IntroductionRigid 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<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.Trial RegistrationDutch Trial Register NTR3418

Chemotherapy-only treatment has increasingly become the standard of treatment for childhood acute lymphoblastic leukemia (ALL). The objective of this review is to assess the present state of knowledge of the neurocognitive effects of central nervous system (CNS)-directed chemotherapy in children with ALL, and to formulate directions for future research. We performed a review of studies published since 1997, that included an ALL group treated with chemotherapy only and a control group. Twenty-one studies met our inclusion criteria. There is evidence of subtle long-term neurocognitive deficits survivors of childhood ALL after treatment with chemotherapy only. These involve mainly processes of attention and of executive functioning, while global intellectual function is relatively preserved. Young age at diagnosis and female sex emerged as risk factors.

CNS-directed chemotherapy, even in the absence of cranial irradiation, is associated with attentional dysfunction in survivors of childhood ALL, particularly in case of intensified treatment protocols. These sequelae stress the importance of reducing doses of neurotoxic chemotherapy as much as possible in the design of future treatment protocols for ALL.

Functional gait training is a safe, feasible, and effective intervention to improve walking ability. Functional gait training shows larger positive effects on walking speed than standard physical therapy. Walking endurance and gait-related gross motor function can also benefit from functional gait training. Addition of virtual reality and biofeedback shows promise to increase engagement and improve outcomes.

BACKGROUNDThe improved prognosis of childhood cancer makes monitoring of functional outcome important. The purpose of this study was to evaluate behavioral and educational functioning in survivors of childhood acute lymphoblastic leukemia (ALL) or a Wilms tumor. In this study, children with ALL received central nervous system directed chemotherapy without cranial irradiation.METHODSIn a multicenter study, behavioral functioning and school performance was examined in 199 children age 4 to 18. Sixty‐four children were at least 1 year from finishing treatment with chemotherapy for ALL (n = 28) or a Wilms tumor (n = 36). They were compared with siblings (n = 37) and with a control group of healthy schoolchildren (n = 98).RESULTSA moderately increased risk of behavioral and educational problems was found in children with ALL but not in children with Wilms tumor. School performance was poorer in children with ALL attending primary school compared with same‐age peers; however, the rate of utilization of special education services was low. Teacher‐rated behavior and mathematics performance was correlated with attention function in children with ALL. An excess of problem behavior and underperformance at school was found in the ALL high‐risk group compared with the standard‐risk group. No differences were found between siblings and controls.CONCLUSIONEvidence is provided of subtle but significant behavioral and educational problems in survivors of childhood ALL, but no dysfunctions in survivors of a Wilms tumor. Careful follow‐up of children with ALL treated with chemotherapy only is warranted. Cancer 2006. © 2006 American Cancer Society.

Background and purpose To support clinical decision‐making in central neurological disorders, a physical examination is used to assess responses to passive muscle stretch. However, what exactly is being assessed is expressed and interpreted in different ways. A clear diagnostic framework is lacking. Therefore, the aim was to arrive at unambiguous terminology about the concepts and measurement around pathophysiological neuromuscular response to passive muscle stretch. Methods During two consensus meetings, 37 experts from 12 European countries filled online questionnaires based on a Delphi approach, followed by plenary discussion after rounds. Consensus was reached for agreement ≥75%. Results The term hyper‐resistance should be used to describe the phenomenon of impaired neuromuscular response during passive stretch, instead of for example ‘spasticity’ or ‘hypertonia’. From there, it is essential to distinguish non‐neural (tissue‐related) from neural (central nervous system related) contributions to hyper‐resistance. Tissue contributions are elasticity, viscosity and muscle shortening. Neural contributions are velocity dependent stretch hyperreflexia and non‐velocity dependent involuntary background activation. The term ‘spasticity’ should only be used next to stretch hyperreflexia, and ‘stiffness’ next to passive tissue contributions. When joint angle, moment and electromyography are recorded, components of hyper‐resistance within the framework can be quantitatively assessed. Conclusions A conceptual framework of pathophysiological responses to passive muscle stretch is defined. This framework can be used in clinical assessment of hyper‐resistance and will improve communication between clinicians. Components within the framework are defined by objective parameters from instrumented assessment. These parameters need experimental validation in order to develop treatment algorithms based on the aetiology of the clinical phenomena.

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.

Treatment for childhood acute lymphoblastic leukemia (ALL), which includes CNS prophylaxis, is associated with central and peripheral neurotoxicity. The purpose of the present study was to analyze the effects of chemotherapy on various levels of visuomotor control in survivors of childhood ALL treated without cranial irradiation, and to identify risk factors for possible deficits. Visuomotor function was compared between children after treatment for ALL (n 5 34), children after treatment for Wilms tumor, which consists of non-CNS directed chemotherapy (n 5 38), and healthy controls (n 5 151). Three tasks were administered: a simple visual reaction time task and two tasks measuring visuomotor control with one requiring a higher level of cognitive control than the other. Visuomotor deficits were detected only in the ALL group, with poorer performance restricted to the condition requiring the highest level of control. Significant risk factors for poorer performance were female gender and a short time since end of treatment, and a trend was found for a young age at diagnosis. A high cumulative methotrexate dose was an adverse predictive factor in girls. The results indicate that chemotherapy-induced central neurotoxicity in childhood ALL treatment is associated with higher order visuomotor control deficits. Girls appear to be particularly vulnerable. (JINS, 2005, 11, 554-565.)