| 1. |
- Balta, Diletta, et al.
(author)
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A Model-Based Markerless Protocol for Clinical Gait Analysis Based on a Single RGB-Depth Camera: Concurrent Validation on Patients With Cerebral Palsy
- 2023
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In: IEEE ACCESS. - 2169-3536. ; 11, s. 144377-144393
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Journal article (peer-reviewed)abstract
- Clinical gait analysis is a diagnostic tool often used for identifying and quantifying gait alterations in cerebral palsy (CP) patients. To date, 3D clinical gait analysis protocols based on motion capture systems featuring multiple infrared cameras and retroreflective markers to be attached to the subject's skin are considered the gold standard. However, the need for fully dedicated personnel and space in addition to the inconvenient requirement of multiple markers attached on the patient's body limit their use in the clinical practice. To shorten the time necessary to setup the patient and to limit his/her discomfort motion tracking performed using markerless technologies may offer a promising alternative to marker-based motion capture. This study aims at proposing and validating on 18 CP patients, an original markerless clinical gait analysis protocol based on a single RGB-D camera. Accuracy and reliability of the spatial-temporal parameters and sagittal lower limb joint kinematics were assessed based on a 3D marker-based clinical gait analysis protocol. The smallest percent mean absolute errors were obtained for stride duration (2%), followed by the step and stride length (2.2% and 2.5%, respectively) and by gait speed (3.1%). The average angular offset values between the two protocols were 8 degrees for the ankle, 6 degrees for the knee and 7 degrees for the hip joint. The smallest root mean square error values were found for the knee joint kinematics (3.2 degrees), followed by the hip (3.5 degrees) and the ankle (4.5 degrees). Both protocols showed a good-to-excellent reliability. Thus, this study demonstrated the technical validity of a markerless single-camera protocol for clinical gait analysis in CP population. The dataset containing markerless data from 10 CP patients along with the MATLAB codes have been made available.
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| 2. |
- Cocchi, Ilaria, et al.
(author)
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A 2D markerless gait analysis protocol to estimate the sagittal joint kinematics of children with cerebral palsy
- 2019
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In: 2019 IEEE 23RD INTERNATIONAL SYMPOSIUM ON CONSUMER TECHNOLOGIES (ISCT). - : IEEE. - 9781728135700 ; , s. 192-196
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Conference paper (peer-reviewed)abstract
- The quantitative analysis of human movement provides a deep understanding of the pathophysiological mechanisms underlying locomotion. The traditional marker-based stereo-photogrammetric systems and clinical protocols for motion analysis, although very accurate, have a number of disadvantages that limit their use to large clinical facilities. Among the disadvantages is the use of markers on the body, which can make the patient uneasy, especially children with cerebral palsy. To overcome the limitations of the marker-based stereophotogrammetry and to guarantee accuracy, reproducibility and usability of the measurement, a new markerless protocol is introduced, which, estimates the lower limb sagittal joint kinematics from RGB video images combined with measurements from an infrared depth (D) sensor. The validity of the markerless protocol is demonstrated by comparing the estimates obtained, with those resulting from the application of a common protocol applied to marker-based measurements. The joint kinematics patterns obtained from the ML protocol and the one of reference showed a good agreement after removing the angular offsets with RMSD values between 3.5 and 5 degrees for all joints and R values between 0.8 and 1. The interpretation of the differences found in this study should be treated carefully since they are the results not only of different measurement systems but also of different protocols (2D vs 3D). The proposed protocol for the estimation of the 2D joint kinematics of the lower limbs from RGB-D sensor data is a promising low-cost and simple solution for monitoring children with cerebral palsy.
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| 3. |
- Flinck, Marianne, et al.
(author)
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Biomechanical comparison of semi-rigid pediatric locking nail versus titanium elastic nails in a femur fracture model.
- 2015
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In: Journal of children's orthopaedics. - : SAGE Publications. - 1863-2521 .- 1863-2548. ; 9:1, s. 77-84
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Journal article (peer-reviewed)abstract
- The treatment for length-unstable diaphyseal femur fractures among school-age children is commonly intramedullary elastic nails, with or without end caps. Another possible treatment is the semi-rigid pediatric locking nail (PLN). The purpose of this biomechanical study was to assess the stability of a length-unstable oblique midshaft fracture in a synthetic femur model stabilized with different combinations of intramedullary elastic nails and with a PLN.Twenty-four femur models with an intramedullary canal diameter of 10.0 mm were used. Three groups with various combinations of titanium elastic nails (TEN) with end caps and one group with a PLN were tested. An oblique midshaft fracture was created, and the models underwent compression, rotation, flexion/extension, and a varus/valgus test, with 50 and 100 % of the forces generated during walking in corresponding planes.We present the results [median (range)] from 100 % loading during walking. In axial compression, the PLN was less shortened than the combination with two 4.0-mm TEN [by 4.4 (3.4-5.4) mm vs. 5.2 (4.8-6.6) mm, respectively; p = 0.030]. No difference was found in shortening between the PLN and the four 3.0-mm TEN [by 7.0 (3.3-8.4) mm; p = 0.065]. The two 3.0-mm TEN did not withstand the maximum shortening of 10.0 mm. In external rotation, the PLN rotated 12.0° (7.0-16.4°) while the TEN models displaced more than the maximum of 20.0°. No model withstood a maximal rotation of 20.0° internal rotation. In the four-point bending test, in the coronal and the sagittal plane, all combinations except the two 3.0-mm TEN in extension withstood the maximum angulation of 20.0°.PLN provides the greatest stability in all planes compared to TEN models with end caps, even though the difference from the two 4.0-mm or four 3.0-mm TEN models was small.
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| 4. |
- Flinck, Marianne, et al.
(author)
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Leg length discrepancy after skeletal maturity in patients treated with elastic intramedullary nails after femoral shaft fractures in childhood
- 2022
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In: Journal of Childrens Orthopaedics. - : SAGE Publications. - 1863-2521 .- 1863-2548. ; 16:4, s. 276-284
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Journal article (peer-reviewed)abstract
- Purpose: The purpose was to study radiographic and perceived leg length discrepancy after skeletal maturity in patients treated for femoral shaft fractures with elastic stable intramedullary nails in childhood. Methods: Thirty-five adults underwent standing radiographs and answered a questionnaire regarding perception of leg length discrepancy. Demographic data, fracture characteristics, angulation, stability of fixation, and callus formation, at time of fracture, were assessed. Results: Mean age at fracture was 10.2 (4.9-16.7) years, and mean follow-up time was 11.1 (3.8-16.8) years. In 8 of 35 participants, the fractured limb was 11-15 mm longer than the non-fractured, and in 16, 1-10 mm longer. In eight participants, the fractured limb was 1-10 mm shorter than the non-fractured, and in three participants, 12-23 mm shorter. The younger the child, the greater the lengthening (R-s = -0.49, p = 0.003). The greater the femoral angulation at time of fracture, the greater the shortening (R-s = 0.42, p = 0.013). There was no significant correlation between stability of fixation or callus formation 1 month postoperatively and radiographic leg length discrepancy after skeletal maturity. Fourteen (40%) had perception of leg length discrepancy at follow-up, of whom eight had a radiographic leg length discrepancy of 10-24 mm. Conclusion: Treatment with elastic stable intramedullary nail of femoral shaft fracture in childhood may result in radiographic leg length discrepancy. Younger children were more prone to lengthening and should possibly be assessed before skeletal maturity. The degree of fracture stability or callus formation at the time of fracture did not significantly affect leg length discrepancy. Perception of leg length discrepancy was not necessarily associated with a radiographic leg length discrepancy (>= 10 mm).
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| 5. |
- Flinck, Marianne, et al.
(author)
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Recovery of Gait in Children and Adolescents After Pediatric Femoral Shaft Fracture Treated With Intramedullary Nail Fixation: A Longitudinal Prospective Study.
- 2024
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In: Journal of pediatric orthopedics. - 1539-2570. ; 44:1, s. 1-6
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Journal article (peer-reviewed)abstract
- Femoral shaft fractures in school-aged children are commonly treated with intramedullary nail fixation. Outcomes such as time to healing, alignment and non-union, leg length discrepancy, and refractures, and other complications are often reported based on radiographic findings. There are limited reports on physical function, including objective quantitative measures. The aim was to study the progress and recovery of gait after femoral shaft fracture in children and adolescents.Inclusion criteria were individuals 6 to 16 years of age with a femoral shaft fracture treated with intramedullary nails. Exclusion criteria were pathologic fractures and other physical impairments or injuries that influenced gait.At 6 and 12 weeks, assessments of mobilization and weight bearing were performed at clinical hospital follow-ups.At 3, 6, 9, and 12 months, physical examinations of passive range of motion, stair walking, and three-dimensional gait analysis, including temporospatial, movement (kinematics), and force (kinetics) data, were performed.Seventeen participants, with a median of 9.2 (interquartile range 6.5 to 11.3) years of age were included. At 6 weeks, 14 of 16 (88%) used walking aids and at twelve weeks, 25% did. Sixty-nine percent could walk up and down stairs at 6 weeks and 100% at 12 weeks. At 3 months, 3 participants walked with a speed below 100cm/second and had clear deviations in gait pattern compared with the control group. Three participants had no deviations in gait patterns at 3 months. Gait patterns had normalized in most participants at 6 months. Hip and knee extension moments were decreased up to 6 months compared with the control group. Hip extensor muscle work was increased on the fractured side compared with the control group.Early recovery, between 6 and 12 weeks postoperatively, was noted in basic performance tests after femoral shaft fractures in children and adolescents. Three-dimensional gait analysis revealed normalization of gait patterns at 6 months. Information on the expected time and degree of recovery of physical function could guide the rehabilitation process.Level III.
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| 6. |
- Hermanson, Maria, et al.
(author)
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Head-shaft angle is a risk factor for hip displacement in children with cerebral palsy.
- 2015
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In: Acta Orthopaedica. - : Medical Journals Sweden AB. - 1745-3682 .- 1745-3674. ; 86:2, s. 229-232
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Journal article (peer-reviewed)abstract
- Background and purpose - Hip dislocation in children with cerebral palsy (CP) is a common and severe problem. The Swedish follow-up program for CP (CPUP) includes standardized monitoring of the hips. Migration percentage (MP) is a widely accepted measure of hip displacement. Coxa valga and valgus of the femoral head in relation to the femoral neck can be measured as the head-shaft angle (HSA). We assessed HSA as a risk factor for hip displacement in CP. Patients and methods - We analyzed radiographs of children within CPUP from selected regions of Sweden. Inclusion criteria were children with Gross Motor Function Classification System (GMFCS) levels III-V, MP of < 40% in both hips at the first radiograph, and a follow-up period of 5 years or until development of MP > 40% of either hip within 5 years. Risk ratio between children who differed in HSA by 1 degree was calculated and corrected for age, MP, and GMFCS level using multiple Poisson regression. Results - 145 children (73 boys) with a mean age of 3.5 (0.6-9.7) years at the initial radiograph were included. 51 children developed hip displacement whereas 94 children maintained a MP of < 40%. The risk ratio for hip displacement was 1.05 (p < 0.001; 95% CI 1.02-1.08). When comparing 2 children of the same age, GMFCS level, and MP, a 10-degree difference in HSA results in a 1.6-times higher risk of hip displacement in the child with the higher HSA. Interpretation - A high HSA appears to be a risk factor for hip displacement in children with CP.
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| 7. |
- Holmdahl, Per, et al.
(author)
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Continued growth after fixation of slipped capital femoral epiphysis.
- 2016
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In: Journal of children's orthopaedics. - : SAGE Publications. - 1863-2521 .- 1863-2548. ; 10:6, s. 643-650
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Journal article (peer-reviewed)abstract
- When treating slipped capital femoral epiphysis (SCFE), a smooth pin with a hook or a short threaded screw can be used to allow further growth, which could be important to prevent the development of impingement and early arthritis. The purpose of this investigation was to measure growth in three dimensions after fixation of SCFE.Sixteen participants with unilateral SCFE, nine girls and seven boys with a median age of 12.0years (range 8.4-15.7years), were included. The slipped hip was fixed with a smooth pin with a hook, and the non-slipped hip was prophylactically pinned. At the time of surgery, tantalum markers were installed bilaterally on each side of the growth plate through the drilled hole for the pin. Examination with radiostereometric analysis (RSA) was performed postoperatively and at 3, 6 and 12months. The position of the epiphysis in relation to the metaphysis was calculated.At 12months, the epiphysis moved caudally, median 0.16mm and posteriorly 2.28mm on the slipped side, in comparison to 2.28 cranially and 0.91mm posteriorly on the non-slipped side, p=0.003 and p=0.030, respectively. Both slipped and non-slipped epiphysis moved medially, 1.52 and 1.74mm, respectively. A marked variation in the movement was noted, especially on the slipped side.The epiphysis moved in relation to the metaphysis after smooth pin fixation, both on the slipped side and on the prophylactically fixed non-slipped side, implying further growth. The RSA method can be used to understand remodelling after 'growth-sparing' fixation of SCFE.
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| 8. |
- Klets, Olesya, et al.
(author)
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Comparison between a subject-specific and a scaled generic musculoskeletal model of the lower extremities in a subject with unilateral cerebral palsy
- 2011
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In: Clinical Biomechanics. - 0268-0033 .- 1879-1271.
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Journal article (other academic/artistic)abstract
- The purpose of this paper was to develop methods to build a subject-specific musculoskeletal model of the lower extremities based on MRIs of a subject with unilateral CP, and to determine whether a scaled generic musculoskeletal model is accurate enough to characterize MTLs and MALs of 70 muscles in both lower limbs during gait in a subject with unilateral cerebral palsy. We found, that the generic models produced accurate values for changes in MTL during gait for almost all muscles, except adductor longus, adductor magnus, adductor brevis, quadratus femoris, pectineus, extensor digitorum longus, soleus, lateral gastrocnemius, and medial gastrocnemius. MALs computed from the scaled generic model, however, differed considerably from those computed from the subject-specific model. Upon comparison of hip, knee and ankle MALs in affected and non-affected sides of the lower extremities, the scaled generic model generally failed to identify level arm dysfunction in the subject with unilateral CP
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| 10. |
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