Adam Graf - Academia.edu (original) (raw)

Papers by Adam Graf

2022 IEEE-EMBS International Conference on Biomedical and Health Informatics (BHI)

The Bone & Joint Journal, 2013

Van Nes rotationplasty may be used for patients with congenital proximal focal femoral deficiency... more Van Nes rotationplasty may be used for patients with congenital proximal focal femoral deficiency (PFFD). The lower limb is rotated to use the ankle and foot as a functional knee joint within a prosthesis. A small series of cases was investigated to determine the long-term outcome. At a mean of 21.5 years (11 to 45) after their rotationplasty, a total of 12 prosthetic patients completed the Short-Form (SF)-36, Faces Pain Scale-Revised, Harris hip score, Oswestry back pain score and Prosthetic Evaluation Questionnaires, as did 12 age- and gender-matched normal control participants. A physical examination and gait analysis, computerised dynamic posturography (CDP), and timed ‘Up & Go’ testing was also completed. Wilcoxon Signed rank test was used to compare each PFFD patient with a matched control participant with false discovery rate of 5%.There were no differences between the groups in overall health and well-being on the SF-36. Significant differences were seen in gait parameters i...

Abstracts of the 27th Annual Meeting of the GCMAS

Studies in health technology and informatics, 2010

This study uses experimental data acquired from adolescents with idiopathic scoliosis to assess t... more This study uses experimental data acquired from adolescents with idiopathic scoliosis to assess their postural control during quiet standing before and after posterior spinal fusion. Statistically significant differences were seen when comparing the pre- and post-surgical measures of balance calculated from data for three different test conditions.

License, which permits unrestricted use, distribution, and reproduction in any medium, provided t... more License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. There is minimal research of upper extremity joint dynamics during pediatric wheelchair mobility despite the large number of children using manual wheelchairs. Special concern arises with the pediatric population, particularly in regard to the longer duration of wheelchair use, joint integrity, participation and community integration, and transitional care into adulthood. This study seeks to provide evaluation methods for characterizing the biomechanics of wheelchair use by children with spinal cord injury (SCI). Twelve subjects with SCI underwent motion analysis while they propelled their wheelchair at a self-selected speed and propulsion pattern. Upper extremity joint kinematics, forces, and moments were computed using inverse dynamics methods with our custommodel.The glenohumeral joint displayed the largest average range ofmotion (ROM) at 47.1 ∘ in ...

Radiopaedia.org, 2020

Proximal focal femoral deficiency (PFFD) is a developmental disorder of the proximal segment of t... more Proximal focal femoral deficiency (PFFD) is a developmental disorder of the proximal segment of the femur and of acetabulum resulting in shortening of the affected limb and impairment of the function. It is a spectrum of congenital osseous anomalies characterized by a deficiency in the structure of the proximal femur. The diagnosis is often made by radiological evaluation which includes identification and description of PFFD and evaluation of associated limb anomalies by plain radiographs. Contrast arthrography or Magnetic Resonance Imaging is indicated when radiological features are questionable and to disclose the presence and location of the femoral head and any cartilagenous anlage. The disorder is more commonly unilateral and is apparent at birth. However, bilateral involvement is rarely seen. Therapy of the disorder is directed towards satisfactory ambulation and specific treatment depending on the severity of dysplasia.

2008 30th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 2008

This study presents initial results from a bi-planar model used to investigate the neurological f... more This study presents initial results from a bi-planar model used to investigate the neurological factors affecting balance deficits in children with diplegic cerebral palsy (CP). The model uses an inverted pendulum to describe sway in both the anteroposterior (AP) and mediolateral (ML) planes. The study presents Center of Pressure (COP) data from 17 children diagnosed with spastic diplegic CP using two standard AMTI force plates. Sway metrics in the time and frequency domains in the AP and ML planes were calculated and compared to simulations produced by the model. The proposed bi-planar model successfully reproduced sway signals acquired from experimental (clinical) data.

homepages.cae.wisc.edu

The incidence of allergy and asthma is an ever-increasing health problem in our world today. A gr... more The incidence of allergy and asthma is an ever-increasing health problem in our world today. A great deal of research is currently being directed toward determining the cause of these diseases. Lung tissue research at the cellular level deals with three individual cells; the ...

Journal of Bone and Joint Surgery-british Volume, 2013

Van Nes rotationplasty is a treatment option for individuals with congenital proximal focal femor... more Van Nes rotationplasty is a treatment option for individuals with congenital proximal focal femoral deficiency (PFFD), in which the extremity is surgically rotated to utilize the ankle and foot as a functional knee joint in a prosthesis. This case control study was done to determine the long-term function and quality of life (QOL) outcomes of these individuals. Twelve prosthetic participants (PFFD Group) and 12 control participants (Control Group) completed SF-36, Faces Pain Scale-Revised, Harris Hip Score, Oswestry back pain score and Prosthetic Evaluation Questionnaire© .Lower extremity physical exam, gait analysis, computerized dynamic posturography (CDP), and Timed 'Up & Go' testing was also completed. Wilcoxon Signed rank test used to compare each PFFD participant to the matched Control participant with false discovery rate of 5%. There were no differences between the Groups in overall health and well-being on the SF-36. Significant differences were seen in gait parameters in the PFFD Group. Using CDP, the PFFD Group showed decreased symmetry in stance, and reduced end point and maximum excursions. Individuals who underwent Van Nes rotationplasty showed a high level of function and QOL at long-term follow up, but presented with significant differences in gait and posturography parameters compared to the Control Group.

Journal of Clinical Orthopaedics and Trauma, 2021

Lateral column lengthening (LCL) is commonly performed on children and adolescents with cerebral ... more Lateral column lengthening (LCL) is commonly performed on children and adolescents with cerebral palsy (CP) for correction of pes planovalgus (PPV). There are limited reports of the long-term outcomes of this procedure. The purpose of this study was to examine the long-term results of LCL for correction of PPV in individuals with CP by evaluating subjects when they had transitioned to adulthood and were entering the workforce. Clinical assessments, quantitative gait analysis including the Milwaukee Foot Model (MFM) for segmental foot kinematics, and patient reported outcomes were collected from 13 participants with CP treated with LCL for PPV in childhood (average age 24.4 ± 5.7 years, average 15.3 ± 8.5 years since LCL). Additionally, 27 healthy adults average age 24.5 ± 3.6 years functioned as controls. Strength and joint range of motion were reduced in the PPV group (p < 0.05). Sixty nine percent showed operative correction of PPV based on radiologic criteria. Gait analysis showed reduced walking speed and stride length, as well as midfoot break and residual forefoot abduction. Patient reported outcomes indicated that foot pain was not the only factor that caused limited activity and participation. LCL surgery for PPV in childhood resulted in long-term operative correction. Decreased ankle passive range of motion and strength, subtalar joint arthritic changes, inefficient and less stable ambulation, and problems with participation (difficulties in physical function, education, and employment) were observed in the long-term. This study identified postoperative impairments and limitations to guide future clinical decision-making. These results provide clinicians and researchers the common residual and recurrent issues for these individuals as they age. The inclusion of contextual factors that influence the disease and impairments can equip these individuals with enhanced skills they need as they transition into adulthood.

Spine Deformity, 2018

This paper is NOT THE PUBLISHED VERSION; but the author's final, peer-reviewed manuscript. The pu... more This paper is NOT THE PUBLISHED VERSION; but the author's final, peer-reviewed manuscript. The published version may be accessed by following the link in th citation below.

2014 36th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 2014

While much work is being done evaluating the upper extremity joint dynamics of adult manual wheel... more While much work is being done evaluating the upper extremity joint dynamics of adult manual wheelchair propulsion, limited work has examined the pediatric population of manual wheelchair users. Our group used a custom pediatric biomechanical model to characterize the upper extremity joint dynamics of 12 children and adolescents with spinal cord injury (SCI) during wheelchair propulsion. Results show that loading appears to agree with that of adult manual wheelchair users, with the highest loading primarily seen at the glenohumeral joint. This is concerning due to the increased time of wheelchair use in the pediatric population and the impact of this loading during developmental years. This research may assist clinicians with improved mobility assessment methods, wheelchair prescription, training, and longterm care of children with orthopaedic disabilities.

2012 Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 2012

Current methods for evaluating upper extremity (UE) dynamics during pediatric wheelchair use are ... more Current methods for evaluating upper extremity (UE) dynamics during pediatric wheelchair use are limited. We propose a new model to characterize UE joint kinematics and kinetics during pediatric wheelchair mobility. The bilateral model is comprised of the thorax, clavicle, scapula, upper arm, forearm, and hand segments. The modeled joints include: sternoclavicular, acromioclavicular, glenohumeral, elbow and wrist. The model is complete and is currently undergoing pilot studies for NOT THE PUBLISHED VERSION; this is the author's final, peer-reviewed manuscript.

Critical Reviews™ in Physical and Rehabilitation Medicine, 2011

2009 Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 2009

This study examines the postural stability of children with idiopathic scoliosis, using experimen... more This study examines the postural stability of children with idiopathic scoliosis, using experimental data and a model of sway that includes mediolateral (ML) and anterioposterial (AP) components. The experimental data includes center of pressure (COP) measurements calculated from data acquired using two Advanced Medical Technology, Inc. (AMTI) force plates. Sway metrics are computed and compared with the model simulation, which successfully reproduced the clinical data from 16 children with scoliosis and 20 typically-developing children. This study is part of the first phase of a multi-year study designed to systematically assess whether fusing the spine to L4 in children with scoliosis has a significant impact on physical function and quality of life.

2011 Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 2011

Current methods for the evaluation of upper extremity dynamics during wheelchair mobility in chil... more Current methods for the evaluation of upper extremity dynamics during wheelchair mobility in children are limited. The goal of this study was to characterize upper extremity joint kinematics during wheelchair mobility. A 3-D biomechanical model of the upper extremities is presented for kinematic assessment of manual wheelchair propulsion in children with Spinal Cord Injury (SCI). The bilateral upper extremity model consists of the thorax, upper arms, forearms, and hands. The model was applied to thirteen (13) children with SCI. Joint angles and joint ranges of motion of the shoulders, elbows, and wrists were quantified. Peak joint motions during the stroke cycle were compared between right and left sides for further insight to mobility patterns. This work will provide insight to be used in future kinetic studies of wheelchair mobility.

Journal of Experimental & Clinical Medicine, 2011

Background/Purpose Children with type 1 osteogenesis imperfecta (OI) present with abnormal gait c... more Background/Purpose Children with type 1 osteogenesis imperfecta (OI) present with abnormal gait characteristics, including reduced power generation during pushoff. However, the exact biomechanical factors associated with reduced power generation are not clearly understood. The purpose of this study was to investigate the biomechanical factors associated with a reduction in ankle power generation in children with type 1 OI. Methods Twenty-four participants with type 1 OI (12.5 ± 3.6 years of age) and 24 typically developing children (12.4 ± 3.7 years of age) were evaluated. Three-dimensional gait analysis, isometric plantar flexion strength using dynamometry, and pedobarography were collected on each participant. Results were statistically compared between the groups and a correlation matrix analyzed the associations among the measures. Results Children with OI presented with weaker plantar flexors, reduced ankle power generation, and decreased sagittal plane ankle angular velocity during pushoff. However, they presented with similar moment arm distances and ground reaction force magnitudes as typically seen in developing children. There was a higher incidence of pes valgus, increased subarch angles, increased time spent loading the midfoot, and deceased time spent loading the forefoot in children with OI. Plantar flexion strength and the time spent at the midfoot and forefoot were most associated with ankle power generation. Conclusion The presence of pes valgus alone does not indicate a reduction of push-off power in children with type 1 OI, but those individuals who have both a flat foot and reduced time spent loading the forefoot during pushoff are the most likely to have reduced push-off power.

Journal of Experimental & Clinical Medicine, 2011

Background Many children with spastic diplegic cerebral palsy (CP) use anterior or posterior walk... more Background Many children with spastic diplegic cerebral palsy (CP) use anterior or posterior walkers to aid ambulation. Prolonged use may lead to upper extremity (UE) pathology later in life, including arthritis and joint contractures. Purpose This study analyzes the dynamics (kinematics and kinetics) of the shoulder (glenohumeral), elbow, and wrist joints during anterior and posterior walker use. It also examines the dynamic effects of adjusting handle height and grip rotation. Methods Ten children with CP underwent motion analysis with upper and lower extremity marker sets and six-degree-offreedom instrumented walker handles, while using both anterior and posterior walkers. One child underwent the same analysis, with added trials for wrist derotation (adjusted axial grip rotation) and wrist plus elbow derotation (adjusted handle height). A validated kinematic and kinetic model was applied to calculate UE joint angles, joint reaction forces (JRFs), and joint reaction moments (JRMs). Results Surprisingly, no statistically significant differences in UE angles, JRFs, or JRMs were observed between anterior and posterior walkers. Wrist derotation, however, decreased the flexion JRM seen at the wrist, and elbow derotation decreased the flexion JRM seen at the elbow. Conclusion Anterior and posterior walkers produce similar UE motion and peak loading values. Wrist and elbow joint derotation alters the dynamic effects experienced by the UEs. UE motion analysis during aided gait can be useful for optimizing UE loading conditions to limit pathology later in life.

2022 IEEE-EMBS International Conference on Biomedical and Health Informatics (BHI)

The Bone & Joint Journal, 2013

Van Nes rotationplasty may be used for patients with congenital proximal focal femoral deficiency... more Van Nes rotationplasty may be used for patients with congenital proximal focal femoral deficiency (PFFD). The lower limb is rotated to use the ankle and foot as a functional knee joint within a prosthesis. A small series of cases was investigated to determine the long-term outcome. At a mean of 21.5 years (11 to 45) after their rotationplasty, a total of 12 prosthetic patients completed the Short-Form (SF)-36, Faces Pain Scale-Revised, Harris hip score, Oswestry back pain score and Prosthetic Evaluation Questionnaires, as did 12 age- and gender-matched normal control participants. A physical examination and gait analysis, computerised dynamic posturography (CDP), and timed ‘Up & Go’ testing was also completed. Wilcoxon Signed rank test was used to compare each PFFD patient with a matched control participant with false discovery rate of 5%.There were no differences between the groups in overall health and well-being on the SF-36. Significant differences were seen in gait parameters i...

Abstracts of the 27th Annual Meeting of the GCMAS

Studies in health technology and informatics, 2010

This study uses experimental data acquired from adolescents with idiopathic scoliosis to assess t... more This study uses experimental data acquired from adolescents with idiopathic scoliosis to assess their postural control during quiet standing before and after posterior spinal fusion. Statistically significant differences were seen when comparing the pre- and post-surgical measures of balance calculated from data for three different test conditions.

License, which permits unrestricted use, distribution, and reproduction in any medium, provided t... more License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. There is minimal research of upper extremity joint dynamics during pediatric wheelchair mobility despite the large number of children using manual wheelchairs. Special concern arises with the pediatric population, particularly in regard to the longer duration of wheelchair use, joint integrity, participation and community integration, and transitional care into adulthood. This study seeks to provide evaluation methods for characterizing the biomechanics of wheelchair use by children with spinal cord injury (SCI). Twelve subjects with SCI underwent motion analysis while they propelled their wheelchair at a self-selected speed and propulsion pattern. Upper extremity joint kinematics, forces, and moments were computed using inverse dynamics methods with our custommodel.The glenohumeral joint displayed the largest average range ofmotion (ROM) at 47.1 ∘ in ...

Radiopaedia.org, 2020

Proximal focal femoral deficiency (PFFD) is a developmental disorder of the proximal segment of t... more Proximal focal femoral deficiency (PFFD) is a developmental disorder of the proximal segment of the femur and of acetabulum resulting in shortening of the affected limb and impairment of the function. It is a spectrum of congenital osseous anomalies characterized by a deficiency in the structure of the proximal femur. The diagnosis is often made by radiological evaluation which includes identification and description of PFFD and evaluation of associated limb anomalies by plain radiographs. Contrast arthrography or Magnetic Resonance Imaging is indicated when radiological features are questionable and to disclose the presence and location of the femoral head and any cartilagenous anlage. The disorder is more commonly unilateral and is apparent at birth. However, bilateral involvement is rarely seen. Therapy of the disorder is directed towards satisfactory ambulation and specific treatment depending on the severity of dysplasia.

2008 30th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 2008

This study presents initial results from a bi-planar model used to investigate the neurological f... more This study presents initial results from a bi-planar model used to investigate the neurological factors affecting balance deficits in children with diplegic cerebral palsy (CP). The model uses an inverted pendulum to describe sway in both the anteroposterior (AP) and mediolateral (ML) planes. The study presents Center of Pressure (COP) data from 17 children diagnosed with spastic diplegic CP using two standard AMTI force plates. Sway metrics in the time and frequency domains in the AP and ML planes were calculated and compared to simulations produced by the model. The proposed bi-planar model successfully reproduced sway signals acquired from experimental (clinical) data.

homepages.cae.wisc.edu

The incidence of allergy and asthma is an ever-increasing health problem in our world today. A gr... more The incidence of allergy and asthma is an ever-increasing health problem in our world today. A great deal of research is currently being directed toward determining the cause of these diseases. Lung tissue research at the cellular level deals with three individual cells; the ...

Journal of Bone and Joint Surgery-british Volume, 2013

Van Nes rotationplasty is a treatment option for individuals with congenital proximal focal femor... more Van Nes rotationplasty is a treatment option for individuals with congenital proximal focal femoral deficiency (PFFD), in which the extremity is surgically rotated to utilize the ankle and foot as a functional knee joint in a prosthesis. This case control study was done to determine the long-term function and quality of life (QOL) outcomes of these individuals. Twelve prosthetic participants (PFFD Group) and 12 control participants (Control Group) completed SF-36, Faces Pain Scale-Revised, Harris Hip Score, Oswestry back pain score and Prosthetic Evaluation Questionnaire© .Lower extremity physical exam, gait analysis, computerized dynamic posturography (CDP), and Timed 'Up & Go' testing was also completed. Wilcoxon Signed rank test used to compare each PFFD participant to the matched Control participant with false discovery rate of 5%. There were no differences between the Groups in overall health and well-being on the SF-36. Significant differences were seen in gait parameters in the PFFD Group. Using CDP, the PFFD Group showed decreased symmetry in stance, and reduced end point and maximum excursions. Individuals who underwent Van Nes rotationplasty showed a high level of function and QOL at long-term follow up, but presented with significant differences in gait and posturography parameters compared to the Control Group.

Journal of Clinical Orthopaedics and Trauma, 2021

Lateral column lengthening (LCL) is commonly performed on children and adolescents with cerebral ... more Lateral column lengthening (LCL) is commonly performed on children and adolescents with cerebral palsy (CP) for correction of pes planovalgus (PPV). There are limited reports of the long-term outcomes of this procedure. The purpose of this study was to examine the long-term results of LCL for correction of PPV in individuals with CP by evaluating subjects when they had transitioned to adulthood and were entering the workforce. Clinical assessments, quantitative gait analysis including the Milwaukee Foot Model (MFM) for segmental foot kinematics, and patient reported outcomes were collected from 13 participants with CP treated with LCL for PPV in childhood (average age 24.4 ± 5.7 years, average 15.3 ± 8.5 years since LCL). Additionally, 27 healthy adults average age 24.5 ± 3.6 years functioned as controls. Strength and joint range of motion were reduced in the PPV group (p < 0.05). Sixty nine percent showed operative correction of PPV based on radiologic criteria. Gait analysis showed reduced walking speed and stride length, as well as midfoot break and residual forefoot abduction. Patient reported outcomes indicated that foot pain was not the only factor that caused limited activity and participation. LCL surgery for PPV in childhood resulted in long-term operative correction. Decreased ankle passive range of motion and strength, subtalar joint arthritic changes, inefficient and less stable ambulation, and problems with participation (difficulties in physical function, education, and employment) were observed in the long-term. This study identified postoperative impairments and limitations to guide future clinical decision-making. These results provide clinicians and researchers the common residual and recurrent issues for these individuals as they age. The inclusion of contextual factors that influence the disease and impairments can equip these individuals with enhanced skills they need as they transition into adulthood.

Spine Deformity, 2018

This paper is NOT THE PUBLISHED VERSION; but the author's final, peer-reviewed manuscript. The pu... more This paper is NOT THE PUBLISHED VERSION; but the author's final, peer-reviewed manuscript. The published version may be accessed by following the link in th citation below.

2014 36th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 2014

While much work is being done evaluating the upper extremity joint dynamics of adult manual wheel... more While much work is being done evaluating the upper extremity joint dynamics of adult manual wheelchair propulsion, limited work has examined the pediatric population of manual wheelchair users. Our group used a custom pediatric biomechanical model to characterize the upper extremity joint dynamics of 12 children and adolescents with spinal cord injury (SCI) during wheelchair propulsion. Results show that loading appears to agree with that of adult manual wheelchair users, with the highest loading primarily seen at the glenohumeral joint. This is concerning due to the increased time of wheelchair use in the pediatric population and the impact of this loading during developmental years. This research may assist clinicians with improved mobility assessment methods, wheelchair prescription, training, and longterm care of children with orthopaedic disabilities.

2012 Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 2012

Current methods for evaluating upper extremity (UE) dynamics during pediatric wheelchair use are ... more Current methods for evaluating upper extremity (UE) dynamics during pediatric wheelchair use are limited. We propose a new model to characterize UE joint kinematics and kinetics during pediatric wheelchair mobility. The bilateral model is comprised of the thorax, clavicle, scapula, upper arm, forearm, and hand segments. The modeled joints include: sternoclavicular, acromioclavicular, glenohumeral, elbow and wrist. The model is complete and is currently undergoing pilot studies for NOT THE PUBLISHED VERSION; this is the author's final, peer-reviewed manuscript.

Critical Reviews™ in Physical and Rehabilitation Medicine, 2011

2009 Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 2009

This study examines the postural stability of children with idiopathic scoliosis, using experimen... more This study examines the postural stability of children with idiopathic scoliosis, using experimental data and a model of sway that includes mediolateral (ML) and anterioposterial (AP) components. The experimental data includes center of pressure (COP) measurements calculated from data acquired using two Advanced Medical Technology, Inc. (AMTI) force plates. Sway metrics are computed and compared with the model simulation, which successfully reproduced the clinical data from 16 children with scoliosis and 20 typically-developing children. This study is part of the first phase of a multi-year study designed to systematically assess whether fusing the spine to L4 in children with scoliosis has a significant impact on physical function and quality of life.

2011 Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 2011

Current methods for the evaluation of upper extremity dynamics during wheelchair mobility in chil... more Current methods for the evaluation of upper extremity dynamics during wheelchair mobility in children are limited. The goal of this study was to characterize upper extremity joint kinematics during wheelchair mobility. A 3-D biomechanical model of the upper extremities is presented for kinematic assessment of manual wheelchair propulsion in children with Spinal Cord Injury (SCI). The bilateral upper extremity model consists of the thorax, upper arms, forearms, and hands. The model was applied to thirteen (13) children with SCI. Joint angles and joint ranges of motion of the shoulders, elbows, and wrists were quantified. Peak joint motions during the stroke cycle were compared between right and left sides for further insight to mobility patterns. This work will provide insight to be used in future kinetic studies of wheelchair mobility.

Journal of Experimental & Clinical Medicine, 2011

Background/Purpose Children with type 1 osteogenesis imperfecta (OI) present with abnormal gait c... more Background/Purpose Children with type 1 osteogenesis imperfecta (OI) present with abnormal gait characteristics, including reduced power generation during pushoff. However, the exact biomechanical factors associated with reduced power generation are not clearly understood. The purpose of this study was to investigate the biomechanical factors associated with a reduction in ankle power generation in children with type 1 OI. Methods Twenty-four participants with type 1 OI (12.5 ± 3.6 years of age) and 24 typically developing children (12.4 ± 3.7 years of age) were evaluated. Three-dimensional gait analysis, isometric plantar flexion strength using dynamometry, and pedobarography were collected on each participant. Results were statistically compared between the groups and a correlation matrix analyzed the associations among the measures. Results Children with OI presented with weaker plantar flexors, reduced ankle power generation, and decreased sagittal plane ankle angular velocity during pushoff. However, they presented with similar moment arm distances and ground reaction force magnitudes as typically seen in developing children. There was a higher incidence of pes valgus, increased subarch angles, increased time spent loading the midfoot, and deceased time spent loading the forefoot in children with OI. Plantar flexion strength and the time spent at the midfoot and forefoot were most associated with ankle power generation. Conclusion The presence of pes valgus alone does not indicate a reduction of push-off power in children with type 1 OI, but those individuals who have both a flat foot and reduced time spent loading the forefoot during pushoff are the most likely to have reduced push-off power.

Journal of Experimental & Clinical Medicine, 2011

Background Many children with spastic diplegic cerebral palsy (CP) use anterior or posterior walk... more Background Many children with spastic diplegic cerebral palsy (CP) use anterior or posterior walkers to aid ambulation. Prolonged use may lead to upper extremity (UE) pathology later in life, including arthritis and joint contractures. Purpose This study analyzes the dynamics (kinematics and kinetics) of the shoulder (glenohumeral), elbow, and wrist joints during anterior and posterior walker use. It also examines the dynamic effects of adjusting handle height and grip rotation. Methods Ten children with CP underwent motion analysis with upper and lower extremity marker sets and six-degree-offreedom instrumented walker handles, while using both anterior and posterior walkers. One child underwent the same analysis, with added trials for wrist derotation (adjusted axial grip rotation) and wrist plus elbow derotation (adjusted handle height). A validated kinematic and kinetic model was applied to calculate UE joint angles, joint reaction forces (JRFs), and joint reaction moments (JRMs). Results Surprisingly, no statistically significant differences in UE angles, JRFs, or JRMs were observed between anterior and posterior walkers. Wrist derotation, however, decreased the flexion JRM seen at the wrist, and elbow derotation decreased the flexion JRM seen at the elbow. Conclusion Anterior and posterior walkers produce similar UE motion and peak loading values. Wrist and elbow joint derotation alters the dynamic effects experienced by the UEs. UE motion analysis during aided gait can be useful for optimizing UE loading conditions to limit pathology later in life.