Analysis of locomotor adaptations in young children with limb loss in an early prosthetic knee prescription protocol

2013 ◽  
Vol 38 (1) ◽  
pp. 54-61 ◽  
Author(s):  
Mark Geil ◽  
Colleen Coulter
Keyword(s):  
Young Children ◽  
Knee Flexion ◽  
Knee Prosthesis ◽  
Swing Phase ◽  
Clinical Protocols ◽  
Full Extension ◽  
Walking Gait ◽  
Prosthetic Knee ◽  
Before And After ◽  
Locomotor Adaptations

Background: Traditionally, clinical protocols for the treatment of young children who require a knee prosthesis have favored stability, with the prosthetic knee locked into full extension until after the child has learned to walk. Recently, an Early Knee protocol has been investigated, in which children receive an articulating knee in their first prosthesis and use it while learning to crawl and walk. Objectives: This study investigated the presence of swing phase clearance adaptations in the walking gait of seven young children aged 18–92 months, who had been fitted according to the Early Knee protocol. Study design: Before-and-after experimental design. Methods: Each subject completed walking trials with the knee freely flexing and trials with the knee locked into full extension to mimic a traditional knee protocol. Results: Subjects utilized the articulating knee in walking, with an average of 70.4° of peak swing phase knee flexion. Some clearance adaptations were present with the flexing knee; more were present and their magnitude was increased when the knee was locked. In particular, there was a statistically significant increase in circumduction. Conclusions: These results suggest that the Early Knee protocol can reduce the adoption of clearance adaptations while walking is developing. Clinical relevance Treatment of young children who require a knee prosthesis is inconsistent. Traditionally, no knee is provided until independent walking is achieved. A newer Early Knee protocol provides an articulating knee in the first prosthesis. This study found that children use the articulating knee in walking and develop fewer clearance adaptations.

scholarly journals Genetic Algorithms Based Approach for Designing Spring Brake Orthosis – Part I: Spring Parameters

2012 ◽  
Vol 9 (3) ◽  
pp. 303-316 ◽  
Author(s):  
M. S. Huq ◽  
M. O. Tokhi
Keyword(s):  
First Principles ◽  
Knee Flexion ◽  
Gait Cycle ◽  
Sagittal Plane ◽  
Swing Phase ◽  
Full Extension ◽  
Torsion Spring ◽  
Constant Torque ◽  
Spring Type ◽  
Hip Flexion

Spring brake orthosis (SBO) concentrates purely on the knee to generate the swing phase of the paraplegic gait with the required hip flexion occurring passively as a consequence of the ipsilateral knee flexion, generated by releasing the torsion spring mounted at the knee joint. Electrical stimulation then drives the knee back to full extension, as well as restores the spring potential energy. In this paper, genetic algorithm (GA) and its variant multi-objective GA (MOGA) is used to perform the search operation for the ‘best’ spring parameters for the SBO spring mounted on an average sized subject simulated in the sagittal plane. Conventional torsion spring is tested against constant torque type spring in terms of swing duration as, based on first principles, it is hypothesized that constant torque spring would be able to produce slower SBO swing phase as might be preferred in assisted paraplegic gait. In line with the hypothesis, it is found that it is not possible to delay the occurrence of the flexion peak of the SBO swing phase further than its occurrence in the natural gait. The use of conventional torsion spring causes the swing knee flexion peak to appear rather faster than that of the natural gait, resulting in a potentially faster swing phase and hence gait cycle. The constant torque type spring on the other hand is able to stretch duration of the swing phase to some extent, rendering it the preferable spring type in SBO.

Design of a Sports Knee Prosthesis

1999 ◽  
Author(s):  
Denis J. DiAngelo ◽  
Charles E. Evans
Keyword(s):  
Energy Expenditure ◽  
Knee Flexion ◽  
Knee Prosthesis ◽  
Weight Bearing ◽  
Impact Loads ◽  
Computation Model ◽  
Prosthetic Knee ◽  
Locking Mechanism ◽  
Gait Study ◽  
Intact Limb

Abstract Typical walking prostheses maintain stability during stance with a knee locking mechanism; i.e., a frictional device (mechanical brake) or free rotating knee joint (single pinned or multi-link system) held in a hyper-extended orientation (de Vries, 1995). Attempts to jog with a walking prosthesis are difficult and unsafe. A previous gait study of a “pogo-stick” A/K jogging prosthesis found that the device provided alternating periods of support and non-support between the amputated and non-amputated sides, but required greater energy expenditure from the intact limb and induced larger impact loads (DiAngelo et al., 1989). A computer modeling technique was used to design a multi-link above-knee (A/K) prosthesis that provided continuous, controlled knee flexion during weight bearing and free knee rotation during swing. Aspects of the design were improved energy expenditure, symmetrical gait, and reduced impact loading. Biomechanical data for the computation model was obtained from a gait study of an A/K amputee jogger. The objective of the study was to develop prosthetic knee that provided continuous knee flexion throughout weight bearing and free rotation during swing.

The Effect of Lateral Opening Wedge Distal Femoral Varus Osteotomy on Tibiofemoral Contact Mechanics Through Knee Flexion

2018 ◽  
Vol 46 (13) ◽  
pp. 3237-3244 ◽  
Author(s):  
James D. Wylie ◽  
Bastian Scheiderer ◽  
Elifho Obopilwe ◽  
Joshua B. Baldino ◽  
Colin Pavano ◽  
...  
Keyword(s):  
Contact Pressure ◽  
Contact Area ◽  
Knee Flexion ◽  
Plate Fixation ◽  
Lateral Compartment ◽  
Opening Wedge ◽  
Full Extension ◽  
Varus Osteotomy ◽  
Before And After ◽  
Lateral Opening Wedge

Background: Lateral opening wedge distal femoral osteotomy (DFO) unloads a diseased lateral compartment of the knee in patients with genu valgum. To the best of our knowledge, there are no biomechanical studies investigating the effect of knee flexion on contact pressure and area after DFO. Hypothesis: As knee flexion angles increase, DFO will be less effective at unloading the lateral compartment of the knee. Study Design: Controlled laboratory study. Methods: Lateral opening wedge DFO was performed, correcting a mean of 7°, in 10 cadaveric knees using plate fixation. Tibiofemoral contact pressure was measured in 0°, 15°, 30°, 45°, 60°, and 75° of knee flexion before and after osteotomy using electronic sensors. Peak contact pressure (PCP), mean contact pressure (MCP), and contact area were measured for each condition. Anatomic dissection quantified the tibiofemoral contact position on the distal femur in all degrees of flexion. Mixed-effects regression analyses were used to compare the change in variables before and after osteotomy and between flexion angles. Results: One sample had to be excluded because of tibiofemoral arthritis. MCP decreased in the lateral compartment after DFO throughout all degrees of flexion (all P < .05) but to the greatest extent in 0° of flexion. When examining the percentage of MCP in the lateral compartment, this decreased after DFO at 0° (70.4% to 40.0%; P < .001), 15° (65.1% to 52.1%; P < .001), 30° (60.7% to 52.0%; P = .003), 45° (55.8% to 49.7%; P = .033), and 60° (51.9% to 44.2%; P = .010) but not at 75° (50.2% to 45.3%; P = .112). PCP decreased in the lateral compartment after DFO at 0° (2.41 to 1.34 MPa; P < .001), 15° (2.50 to 1.81 MPa; P < .001), 30° (2.28 to 1.93 MPa; P = .039), 45° (2.21 to 1.73 MPa; P = .005), 60° (2.15 to 1.71 MPa; P = .009), and 75° (1.95 to 1.49 MPa; P = .012). The percentage of contact area decreased in the lateral compartment in full extension (68.7% to 48.1%; P = .007) but not at any other degree of flexion (all P > .05). Conclusion: DFO decreased lateral compartment pressure. However, it had the greatest effect in full knee extension. Clinical Relevance: DFO decreased contact pressure in the lateral compartment but more effectively decreased contact pressure in the more anterior aspects of the femoral articular cartilage.

scholarly journals Analysis of the swing phase dynamics and muscular effort of the above-knee amputee for varying prosthetic shank loads

1990 ◽  
Vol 14 (3) ◽  
pp. 125-135 ◽  
Author(s):  
S. A. Hale
Keyword(s):  
Knee Flexion ◽  
Walking Speed ◽  
Angular Acceleration ◽  
Swing Phase ◽  
Phase Dynamics ◽  
Prosthetic Knee ◽  
The Moment ◽  
Gravitational Moment ◽  
Load Conditions ◽  
Muscular Effort

The purpose of this study was to determine the effect of varying prosthetic shank mass, while maintaining the mass centre location and moment of inertia, on the swing phase kinematics, kinetics and hip muscular effort of free speed above-knee (AK) amputee gait. Six AK amputees, wearing similar prosthetic designs, had three load conditions applied to their prosthetic shank: 1) Load 0-unloaded (X − 39.1% sound shank mass), 2) Load 1–75%, and 3) Load 2–100% sound leg mass. Despite increases in shank mass from 1.33 to 3.37 kg the AK amputee was able to maintain a consistent swing time and walking speed. As load increased, there were significant changes in the maximum knee and hip displacements, as well as phasic shifting. The prosthetic knee Resultant Joint Moment (RJM) was negligible while the shank was accelerating (periods 1 and 2), but was a major contributor during shank deceleration (periods 3 and 4). During periods 1 and 2 the principle contributors to the shank acceleration (forces resisting excessive knee flexion) were the gravitational moment (S-G) and the moment due to thigh angular acceleration (S-AT). During the periods of shank acceleration (sections 1 and 2), there was not a significant increase in the hip muscular effort. However, during sections 3 and4, the periods associated with shank deceleration, there were siginficant increases in the hip muscular effort. The hip muscular effort for the complete swing phase increased as load increased by 36.7% and 71.3% for loads 1 and 2. Despite the significant increases in hip muscular effort, four of the six subjects preferred load 1 condition.

scholarly journals Unilateral lateral rectus recession is an effective surgery for intermittent exotropia in young children

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Oriel Spierer ◽  
Abraham Spierer
Keyword(s):  
Young Children ◽  
Success Rate ◽  
Lateral Rectus ◽  
Intermittent Exotropia ◽  
Age At Surgery ◽  
Surgical Methods ◽  
Before And After ◽  
The Mean ◽  
Consecutive Esotropia

Abstract Background Different surgical methods have been suggested for the correction of intermittent exotropia. Unilateral lateral rectus recession has been described as a surgical alternative for small and moderate-angle exotropia. In general, previous studies did not focus on the outcomes of unilateral lateral rectus recession in young children with intermittent exotropia. The purpose of this study is to evaluate the surgical outcomes of unilateral lateral rectus recession in the treatment of moderate-angle exotropia (≤ 25 PD (prism diopters)) in children. Methods The charts of all patients younger than 12 years of age with moderate-angle exotropia (up to 25 PD) who were operated during the years 2006–2018 were retrospectively reviewed. Fifty-eight patients underwent unilateral lateral rectus recession and had a minimum follow up of 6 months. The angle of exotropia (PD) before and after surgery and the success rate were documented. Results Mean age at surgery was 6.4 ± 1.9 (range 3.5–11.0) years. Exotropia improved from a preoperative angle of 21.4 ± 4.0 PD to 3.5 ± 5.9 PD postoperatively (p < 0.001). Success rate, defined as deviation of ≤ 10 PD, was achieved in 86.2%. There were 2 (3.4%) cases of overcorrection (consecutive esotropia). There were no intra- or postoperative complications. The mean follow-up duration after surgery was 2.3 ± 1.7 years. Conclusions In children with moderate angle exotropia, good postoperative success rate was achieved by performing unilateral lateral rectus recession.

scholarly journals Relationship between Quadriceps Tendon Young’s Modulus and Maximum Knee Flexion Angle in the Swing Phase of Gait in Patients with Severe Knee Osteoarthritis

Medicina ◽  
2020 ◽  
Vol 56 (9) ◽  
pp. 437
Author(s):  
Bungo Ebihara ◽  
Takashi Fukaya ◽  
Hirotaka Mutsuzaki
Keyword(s):  
Young’S Modulus ◽  
Gait Speed ◽  
Knee Flexion ◽  
Young's Modulus ◽  
Quadriceps Tendon ◽  
Swing Phase ◽  
Flexion Angle ◽  
Knee Flexion Angle ◽  
Knee Oa ◽  
Analysis System

Background and objectives: Decreased knee flexion in the swing phase of gait can be one of the causes of falls in severe knee osteoarthritis (OA). The quadriceps tendon is one of the causes of knee flexion limitation; however, it is unclear whether the stiffness of the quadriceps tendon affects the maximum knee flexion angle in the swing phase. The purpose of this study was to clarify the relationship between quadriceps tendon stiffness and maximum knee flexion angle in the swing phase of gait in patients with severe knee OA. Materials and Methods: This study was conducted from August 2018 to January 2020. Thirty patients with severe knee OA (median age 75.0 (interquartile range 67.5–76.0) years, Kellgren–Lawrence grade: 3 or 4) were evaluated. Quadriceps tendon stiffness was measured using Young’s modulus by ShearWave Elastography. The measurements were taken with the patient in the supine position with the knee bent at 60° in a relaxed state. A three-dimensional motion analysis system measured the maximum knee flexion angle in the swing phase. The measurements were taken at a self-selected gait speed. The motion analysis system also measured gait speed, step length, and cadence. Multiple regression analysis by the stepwise method was performed with maximum knee flexion angle in the swing phase as the dependent variable. Results: Multiple regression analysis identified quadriceps tendon Young’s modulus (standardized partial regression coefficients [β] = −0.410; p = 0.013) and gait speed (β = 0.433; p = 0.009) as independent variables for maximum knee flexion angle in the swing phase (adjusted coefficient of determination = 0.509; p < 0.001). Conclusions: Quadriceps tendon Young’s modulus is a predictor of the maximum knee flexion angle. Clinically, decreasing Young’s modulus may help to increase the maximum knee flexion angle in the swing phase in those with severe knee OA.

scholarly journals Evaluation of a Brief Intervention to Improve the Nursing Care of Young Children in a High HIV and AIDS Setting

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Linda M. Richter ◽  
Tamsen J. Rochat ◽  
Celia Hsiao ◽  
Thembelihle H. Zuma
Keyword(s):  
Young Children ◽  
Well Being ◽  
Hiv And Aids ◽  
Child Interaction ◽  
Home Based ◽  
Care And Support ◽  
Nurse Burnout ◽  
Before And After ◽  
Infant Pain ◽  
Outcomes For Children

The HIV epidemic in South Africa is putting great strain on health services, including the inpatient care of young children. Caregivers and young children (107 pairs) and 17 nurses participated in an intervention to improve the care of young children in hospital in a high HIV and AIDS setting. The intervention addressed caregiver expectations about admission and treatment, responsive feeding, coping with infant pain and distress, assistance with medical procedures, and preparation for discharge and home care. Following a preparatory and piloting phase, measures of nurse burnout, caregiver physical and emotional well-being, and caregiver-child interaction were made before and after intervention. No changes were found between before and after intervention on assessments of caregiver wellbeing. However, mothers in the postintervention phase rated nurses as more supportive; mother-child interaction during feeding was more relaxed and engaged, and babies were less socially withdrawn. While the intervention proved useful in improving certain outcomes for children and their caregivers, it did not address challenging hospital and ward administration or support needed by caregivers at home following discharge. To address the latter need, the intervention has been extended into the community through home-based palliative care and support.

Ankle–foot orthosis with dorsiflexion resistance using spring-cam mechanism increases knee flexion in the swing phase during walking in stroke patients with hemiplegia

2020 ◽  
Vol 81 ◽  
pp. 27-32 ◽  
Author(s):  
Yusuke Sekiguchi ◽  
Dai Owaki ◽  
Keita Honda ◽  
Kenichiro Fukushi ◽  
Noriyoshi Hiroi ◽  
...  
Keyword(s):  
Knee Flexion ◽  
Swing Phase ◽  
Stroke Patients ◽  
Ankle Foot Orthosis ◽  
Cam Mechanism ◽  
Foot Orthosis

Phonetic Imitation by Young Children and Its Developmental Changes

2014 ◽  
Vol 57 (6) ◽  
pp. 2065-2075 ◽  
Author(s):  
Kuniko Nielsen
Keyword(s):  
Young Children ◽  
Picture Naming ◽  
Voice Onset Time ◽  
Onset Time ◽  
Naming Task ◽  
Age Effect ◽  
Third Graders ◽  
Developmental Changes ◽  
Phonological Development ◽  
Before And After

Purpose In the current study, the author investigated the developmental course of phonetic imitation in childhood, and further evaluated existing accounts of phonetic imitation. Method Sixteen preschoolers, 15 third graders, and 18 college students participated in the current study. An experiment with a modified imitation paradigm with a picture-naming task was conducted, in which participants' voice-onset time (VOT) was compared before and after they were exposed to target speech with artificially increased VOT. Results Extended VOT in the target speech was imitated by preschoolers and 3rd graders as well as adults, confirming previous findings in phonetic imitation. Furthermore, an age effect of phonetic imitation was observed; namely, children showed greater imitation than adults, whereas the degree of imitation was comparable between preschoolers and 3rd graders. No significant effect of gender or word specificity was observed. Conclusions Young children imitated fine phonetic details of the target speech, and greater degree of phonetic imitation was observed in children compared to adults. These findings suggest that the degree of phonetic imitation negatively correlates with phonological development.

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