Publications by authors named "Ernst B Zwick"

The onset and timing of the growth of children and adolescents occurs with considerable variability in cohorts of the same chronological age. The musculoskeletal system changes in proportion over time, and lever-arm changes, altered individual flexibility, and strength lead to age-specific injury patterns in youth sports. In sports, juniors are commonly grouped according to their chronological age.

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The aim of this study was to analyze gait function and muscular strength on donor site after harvesting of a vascularized fibula osteoseptocutaneous flap. Nine patients with a mean follow-up of 33 months (range, 7-59) and a mean resection length of the middle portion of the fibula of 18.0 cm (range, 14.

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Purpose: Legg-Calvé-Perthes disease (LCP) severely limits the range of hip motion and hinders a normal gait. Loading of the hip joint is a major consideration in LCP treatment. The aim of this study was to evaluate gait patterns in LCP and identify gait modifications to decrease the load on the affected hip.

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This study compared the long-term outcome of single-event multilevel surgery in spastic diplegic cerebral palsy (CP) on the basis of sex. We hypothesized that boys would have a worse outcome than girls. Thirty-four children (19 boys and 15 girls) with diplegic spastic CP and a minimal follow-up of 10 years were included.

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Hemimelia of the lower limb belongs to the group of congenital deficiency disorders. The clinical spectrum ranges from minimal shortening of the long bones to severe deficiencies of the extremities. Several etiologies, such as X-rays or drugs, have been implicated to be responsible for hemimelia.

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Aim: Information on the timing and long-term outcome of single-event multilevel surgery in children with bilateral spastic cerebral palsy (CP) walking with flexed knee gait is limited. Based on our clinical experience, we hypothesized that older children with bilateral spastic CP would benefit more from single-event multilevel surgery than younger children. Moreover, any improvement in older children could be maintained with fewer additional surgery events.

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Bradykinesia represents one of the cardinal and most incapacitating features of Parkinson's disease (PD). In this context, investigating the cerebral control mechanisms for limb movements and defining the associated functional neuroanatomy is important for understanding the impaired motor activity in PD. So far, most studies have focused on motor control of upper limb movements in PD.

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Objectives: To detect outcome measures that could help differentiate between dynamic and fixed equinus (FEQ) deformities in children with cerebral palsy, and secondary, to describe the function of the gastrocnemius and soleus (SOL) muscles when either dynamic triceps surae tightness or FEQ contracture is present.

Design: A group-comparison study.

Setting: Gait analysis laboratory.

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The aim of the study was to confirm the hypothesis of the influence of the dynamic and fixed equinus deformity on the timing of knee recurvation (hyperextension). According to our hypothesis, dynamic equinus is linked to early and fixed equinus and to late knee hyperextension. A group 35 children with cerebral palsy (47 lower limbs) was divided into two subgroups according to the timing of maximum knee hyperextension.

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Hyperextension of the knee in stance (knee recurvatum) is a common disorder in patients with spastic cerebral palsy (CP). A group 35 children with CP (47 lower limbs) was divided into two subgroups according to the timing of maximum knee extension during the stance phase of gait. Gait analysis and musculoskeletal modelling data were compared with a control group of 12 normally developing children.

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Objective: To compare time-distance, kinematic, and kinetic gait parameters in patients with idiopathic Parkinson's disease (PD) off dopaminergic therapy with a group of healthy control subjects.

Design: A group-comparison study.

Setting: Gait analysis laboratory.

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Unlabelled: The Ponseti method of treatment for congenital clubfeet has gained widespread clinical acceptance. We have used manipulation, serial casting, and surgery to treat congenital clubfeet for almost 3 decades. Considering the Ponseti method of treatment to replace our traditional treatment method, we conducted a randomized, controlled trial evaluating the short-term outcome of the two treatment protocols.

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Background: This study aimed to evaluate the incidence and severity of pin tract infections in a series of pediatric trauma patients.

Methods: All pediatric trauma patients with external fixation who were treated at our institution between 1998 and 2003 were included. The charts of 30 children (20 males; 10 females; mean age, 13.

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This paper reviews the application of continuous recurrent neural networks with time-varying weights to pattern recognition tasks in medicine. A general learning algorithm based on Pontryagin's maximum principle is recapitulated, and possibilities of improving the generalization capabilities of these networks are given. The effectiveness of the methods is demonstrated by three different real-world examples taken from the fields of anesthesiology, orthopedics, and radiology.

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Eleven children with hemiplegic or an asymmetric diplegic cerebral palsy who had a preoperative leg length discrepancy of more than 2.5 cm underwent gait improvement surgery which included leg length equalisation. Sagittal plane kinematics and kinetics before and about 3 years after surgery for the lengthened limb and contralateral limb were evaluated.

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Recently, two missense mutations (N88S, S90L) in the Berardinelli-Seip congenital lipodystrophy gene have been identified in autosomal dominant distal hereditary motor neuropathy and Silver syndrome. We report the phenotypic consequences of the N88S mutation in 90 patients of 1 large Austrian family and two unrelated German families. Variation in the clinical and electrophysiological phenotype enabled us to distinguish six subtypes.

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In this study a generalised dynamic neural network (GDNN) was designed to process gait analysis parameters to evaluate equinus deformity in ambulatory children with cerebral palsy. The aim was to differentiate dynamic calf muscle tightness from fixed muscle contracture. Patients underwent clinical examination and had instrumented gait analysis before evaluating their equinus under anaesthesia and muscle relaxation at the time of surgery to improve gait.

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This work addresses the problem of improving the generalization capabilities of continuous recurrent neural networks. The learning task is transformed into an optimal control framework in which the weights and the initial network state are treated as unknown controls. A new learning algorithm based on a variational formulation of Pontrayagin's maximum principle is proposed.

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This study evaluated the effects of medial hamstring lengthening on gait in patients with diplegic cerebral palsy. A group of patients who underwent medial hamstring lengthening and distal rectus transfer was compared to a group of patients who underwent intramuscular psoas lengthening as well. Patients who underwent a psoas lengthening showed an increased anterior pelvic tilt and a tendency towards genu recurvatum, features that could indicate postoperative hamstring weakness.

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The purpose of this study was to evaluate hip and pelvis rotations in groups of hemiplegic and diplegic children before and after surgical correction of fixed internal rotation deformity of the hip. Twenty-two children with cerebral palsy (eight diplegia, 14 hemiplegia) having fixed internal rotation deformity at the hip were treated by multilevel surgery which included derotation osteotomy of the femur. Evaluation was done before and at a mean of 3.

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