i) legislative directives and regulatory measures for enforcing verifiable, timely, and effective compliance; (ii) measurement systems in place for sustained quality assurance; and (iii) shared responsibility to ensure cohesion among all the stakeholders namely, policy makers, regulators, food producers, processors and distributors, and consumers. However, the functional framework of FSS differs from that of FS by way of: (i) retooling the vulnerable segments of the preventive features of existing FS measures; (ii) fine-tuning response systems to efficiently preempt the FS breaches; (iii) building a long-term nutrient and toxicant surveillance network based on validated measurement systems functioning in real time; (iv) focusing on crisp, clear, and correct communication that resonates among all the stakeholders; and (v) developing inter-disciplinary human resources to meet ever-increasing FS challenges. Important determinants of FSS include: (i) strengthening international dialogue for refining regulatory reforms and addressing emerging risks; (ii) developing innovative and strategic action points for intervention {in addition to Hazard Analysis and Critical Control Points (HACCP) procedures]; and (iii) introducing additional science-based tools such as metrology-based measurement systems.

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