Xue-Cheng Liu

Kinematic and kinetic evaluation of the ankle joint before and after tendo achilles lengthening in patients with spastic diplegia.

Fourteen patients, at a mean age of 9.1 years (range 4.1-16.6 years), who had spastic diplegic cerebral palsy were evaluated before and after tendo Achilles lengthening (TAL). Follow-up (by gait analysis) after TAL ranged from 8 to 30 months. A Vicon motion analysis system with six CCD cameras and two AMTI force plates provided three-dimensional measurements of joint motion and moments. The TAL procedure resulted in normal passive dorsiflexion of the ankle joint with the knee at 0 degrees of extension and 90 degrees of flexion, reduced plantarflexion during swing phase, and reduced premature plantarflexor moment. However, 10 degrees greater than normal dorsiflexion of the ankle joint during mid-stance phase was indicative of a mild calcaneal gait pattern. The TAL procedure improved lower extremity function as documented by both kinematic and kinetic analysis in cerebral palsy.

Upper limb function and brain reorganization after constraint-induced movement therapy in children with hemiplegia

Objective: The aims of this study were to (1) investigate the effectiveness of CIMT for children with hemiplegia, (2) determine the feasibility of using fMRI for describing brain activity patterns before and after CIMT and (3) describe changes in brain reorganization after CIMT in children with hemiplegia using fMRI. Design: Before and after study with one group. Methods: Ten children aged 7–14 years (M = 11.0, SD = 2.5) with hemiplegia received CIMT over a 2-week period using a before and after design. Clinical measures included the Melbourne Assessment of Unilateral Upper Limb Function, upper limb kinematics and parent questionnaire. Children were measured with fMRI before and after CIMT. Results: Findings showed that CIMT may be effective at improving upper limb function in some, but not all children; those children with a moderate degree of impairment seemed to benefit the most. fMRI findings correlated moderately with clinical measures. Conclusion: Although unique challenges with fMRI data collection exist for this population, it provides potentially valuable information to better understand mechanisms of change after interventions such as CIMT.

Additive fabrication of custom pedorthoses for clubfoot correction

Purpose – The purpose of this paper is to determine the most‐practical means of transforming computer‐aided‐design models of custom clubfoot pedorthoses into functional pedorthoses for testing on patients in a clinical trial.Design/methodology/approach – The materials used in conventional orthosis fabrication are not yet available for solid free‐form fabrication; therefore, to fabricate the pedorthoses, several approaches were considered, including direct manufacturing, additive‐based moulding, laser cutting of foam and combinations of several of these approaches.Findings – The chosen approach of additively manufacturing the custom hard shell, and moulding the polyurethane‐foam insert, resulted in accurate, durable and effective pedorthoses that fit well, and could be adjusted as needed. The pedorthoses that were produced are currently being tested on the respective patients for their improvement in mobility and degree of clubfoot correction, and will continue through early 2010.Practical implications – A...

Reliability of a functional classification system in the monitoring of patients with idiopathic scoliosis.

Study Design. Patients with scoliosis from 1999 to 2001 were monitored using radiographs and the Quantec Spinal Imaging System (Quantec) to validate the Functional Classification System (FCS) developed at Children’s Hospital of Wisconsin (CHW). Objective. To determine the accuracy of the FCS. Summary of Background Data. The authors evaluated different noninvasive ways of evaluating the scoliotic spine. The FCS was developed as a means to predict the degree of scoliotic curve. Methods. Consecutive scoliosis visits (543) seen at CHW between 1999 and 2001 for initial or follow-up examination were investigated; of them, 157 had an radiograph within 6 months of Quantec. Subjects were placed into groups based on Cobb Angles. FCS classifications were compared to Cobb angle groupings and calculated sensitivity and specificity. Pearson’s correlation coefficient was calculated for 39 subjects. Results. Sensitivity of the FCS for single curve groups ranged from 0.50 to 0.63 and specificity from 0.64 to 0.86. For double curve, both sensitivity and specificity ranged from 0.48 to 0.81. Pearson’s correlation was statistically significant (r = 0.45, P < 0.05). Conclusions. Sensitivity, specificity, and Pearson’s correlation coefficient reflect the reliability of the Quantec method. Therefore, the FCS can be considered as a reliable tool for monitoring the progression of scoliosis with reduced need of radiographs.

Insole-pressure distribution for normal children in different age groups.

Background In measuring plantar pressures during gait, earlier methods have used a platform system that does not take into account the interactions feet have with orthotics and shoe wearing. The purpose of the study was to provide normal insole plantar pressure parameter data during stance phase using the Pedar pressure insole system. Methods Twenty-nine normal children, age 6 to 16 years, were recruited and walked along the 25 m walkway at self-selected speeds. Patients were divided into 2 separate groups for statistical analysis—juniors (<12 y old) and teenagers (>13 y old). The pressure map was divided into 8 regions (masks) determined by anatomic landmarks and a total of 7 pressure parameters were analyzed of each mask. Results We did not detect significant differences in foot pressures between juniors and teenagers when regarding sex, or left and right feet for 7 parameters measured. Conclusions This normative data will provide a basis with which to more accurately assess pediatric pathologic foot deformities and to distinguish dynamic foot deformities from anatomic foot deformities. The Level of Evidence Level II.

MRI pathoanatomy study of congenital vertical talus.

Background Prior reports regarding the pathologic anatomy for congenital vertical talus have noted some disagreement as to which elements of the pathologic anatomy are consistently present. The purpose of his study is to evaluate the 3-dimensional morphologic changes and pathoanatomy of the congenital vertical talus using magnetic resonance imaging. Methods Nine patients with congenital vertical talus (ranging from 5 mo-11 y) underwent magnetic resonance imaging of both feet. A foot and ankle coil was used for the 1.5 T system. The protocol consisted of T1-weighted spin echo sequence image and T2-weighted fast spin echo sequence image in the sagittal, coronal, and axial planes. Slice thickness ranged from 3 to 4 mm with 0 to 1.0 mm interspace thickness. A descriptive analysis was performed based upon the T1-weighted image by physicians. Results At the level of the talonavicular joint, the navicular was seen significantly subluxed dorsally with associated wedging of the navicular. At the level of the calcaneocuboid joint, often there was a significant dorsal subluxation of the cuboid in relation to the calcaneus. Lateral obliquity of the calcaneocuboid joint could be present to varying degrees. The anterior calcaneus was significantly laterally displaced in relation to the talar head with an element of lateral translation and eversion of the calcaneus at the subtalar joint. Distal cavus at the cuneiform-first metatarsal joint was observed in 5 patients. Conclusions This study suggests that there is significant pathology at the level of subtalar joint in congenital vertical talus. In addition to satisfactory reduction of the talonavicular joint, methods to ensure realignment of the calcaneus under the talus may be a crucial component of deformity correction and to prevent recurrence of deformity. Level of Evidence A Level III diagnostic study using normal pediatric foot anatomy in magnetic resonance imaging as a reference.

A New Method in the Design of a Dynamic Pedorthosis for Children With Residual Clubfoot

Clubfoot is a common pediatric orthopaedic deformity. Despite the popularity of Ponseti’s method and night splints such as the Denis–Browne method, there is still an 11–47% rate of deformity relapse reported in the literature. The technique to make traditional orthotics is dependent on a nonweight-bearing casting or foot imprint. These splints outdate clinical treatment trends and only apply to patients who are of nonwalking age. This study shows that a new procedure utilizing computer aided design and the finite element method can be employed to develop a customized weight-bearing dynamic orthotic. In addition, the plantar pressure distribution and the trajectory of the center of this pressure distribution are used to design the orthotic. It is shown that the trajectory of the center of pressure, traditionally used in gait analysis, can be used not only to quantify the severity of the foot deformity but to design a custom orthotic as well. Also, the new procedure allows the custom orthotic to be designed and analyzed within a day. The new orthotic design is composed of soft foam interior layers and a polymer supportive exterior layer. It is proved that rapid prototyping technologies employing selective laser sintering can be used to construct these layers to produce a custom orthotic within a 24 h time frame.

A line of zebrafish with development of abnormal spinal curvatures

Methods Potential founder fish with spinal curvatures were outcrossed with a wild type zebrafish line (AB) and the resulting siblings (F1 generation) crossed and the offspring (F2 generation) examined for signs of spinal curvature beginning at 14 days post fertilization (dpf). Spinal curvatures of the affected fish were visualized using either a Faxitron or by Alizarian red staining of the skeletons and the curvature measured from the resulting images in the thoracic, thoracolumbar, or lumbar regions. Affected and normal zebrafish were fixed, embedded, section and stained with hemotoxylin and eosin.

Hatha Yoga for Pediatric Obesity: A Pilot Study

Objective: Little is known about the benefits of yoga for pediatric obesity, and no studies have examined the benefits of yoga for physical activity in either adults or children. The purpose of this pilot study was to examine whether Hatha yoga would improve overall, physical and psychosocial functioning in youth with severe obesity. We also sought to determine whether participants would increase the vigor of, and time spent in, physical activity. Methods: This study utilized a pre-test/post-test design. Sixteen youth with severe obesity completed an 8 week Hatha yoga intervention involving fifteen, 60-minute classes. Physical and psychosocial functioning, fitness and state-anxiety were assessed at baseline and post-intervention; parents completed proxy-reports of physical and psychosocial functioning at both time points. To assess physical activity, participants wore an Actical Accelerometer for 7 days pre and post-yoga. Results: Significant improvements were found in: Overall, Physical and Psychosocial functioning, back and hamstring flexibility, and state-anxiety. Changes in the proportion of time spent in both light and moderate levels of physical activity were marginally significant. Although 3 tests of fitness, and time spent in physical activity did not improve significantly, trends were in the expected direction. Conclusions: Youth with severe obesity may benefit from a Hatha yoga intervention. Yoga may also offer a way to engage in physical activity that is not precluded by bodily pain.

Foot and ankle joint movements inside orthoses for children with spastic CP

We compared the ankle joint and foot segment kinematics of pediatric cerebral palsy (CP) participants walking with and without orthoses. A six segment foot model (6SF) was used to track foot motion. Holes were cut in the study orthoses so that electromagnetic markers could be directly placed on the skin. The Hinged Ankle Foot Orthoses (HAFO) allowed a significant increase in ankle dorsiflexion as compared to the barefoot condition during gait, but significantly constrained sagittal forefoot motion and forefoot sagittal range of motion (ROM) (p < 0.01), which may be detrimental. The Solid Ankle Foot Orthoses (SAFO) constrained forefoot ROM as compared to barefoot gait (p < 0.01). The 6SF model did not confirm that the SAFO can control excessive plantarflexion for those with severe plantarflexor spasticity. The supramalleolar orthosis (SMO) significantly (p < 0.01) constrained forefoot ROM as compared to barefoot gait at the beginning and end of the stance phase, which could be detrimental. The SMO had no effects observed in the coronal plane.