Objective: To compare daily stride rate activity, daily exercise intensity, and heart rate intens... more Objective: To compare daily stride rate activity, daily exercise intensity, and heart rate intensity of stride rate in children with cerebral palsy with that of typically developing children. Methods: Forty-three children with cerebral palsy, walking without (Gross Motor Function Classification System (GMFCS) I and II) or with (GMFCS III) an aid and 27 typically developing children (age range 7-14 years) wore a StepWatch TM activity monitor and a heart rate monitor. Time spent and mean heart rate reserve at each stride rate activity level and time spent in each mean heart rate reserve zone was compared. Results: Daily stride rate activity was lower in children with cerebral palsy (39%, 49% and 79% in GMFCS I, II and III, respectively) compared with typically developing children (p < 0.05), while there were no differences in time spent at different mean heart rate reserve zones. Mean heart rate reserve at all stride rate activity levels was not different between typically developing children, GMFCS I and II, while mean heart rate reserve was higher for GFMCS III at stride rates < 30 strides/min (p < 0.05). Conclusion: Stride rate activity levels reflect the effort of walking, in children with cerebral palsy who are walking without aids, similar to that of typically developing children, whereas children with cerebral palsy using walking aids show higher effort of walking. Despite a lower stride rate activity in cerebral palsy, daily exercise intensity seems comparable, indicating that the StepWatch TM monitor and the heart rate monitor measure different aspects of physical activity.
In several neurological disorders and muscle injuries, morphological changes of the m. semitendin... more In several neurological disorders and muscle injuries, morphological changes of the m. semitendinosus (ST) are presumed to contribute to movement limitations around the knee. Freehand three-dimensional (3D) ultrasound (US), using position tracking of two-dimensional US images to reconstruct a 3D voxel array, can be used to assess muscle morphology in vivo. The aims of this study were: (i) to introduce a newly developed 3D US protocol for ST; and (ii) provide a first comparison of morphological characteristics determined by 3D US with those measured on dissected cadaveric muscles. Morphological characteristics of ST (e.g. muscle belly length, tendon length, fascicle length and whole muscle volume, and volumes of both compartments) were assessed in six cadavers using a 3D US protocol. Subsequently, ST muscles were removed from the body to measure the same morphological characteristics. Mean differences between morphological characteristics measured by 3D US and after dissection were smaller than 10%. Intra-class correlation coefficients (ICCs) were higher than 0.75 for all variables except for the lengths of proximal fascicles (ICC = 0.58). Measurement of the volume of proximal compartment by 3D US was not feasible, due to low US image quality proximally. We conclude that the presented 3D US protocol allows for reasonably accurate measurements of key morphological characteristics of ST muscle.
Archives of Physical Medicine and Rehabilitation, 2016
To examine associations over longitudinal measurements between neuromusculoskeletal function and ... more To examine associations over longitudinal measurements between neuromusculoskeletal function and gross motor capacity in children and youth with cerebral palsy (CP). A prospective cohort study. Rehabilitation departments of university medical centers and rehabilitations centers. A sample (N=327) consisting of 148 children (aged 5-9y) and 179 youth (aged 11-20y) with CP, Gross Motor Function Classification System level I (n=180), level II (n=44), level III (n=36), level IV (n=34), and level V (n=33). Not applicable. Gross motor capacity was assessed with the Gross Motor Function Measure-66 over a period of 2 to 4 years in different age cohorts. Neuromusculoskeletal function included selective motor control (SMC), muscle strength, spasticity, and range of motion (ROM) of the lower extremities. Multilevel analyses showed that SMC was significantly associated with gross motor capacity in children and youth with CP, showing higher values and a more favorable course of gross motor capacity in those with better SMC. Strength was only associated with gross motor capacity in youth. Reduced ROM of hip (children) and knee extension (youth) and spasticity of the hip adductors (youth) were additionally-but more weakly-associated with lower values and a less favorable course of gross motor capacity. Results indicate that children and youth with more severely impaired SMC and youth with reduced muscle strength have a less favorable course of gross motor capacity, while spasticity and reduced ROM are less determinative.
Cerebral palsy is the most common cause of childhood-onset, lifelong physical disability in most ... more Cerebral palsy is the most common cause of childhood-onset, lifelong physical disability in most countries, affecting about 1 in 500 neonates with an estimated prevalence of 17 million people worldwide. Cerebral palsy is not a disease entity in the traditional sense but a clinical description of children who share features of a non-progressive brain injury or lesion acquired during the antenatal, perinatal or early postnatal period. The clinical manifestations of cerebral palsy vary greatly in the type of movement disorder, the degree of functional ability and limitation and the affected parts of the body. There is currently no cure, but progress is being made in both the prevention and the amelioration of the brain injury. For example, administration of magnesium sulfate during premature labour and cooling of high-risk infants can reduce the rate and severity of cerebral palsy. Although the disorder affects individuals throughout their lifetime, most cerebral palsy research efforts...
Selective dorsal rhizotomy (SDR) surgery is a well-established treatment for ambulatory children ... more Selective dorsal rhizotomy (SDR) surgery is a well-established treatment for ambulatory children with bilateral spastic paresis and is performed to eliminate spasticity and improve walking. The objective of this case report is to describe sudden falls as a persistent complication of SDR. The authors report on 3 patients with bilateral spastic paresis, aged 12, 6, and 7 years at the time of surgery. The percentage of transected dorsal rootlets was around 40% at the L2-S1 levels. Sudden falls were reported with a frequency of several a day, continuing for years after SDR. The falls were often triggered by performing dual tasks as well as occurring in the transition from sitting to standing, during running, after strenuous exercise, or following a fright. Patients also had residual hyperesthesia and dysesthesia of the foot sole. The authors hypothesize that the sudden falls are caused by a muscle inhibition reflex of the muscles in the legs, as an abnormal reaction to a sensory stimulu...
Dynamometry has been used extensively to measure knee extensor strength in individuals with cereb... more Dynamometry has been used extensively to measure knee extensor strength in individuals with cerebral palsy (CP). However, increased coactivation can lead to underestimation of knee extensor strength and, therefore, reduce validity of strength measurements. It is yet unknown to what extent coactivation occurs during dynamometry testing and whether coactivation is influenced by severity of CP, load levels, and muscle fatigue. The aims of this study were: (1) to investigate coactivation in adolescents with and without CP during dynamometer tests and (2) to assess the effect of Gross Motor Function Classification System (GMFCS) level, load level, and muscle fatigue on coactivation. A cross-sectional observational design was used. Sixteen adolescents with CP (GMFCS levels I and II: n=10/6; age range=13-19 years) and 15 adolescents without CP (n=15; age range=12-19 years) performed maximal isometric contractions (maximal voluntary torque [MVT]) and a series of submaximal dynamic contracti...
Intrathecal baclofen (ITB) treatment is applied in patients with spastic cerebral palsy (SCP), dy... more Intrathecal baclofen (ITB) treatment is applied in patients with spastic cerebral palsy (SCP), dystonic cerebral palsy (DCP) and progressive neurological disease (PND). Our aim was to investigate whether ITB treatment has a different effect on activities of daily life (ADL) in these groups. A retrospective and cross-sectional survey was conducted using a questionnaire to assess the qualitative effect of ITB (Likert scale) on different domains of functioning (mobility, personal care, communication, comfort) and satisfaction with the results. Groups were compared using non-parametric statistics. Questionnaires were completed for 68 patients (39 SCP, 13 DCP, 16 PND). Satisfaction scores were relatively high in all groups (7-8) and the positive effect on personal care and communication was similar in all groups. The PND group had the shortest follow-up and scored significantly less favourably for the effect on mobility and comfort. This is the first study to show that ITB treatment has similar effects on personal care and communication in stable and progressive neurological disease. The decrease in mobility in the PND group is likely due to the progressive nature of the disease. The different effect on comfort between groups is mainly due to the smaller effect on startles in the PND group.
To determine the relationship between isometric leg muscle strength and mobility capacity in chil... more To determine the relationship between isometric leg muscle strength and mobility capacity in children with cerebral palsy (CP) compared to typically developing (TD) peers. Participants were 62 children with CP (6-13 years), able to walk with (n = 10) or without (n = 52) walking aids, and 47 TD children. Isometric muscle strength of five muscle groups of the leg was measured using hand-held dynamometry. Mobility capacity was assessed with the 1-min walk, the 10-m walk, sit-to-stand, lateral-step-up and timed-stair tests. Isometric strength of children with CP was reduced to 36-82% of TD. When adjusted for age and height, the percentage of variance in mobility capacity that was explained by isometric strength of the leg muscles was 21-24% (walking speed), 25% (sit-to-stand), 28% (lateral-step-up) and 35% (timed-stair) in children with CP. Hip abductors and knee flexors had the largest contribution to the explained variance, while knee extensors showed the weakest correlation. Weak or ...
Rigid Ankle-Foot Orthoses (AFOs) are commonly prescribed to counteract excessive knee flexion dur... more Rigid Ankle-Foot Orthoses (AFOs) are commonly prescribed to counteract excessive knee flexion during the stance phase of gait in children with cerebral palsy (CP). While rigid AFOs may normalize knee kinematics and kinetics effectively, it has the disadvantage of impeding push-off power. A spring-like AFO may enhance push-off power, which may come at the cost of reducing the knee flexion less effectively. Optimizing this trade-off between enhancing push-off power and normalizing knee flexion in stance is expected to maximize gait efficiency. This study investigated the effects of varying AFO stiffness on gait biomechanics and efficiency in children with CP who walk with excessive knee flexion in stance. Fifteen children with spastic CP (11 boys, 10±2 years) were prescribed with a ventral shell spring-hinged AFO (vAFO). The hinge was set into a rigid, or spring-like setting, using both a stiff and flexible performance. At baseline (i.e. shoes-only) and for each vAFO, a 3D-gait analysis and 6-minute walk test with breath-gas analysis were performed at comfortable speed. Lower limb joint kinematics and kinetics were calculated. From the 6-minute walk test, walking speed and the net energy cost were determined. A generalized estimation equation (p&amp;amp;amp;amp;amp;amp;lt;0.05) was used to analyze the effects of different conditions. Compared to shoes-only, all vAFOs improved the knee angle and net moment similarly. Ankle power generation and work were preserved only by the spring-like vAFOs. All vAFOs decreased the net energy cost compared to shoes-only, but no differences were found between vAFOs, showing that the effects of spring-like vAFOs to promote push-off power did not lead to greater reductions in walking energy cost. These findings suggest that, in this specific group of children with spastic CP, the vAFO stiffness that maximizes gait efficiency is primarily determined by its effect on knee kinematics and kinetics rather than by its effect on push-off power. Dutch Trial Register NTR3418.
OBJECTIVE: To develop a Rasch-based version of a mobility questionnaire (MobQues28) for children ... more OBJECTIVE: To develop a Rasch-based version of a mobility questionnaire (MobQues28) for children with cerebral palsy (CP). DESIGN: Cross-sectional study. SETTING: Private physical therapy practices and outpatient departments of hospitals and rehabilitation centers. PARTICIPANTS: Parents of 323 ambulatory children with CP (Gross Motor Function Classification System [GMFCS] level I-IV; aged, 2-13y). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: The mobility questionnaire measures mobility limitations in children with CP by rating the difficulty of executing 47 mobility activities, as reported by the parents. Items for the Rasch-based version were selected based on fit to the Rasch measurement (partial credit) model and invariance of item characteristics across GMFCS level, age group, or sex. RESULTS: Analysis revealed a fitting model when nonambulant and/or 2-and 3-year aged children were excluded (leaving a final sample of n=246) and answering categories were collapsed from 9 to 5. Thirteen items were removed from the questionnaire due to misfit to the model, 5 because of disordered thresholds, and 1 because of invariance across age group. Twentyeight items out of the original 47 items showed good fit to the model. CONCLUSIONS: The 28-item version of the mobility questionnaire (MobQues28) provides sound measurement properties for measuring mobility limitations in ambulant children with CP, aged 4 to 13 years, and shows promise as an instrument for research purposes.
ABSTRACT Doel van dit onderzoek is een analyse van de complicaties bij kinderen met intrathecale ... more ABSTRACT Doel van dit onderzoek is een analyse van de complicaties bij kinderen met intrathecale baclofentherapie. Meer specifiek werd gekeken naar aard, frequentie, impact (d.m.v. verzorgertevredenheid) en mogelijke determinanten van het optreden van complicaties. Hiertoe werd retrospectief statusonderzoek uitgevoerd en een cross-sectionele tevredenheidsvragenlijst afgenomen. Alle kinderen (t/m 17 jaar) behandeld met intrathecale baclofentherapie in het VU medisch centrum zijn geanalyseerd. De minimale follow-up was zes maanden. Het betreft baclofenpompimplantaties tussen maart 2001 en mei 2007. Een complicatiefrequentie van 0,28 (0,19-0,42) complicaties per patiënt per jaar werd gevonden. In de literatuur bedraagt de complicatiefrequentie tussen de 0,09 en 0,58 complicaties per patiënt per jaar. Kathetergerelateerde complicaties kwamen het meest frequent voor. Drie gevonden determinanten voor het optreden van complicaties zijn: kathetertiphoogte, pulmonale comorbiditeit en corticosteroïdengebruik. Het tevredenheidsonderzoek wees uit dat ouders/verzorgers van kinderen met één of meer complicaties niet minder tevreden waren dan ouders van kinderen zonder complicaties. Van de ondervraagden zou 88% de keuze voor intrathecale baclofentherapie nog steeds maken. De resultaten van het tevredenheidsonderzoek bevestigen de hypothese dat ouders/verzorgers in hun oordeel de functionele waarde van de behandeling zwaarder laten wegen dan de eventuele complicaties. Aim of this research is an analysis of the complications in children with intrathecal baclofen therapy. More specific by analysing nature, frequency, impact (by means of caregiver satisfaction) and possible determinants of complications. For that purpose retrospective data research was conducted and a cross-sectional satisfaction questionnaire was administered. All children treated with intrathecal baclofen therapy in the VU medical centre, Amsterdam, are included in the study. Minimum follow-up was six months. The baclofen pumps were implanted from March 2001 to May 2007.We found 0.28 (0.19-0.42) complications per patient per year. In other studies this value varies between 0.09 and 0.58 complications per patient per year. Catheter-related complications were the most common. Three determinants proved to be associated with the rate of complications: the level of the catheter tip, pulmonary co-morbidity and the use of corticosteroids. The results of the satisfaction questionnaire showed that there is no less satisfaction in parents/guardians of children with one or more complications as compared to parents of children without complications. Of parents questioned, 88% would again choose for intrathecal baclofen therapy. The results of the satisfaction questionnaire support the hypothesis that in their judgement parents/guardians focus more on functional gain of the treatment than on possible complications.
The Journal of Rehabilitation Research and Development
Based on the results of several electrodiagnostic and biomechanical studies, the following classi... more Based on the results of several electrodiagnostic and biomechanical studies, the following classification of muscle dysfunction in spastic hemiplegia is proposed: changes in muscle activation (excess symptoms, e .g ., spasticity, and deficit symptoms, e .g ., paresis) ; changes in muscle stiffness ; and changes in muscle length . The clinical significance of this classification is that different types of muscle dysfunction might require specific treatment.
In disabling orthopaedic and neurological disorders, in addition to clinical and imaging examinat... more In disabling orthopaedic and neurological disorders, in addition to clinical and imaging examination, observation of the motion is an important method of examination. It serves as a starting point for the motion analysis using digital video. In this way, muscle functions can be measured with the aid of a kinesiological EMG. Load on the joints of the lower extremities can be deduced from a projection of the foot reaction vector on the body. Combination of a video film of the motion (the gait) with measurement of the kinesiological EMG provides a motion analysis based on multimedia techniques. With modern personal computers, interactive examination of these digital data is simple. Three examples of this functionality can be viewed at the Internet site of this journal (http:@appendix.niwi.knaw.nl): the normal walking cycle, the active stabilization of the knee after an injury of the anterior cruciate ligament and the gait of a woman with cerebral palsy before and after orthopaedic surgery. Motion analysis using multimedia techniques makes it possible to analyse relationships between muscular and articular functions on the one hand and impaired motion on the other in a way that is meaningful to the clinician.
Objective: To compare daily stride rate activity, daily exercise intensity, and heart rate intens... more Objective: To compare daily stride rate activity, daily exercise intensity, and heart rate intensity of stride rate in children with cerebral palsy with that of typically developing children. Methods: Forty-three children with cerebral palsy, walking without (Gross Motor Function Classification System (GMFCS) I and II) or with (GMFCS III) an aid and 27 typically developing children (age range 7-14 years) wore a StepWatch TM activity monitor and a heart rate monitor. Time spent and mean heart rate reserve at each stride rate activity level and time spent in each mean heart rate reserve zone was compared. Results: Daily stride rate activity was lower in children with cerebral palsy (39%, 49% and 79% in GMFCS I, II and III, respectively) compared with typically developing children (p < 0.05), while there were no differences in time spent at different mean heart rate reserve zones. Mean heart rate reserve at all stride rate activity levels was not different between typically developing children, GMFCS I and II, while mean heart rate reserve was higher for GFMCS III at stride rates < 30 strides/min (p < 0.05). Conclusion: Stride rate activity levels reflect the effort of walking, in children with cerebral palsy who are walking without aids, similar to that of typically developing children, whereas children with cerebral palsy using walking aids show higher effort of walking. Despite a lower stride rate activity in cerebral palsy, daily exercise intensity seems comparable, indicating that the StepWatch TM monitor and the heart rate monitor measure different aspects of physical activity.
In several neurological disorders and muscle injuries, morphological changes of the m. semitendin... more In several neurological disorders and muscle injuries, morphological changes of the m. semitendinosus (ST) are presumed to contribute to movement limitations around the knee. Freehand three-dimensional (3D) ultrasound (US), using position tracking of two-dimensional US images to reconstruct a 3D voxel array, can be used to assess muscle morphology in vivo. The aims of this study were: (i) to introduce a newly developed 3D US protocol for ST; and (ii) provide a first comparison of morphological characteristics determined by 3D US with those measured on dissected cadaveric muscles. Morphological characteristics of ST (e.g. muscle belly length, tendon length, fascicle length and whole muscle volume, and volumes of both compartments) were assessed in six cadavers using a 3D US protocol. Subsequently, ST muscles were removed from the body to measure the same morphological characteristics. Mean differences between morphological characteristics measured by 3D US and after dissection were smaller than 10%. Intra-class correlation coefficients (ICCs) were higher than 0.75 for all variables except for the lengths of proximal fascicles (ICC = 0.58). Measurement of the volume of proximal compartment by 3D US was not feasible, due to low US image quality proximally. We conclude that the presented 3D US protocol allows for reasonably accurate measurements of key morphological characteristics of ST muscle.
Archives of Physical Medicine and Rehabilitation, 2016
To examine associations over longitudinal measurements between neuromusculoskeletal function and ... more To examine associations over longitudinal measurements between neuromusculoskeletal function and gross motor capacity in children and youth with cerebral palsy (CP). A prospective cohort study. Rehabilitation departments of university medical centers and rehabilitations centers. A sample (N=327) consisting of 148 children (aged 5-9y) and 179 youth (aged 11-20y) with CP, Gross Motor Function Classification System level I (n=180), level II (n=44), level III (n=36), level IV (n=34), and level V (n=33). Not applicable. Gross motor capacity was assessed with the Gross Motor Function Measure-66 over a period of 2 to 4 years in different age cohorts. Neuromusculoskeletal function included selective motor control (SMC), muscle strength, spasticity, and range of motion (ROM) of the lower extremities. Multilevel analyses showed that SMC was significantly associated with gross motor capacity in children and youth with CP, showing higher values and a more favorable course of gross motor capacity in those with better SMC. Strength was only associated with gross motor capacity in youth. Reduced ROM of hip (children) and knee extension (youth) and spasticity of the hip adductors (youth) were additionally-but more weakly-associated with lower values and a less favorable course of gross motor capacity. Results indicate that children and youth with more severely impaired SMC and youth with reduced muscle strength have a less favorable course of gross motor capacity, while spasticity and reduced ROM are less determinative.
Cerebral palsy is the most common cause of childhood-onset, lifelong physical disability in most ... more Cerebral palsy is the most common cause of childhood-onset, lifelong physical disability in most countries, affecting about 1 in 500 neonates with an estimated prevalence of 17 million people worldwide. Cerebral palsy is not a disease entity in the traditional sense but a clinical description of children who share features of a non-progressive brain injury or lesion acquired during the antenatal, perinatal or early postnatal period. The clinical manifestations of cerebral palsy vary greatly in the type of movement disorder, the degree of functional ability and limitation and the affected parts of the body. There is currently no cure, but progress is being made in both the prevention and the amelioration of the brain injury. For example, administration of magnesium sulfate during premature labour and cooling of high-risk infants can reduce the rate and severity of cerebral palsy. Although the disorder affects individuals throughout their lifetime, most cerebral palsy research efforts...
Selective dorsal rhizotomy (SDR) surgery is a well-established treatment for ambulatory children ... more Selective dorsal rhizotomy (SDR) surgery is a well-established treatment for ambulatory children with bilateral spastic paresis and is performed to eliminate spasticity and improve walking. The objective of this case report is to describe sudden falls as a persistent complication of SDR. The authors report on 3 patients with bilateral spastic paresis, aged 12, 6, and 7 years at the time of surgery. The percentage of transected dorsal rootlets was around 40% at the L2-S1 levels. Sudden falls were reported with a frequency of several a day, continuing for years after SDR. The falls were often triggered by performing dual tasks as well as occurring in the transition from sitting to standing, during running, after strenuous exercise, or following a fright. Patients also had residual hyperesthesia and dysesthesia of the foot sole. The authors hypothesize that the sudden falls are caused by a muscle inhibition reflex of the muscles in the legs, as an abnormal reaction to a sensory stimulu...
Dynamometry has been used extensively to measure knee extensor strength in individuals with cereb... more Dynamometry has been used extensively to measure knee extensor strength in individuals with cerebral palsy (CP). However, increased coactivation can lead to underestimation of knee extensor strength and, therefore, reduce validity of strength measurements. It is yet unknown to what extent coactivation occurs during dynamometry testing and whether coactivation is influenced by severity of CP, load levels, and muscle fatigue. The aims of this study were: (1) to investigate coactivation in adolescents with and without CP during dynamometer tests and (2) to assess the effect of Gross Motor Function Classification System (GMFCS) level, load level, and muscle fatigue on coactivation. A cross-sectional observational design was used. Sixteen adolescents with CP (GMFCS levels I and II: n=10/6; age range=13-19 years) and 15 adolescents without CP (n=15; age range=12-19 years) performed maximal isometric contractions (maximal voluntary torque [MVT]) and a series of submaximal dynamic contracti...
Intrathecal baclofen (ITB) treatment is applied in patients with spastic cerebral palsy (SCP), dy... more Intrathecal baclofen (ITB) treatment is applied in patients with spastic cerebral palsy (SCP), dystonic cerebral palsy (DCP) and progressive neurological disease (PND). Our aim was to investigate whether ITB treatment has a different effect on activities of daily life (ADL) in these groups. A retrospective and cross-sectional survey was conducted using a questionnaire to assess the qualitative effect of ITB (Likert scale) on different domains of functioning (mobility, personal care, communication, comfort) and satisfaction with the results. Groups were compared using non-parametric statistics. Questionnaires were completed for 68 patients (39 SCP, 13 DCP, 16 PND). Satisfaction scores were relatively high in all groups (7-8) and the positive effect on personal care and communication was similar in all groups. The PND group had the shortest follow-up and scored significantly less favourably for the effect on mobility and comfort. This is the first study to show that ITB treatment has similar effects on personal care and communication in stable and progressive neurological disease. The decrease in mobility in the PND group is likely due to the progressive nature of the disease. The different effect on comfort between groups is mainly due to the smaller effect on startles in the PND group.
To determine the relationship between isometric leg muscle strength and mobility capacity in chil... more To determine the relationship between isometric leg muscle strength and mobility capacity in children with cerebral palsy (CP) compared to typically developing (TD) peers. Participants were 62 children with CP (6-13 years), able to walk with (n = 10) or without (n = 52) walking aids, and 47 TD children. Isometric muscle strength of five muscle groups of the leg was measured using hand-held dynamometry. Mobility capacity was assessed with the 1-min walk, the 10-m walk, sit-to-stand, lateral-step-up and timed-stair tests. Isometric strength of children with CP was reduced to 36-82% of TD. When adjusted for age and height, the percentage of variance in mobility capacity that was explained by isometric strength of the leg muscles was 21-24% (walking speed), 25% (sit-to-stand), 28% (lateral-step-up) and 35% (timed-stair) in children with CP. Hip abductors and knee flexors had the largest contribution to the explained variance, while knee extensors showed the weakest correlation. Weak or ...
Rigid Ankle-Foot Orthoses (AFOs) are commonly prescribed to counteract excessive knee flexion dur... more Rigid Ankle-Foot Orthoses (AFOs) are commonly prescribed to counteract excessive knee flexion during the stance phase of gait in children with cerebral palsy (CP). While rigid AFOs may normalize knee kinematics and kinetics effectively, it has the disadvantage of impeding push-off power. A spring-like AFO may enhance push-off power, which may come at the cost of reducing the knee flexion less effectively. Optimizing this trade-off between enhancing push-off power and normalizing knee flexion in stance is expected to maximize gait efficiency. This study investigated the effects of varying AFO stiffness on gait biomechanics and efficiency in children with CP who walk with excessive knee flexion in stance. Fifteen children with spastic CP (11 boys, 10±2 years) were prescribed with a ventral shell spring-hinged AFO (vAFO). The hinge was set into a rigid, or spring-like setting, using both a stiff and flexible performance. At baseline (i.e. shoes-only) and for each vAFO, a 3D-gait analysis and 6-minute walk test with breath-gas analysis were performed at comfortable speed. Lower limb joint kinematics and kinetics were calculated. From the 6-minute walk test, walking speed and the net energy cost were determined. A generalized estimation equation (p&amp;amp;amp;amp;amp;amp;lt;0.05) was used to analyze the effects of different conditions. Compared to shoes-only, all vAFOs improved the knee angle and net moment similarly. Ankle power generation and work were preserved only by the spring-like vAFOs. All vAFOs decreased the net energy cost compared to shoes-only, but no differences were found between vAFOs, showing that the effects of spring-like vAFOs to promote push-off power did not lead to greater reductions in walking energy cost. These findings suggest that, in this specific group of children with spastic CP, the vAFO stiffness that maximizes gait efficiency is primarily determined by its effect on knee kinematics and kinetics rather than by its effect on push-off power. Dutch Trial Register NTR3418.
OBJECTIVE: To develop a Rasch-based version of a mobility questionnaire (MobQues28) for children ... more OBJECTIVE: To develop a Rasch-based version of a mobility questionnaire (MobQues28) for children with cerebral palsy (CP). DESIGN: Cross-sectional study. SETTING: Private physical therapy practices and outpatient departments of hospitals and rehabilitation centers. PARTICIPANTS: Parents of 323 ambulatory children with CP (Gross Motor Function Classification System [GMFCS] level I-IV; aged, 2-13y). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: The mobility questionnaire measures mobility limitations in children with CP by rating the difficulty of executing 47 mobility activities, as reported by the parents. Items for the Rasch-based version were selected based on fit to the Rasch measurement (partial credit) model and invariance of item characteristics across GMFCS level, age group, or sex. RESULTS: Analysis revealed a fitting model when nonambulant and/or 2-and 3-year aged children were excluded (leaving a final sample of n=246) and answering categories were collapsed from 9 to 5. Thirteen items were removed from the questionnaire due to misfit to the model, 5 because of disordered thresholds, and 1 because of invariance across age group. Twentyeight items out of the original 47 items showed good fit to the model. CONCLUSIONS: The 28-item version of the mobility questionnaire (MobQues28) provides sound measurement properties for measuring mobility limitations in ambulant children with CP, aged 4 to 13 years, and shows promise as an instrument for research purposes.
ABSTRACT Doel van dit onderzoek is een analyse van de complicaties bij kinderen met intrathecale ... more ABSTRACT Doel van dit onderzoek is een analyse van de complicaties bij kinderen met intrathecale baclofentherapie. Meer specifiek werd gekeken naar aard, frequentie, impact (d.m.v. verzorgertevredenheid) en mogelijke determinanten van het optreden van complicaties. Hiertoe werd retrospectief statusonderzoek uitgevoerd en een cross-sectionele tevredenheidsvragenlijst afgenomen. Alle kinderen (t/m 17 jaar) behandeld met intrathecale baclofentherapie in het VU medisch centrum zijn geanalyseerd. De minimale follow-up was zes maanden. Het betreft baclofenpompimplantaties tussen maart 2001 en mei 2007. Een complicatiefrequentie van 0,28 (0,19-0,42) complicaties per patiënt per jaar werd gevonden. In de literatuur bedraagt de complicatiefrequentie tussen de 0,09 en 0,58 complicaties per patiënt per jaar. Kathetergerelateerde complicaties kwamen het meest frequent voor. Drie gevonden determinanten voor het optreden van complicaties zijn: kathetertiphoogte, pulmonale comorbiditeit en corticosteroïdengebruik. Het tevredenheidsonderzoek wees uit dat ouders/verzorgers van kinderen met één of meer complicaties niet minder tevreden waren dan ouders van kinderen zonder complicaties. Van de ondervraagden zou 88% de keuze voor intrathecale baclofentherapie nog steeds maken. De resultaten van het tevredenheidsonderzoek bevestigen de hypothese dat ouders/verzorgers in hun oordeel de functionele waarde van de behandeling zwaarder laten wegen dan de eventuele complicaties. Aim of this research is an analysis of the complications in children with intrathecal baclofen therapy. More specific by analysing nature, frequency, impact (by means of caregiver satisfaction) and possible determinants of complications. For that purpose retrospective data research was conducted and a cross-sectional satisfaction questionnaire was administered. All children treated with intrathecal baclofen therapy in the VU medical centre, Amsterdam, are included in the study. Minimum follow-up was six months. The baclofen pumps were implanted from March 2001 to May 2007.We found 0.28 (0.19-0.42) complications per patient per year. In other studies this value varies between 0.09 and 0.58 complications per patient per year. Catheter-related complications were the most common. Three determinants proved to be associated with the rate of complications: the level of the catheter tip, pulmonary co-morbidity and the use of corticosteroids. The results of the satisfaction questionnaire showed that there is no less satisfaction in parents/guardians of children with one or more complications as compared to parents of children without complications. Of parents questioned, 88% would again choose for intrathecal baclofen therapy. The results of the satisfaction questionnaire support the hypothesis that in their judgement parents/guardians focus more on functional gain of the treatment than on possible complications.
The Journal of Rehabilitation Research and Development
Based on the results of several electrodiagnostic and biomechanical studies, the following classi... more Based on the results of several electrodiagnostic and biomechanical studies, the following classification of muscle dysfunction in spastic hemiplegia is proposed: changes in muscle activation (excess symptoms, e .g ., spasticity, and deficit symptoms, e .g ., paresis) ; changes in muscle stiffness ; and changes in muscle length . The clinical significance of this classification is that different types of muscle dysfunction might require specific treatment.
In disabling orthopaedic and neurological disorders, in addition to clinical and imaging examinat... more In disabling orthopaedic and neurological disorders, in addition to clinical and imaging examination, observation of the motion is an important method of examination. It serves as a starting point for the motion analysis using digital video. In this way, muscle functions can be measured with the aid of a kinesiological EMG. Load on the joints of the lower extremities can be deduced from a projection of the foot reaction vector on the body. Combination of a video film of the motion (the gait) with measurement of the kinesiological EMG provides a motion analysis based on multimedia techniques. With modern personal computers, interactive examination of these digital data is simple. Three examples of this functionality can be viewed at the Internet site of this journal (http:@appendix.niwi.knaw.nl): the normal walking cycle, the active stabilization of the knee after an injury of the anterior cruciate ligament and the gait of a woman with cerebral palsy before and after orthopaedic surgery. Motion analysis using multimedia techniques makes it possible to analyse relationships between muscular and articular functions on the one hand and impaired motion on the other in a way that is meaningful to the clinician.
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Papers by Jules Becher