Eileen Fowler

Promotion of Physical Fitness and Prevention of Secondary Conditions for Children With Cerebral Palsy: Section on Pediatrics Research Summit Proceedings

Inadequate physical fitness is a major problem affecting the function and health of children with cerebral palsy (CP). Lack of optimal physical activity may contribute to the development of secondary conditions associated with CP such as chronic pain, fatigue, and osteoporosis. The purpose of this article is to highlight the content and recommendations of a Pediatrics Research Summit developed to foster collaborative research in this area. Two components of physical fitness—muscle strength and cardiorespiratory fitness—were emphasized. Although there is evidence to support the use of physical fitness interventions, there are many gaps in our current knowledge. Additional research of higher quality and rigor is needed in order to make definitive recommendations regarding the mode, intensity, frequency, and duration of exercise. Outcome measurements have focused on the body functions and structures level of the International Classification of Functioning, Disability and Health (ICF), and much less is known about effects at the activities and participation levels. Additionally, the influence of nutritional and growth factors on physical fitness has not been studied in this population, in which poor growth and skeletal fragility have been identified as serious health issues. Current intervention protocols and outcome measurements were critically evaluated, and recommendations were made for future research.

DEFINITION AND CLASSIFICATION OF HYPERKINETIC MOVEMENTS IN CHILDHOOD

Hyperkinetic movements are unwanted or excess movements that are frequently seen in children with neurologic disorders. They are an important clinical finding with significant implications for diagnosis and treatment. However, the lack of agreement on standard terminology and definitions interferes with clinical treatment and research. We describe definitions of dystonia, chorea, athetosis, myoclonus, tremor, tics, and stereotypies that arose from a consensus meeting in June 2008 of specialists from different clinical and basic science fields. Dystonia is a movement disorder in which involuntary sustained or intermittent muscle contractions cause twisting and repetitive movements, abnormal postures, or both. Chorea is an ongoing random‐appearing sequence of one or more discrete involuntary movements or movement fragments. Athetosis is a slow, continuous, involuntary writhing movement that prevents maintenance of a stable posture. Myoclonus is a sequence of repeated, often nonrhythmic, brief shock‐like jerks due to sudden involuntary contraction or relaxation of one or more muscles. Tremor is a rhythmic back‐and‐forth or oscillating involuntary movement about a joint axis. Tics are repeated, individually recognizable, intermittent movements or movement fragments that are almost always briefly suppressible and are usually associated with awareness of an urge to perform the movement. Stereotypies are repetitive, simple movements that can be voluntarily suppressed. We provide recommended techniques for clinical examination and suggestions for differentiating between the different types of hyperkinetic movements, noting that there may be overlap between conditions. These definitions and the diagnostic recommendations are intended to be reliable and useful for clinical practice, communication between clinicians and researchers, and for the design of quantitative tests that will guide and assess the outcome of future clinical trials.

Definition and Classification of Negative Motor Signs in Childhood

In this report we describe the outcome of a consensus meeting that occurred at the National Institutes of Health in Bethesda, Maryland, March 12 through 14, 2005. The meeting brought together 39 specialists from multiple clinical and research disciplines including developmental pediatrics, neurology, neurosurgery, orthopedic surgery, physical therapy, occupational therapy, physical medicine and rehabilitation, neurophysiology, muscle physiology, motor control, and biomechanics. The purpose of the meeting was to establish terminology and definitions for 4 aspects of motor disorders that occur in children: weakness, reduced selective motor control, ataxia, and deficits of praxis. The purpose of the definitions is to assist communication between clinicians, select homogeneous groups of children for clinical research trials, facilitate the development of rating scales to assess improvement or deterioration with time, and eventually to better match individual children with specific therapies. “Weakness” is defined as the inability to generate normal voluntary force in a muscle or normal voluntary torque about a joint. “Reduced selective motor control” is defined as the impaired ability to isolate the activation of muscles in a selected pattern in response to demands of a voluntary posture or movement. “Ataxia” is defined as an inability to generate a normal or expected voluntary movement trajectory that cannot be attributed to weakness or involuntary muscle activity about the affected joints. “Apraxia” is defined as an impairment in the ability to accomplish previously learned and performed complex motor actions that is not explained by ataxia, reduced selective motor control, weakness, or involuntary motor activity. “Developmental dyspraxia” is defined as a failure to have ever acquired the ability to perform age-appropriate complex motor actions that is not explained by the presence of inadequate demonstration or practice, ataxia, reduced selective motor control, weakness, or involuntary motor activity.

Selective Control Assessment of the Lower Extremity (SCALE): development, validation, and interrater reliability of a clinical tool for patients with cerebral palsy

Normal selective voluntary motor control (SVMC) can be defined as the ability to perform isolated joint movement without using mass flexor/extensor patterns or undesired movement at other joints, such as mirroring. SVMC is an important determinant of function, yet a valid, reliable assessment tool is lacking. The Selective Control Assessment of the Lower Extremity (SCALE) is a clinical tool developed to quantify SVMC in patients with cerebral palsy (CP). This paper describes the development, utility, validation, and interrater reliability of SCALE. Content validity was based on review by 14 experienced clinicians. Mean agreement was 91.9% (range 71.4–100%) for statements about content, administration, and grading. SCALE scores were compared with Gross Motor Function Classification System Expanded and Revised (GMFCS‐ER) levels for 51 participants with spastic diplegic, hemiplegic, and quadriplegic CP (GMFCS levels I – IV, 21 males, 30 females; mean age 11y 11mo [SD 4y 9mo]; range 5–23y). Construct validity was supported by significant inverse correlation (Spearmans r=‐0.83, p<0.001) between SCALE scores and GMFCS levels. Six clinicians rated 20 participants with spastic CP (seven males, 13 females, mean age 12y 3mo [SD 5y 5mo], range 7–23y) using SCALE. A high level of interrater reliability was demonstrated by intraclass correlation coefficients ranging from 0.88 to 0.91 (p<0.001).

Sensitivity of the pendulum test for assessing spasticity in persons with cerebral palsy

The sensitivity of the pendulum test to variation in spasticity in persons with spastic cerebral palsy (CP) was tested in 30 participants with CP and 10 participants without CP (controls) (mean age 13.8 years). The participants with CP were classified into three groups, with normal (mean age 15.9 years), mild/moderate (13.0 years), or severe (23.0 years) muscle tone, as assessed clinically using a modified Ashworth scale. Joint motion during the pendulum test was measured with an electrogoniometer. Muscle relaxation was confirmed using surface EMG. Outcome measures from the pendulum test were (1) number of oscillations, (2) duration of oscillations, (3) excursion of the first backward swing, and (4) relaxation index (first swing excursion/difference between the starting and resting angles). Data were assessed using one‐way analysis of variance. Outcome measures 1 to 3 differed significantly between control participants and participants with CP (p<0.05). The first swing excursion was the best predictor of the degree of spasticity in persons with CP, being significantly different between all groups (p<0.05). The number of oscillations and their duration differentiated between control participants and all participants with CP (p<0.05) but not between participants with CP who had mild/moderate versus severe spasticity (p>0.05). The relaxation index was not a sensitive measure (p>0.05 between most study groups). We conclude that the pendulum test is a valid tool for assessing spasticity in persons with CP and that the first swing excursion is the most sensitive outcome measure.

Relationship between ankle muscle and joint kinetics during the stance phase of locomotion in the cat.

The purpose of this study was to examine the relationship between internal force production in selected skeletal muscles and the externally calculated joint moment during overground locomotion in the adult cat. Hindlimb segments were modelled as a linked system of rigid bodies and a generalized muscle moment (GMM), the sum over all active and passive tissues acting about the joint, was calculated using principles of inverse dynamics. Moments produced by individual muscles were calculated using tendon transducers implanted in freely moving cats and muscle moment arm information. Results indicated that the externally measured variables of peak ground reaction force and joint position were equally important to the determination of peak ankle GMM. Examination of peak moments revealed that increases in peak ankle GMM were met by increases in medial (MG) and lateral (LG) gastrocnemius output. Peak soleus (SOL) moments did not change significantly as a function of peak ankle GMM. The role of the plantaris (PLT) was less clear, with peak moments increasing significantly as a function of peak ankle GMM in one cat. All four ankle extensors were important to the attainment of peak ankle GMM early in stance. Subsequently, SOL and PLT contributed substantially to the ankle GMM throughout stance, LG moments declined to near zero, soon after peak ankle GMM; and MG moments demonstrated a substantial but more gradual decline. The relative contributions of these individual muscles to the ankle GMM were supported by their respective architecture, uniarticular versus multiarticular function, and physiological profiles.

The effect of lower extremity selective voluntary motor control on interjoint coordination during gait in children with spastic diplegic cerebral palsy

Damage to motor tracts in the periventricular white matter is a primary etiology in spastic diplegic cerebral palsy (CP). These tracts are responsible for the production of selective voluntary motor control (SVMC). Lower extremity motor control has been suggested as being an important predictor of improvement following interventions. While there are multiple impairments in spastic CP, the inability to perform purposeful voluntary movement is a critical factor in determining functional ability that merits investigation. The purpose of this study was to examine the relationship between SVMC ability and hip and knee coordination during the swing phase of gait in participants with spastic CP. Gait analysis and SVMC assessments were conducted for 15 participants with CP. Relative phase analysis was used to calculate the minimum relative phase (MRP) angle during swing; a measurement of interjoint coordination between the hip and the knee. SVMC ability was measured using the Selective Control Assessment of the Lower Extremity (SCALE) tool. Significant correlations were found between SCALE scores and both MRP values (p<0.0001) and duration of out-of-phase movement (p<0.005) during swing. These findings supported our hypothesis that SVMC ability is related to a patients ability to move in an uncoupled pattern during the swing phase of gait (i.e., extending the knee while flexing the hip). An understanding of influence of SVMC on swing phase gait mechanics may help establish appropriate goals for interventions, in particular hamstring lengthenings.

Pediatric Endurance and Limb Strengthening (PEDALS) for Children With Cerebral Palsy Using Stationary Cycling: A Randomized Controlled Trial

Background Effective interventions to improve and maintain strength (force-generating capacity) and endurance are needed for children with cerebral palsy (CP). Objective This study was performed to examine the effects of a stationary cycling intervention on muscle strength, locomotor endurance, preferred walking speed, and gross motor function in children with spastic diplegic CP. Design This was a phase I randomized controlled trial with single blinding. Setting The interventions were performed in community-based outpatient physical therapy clinics. Outcome assessments were performed in university laboratories. Participants Sixty-two ambulatory children aged 7 to 18 years with spastic diplegic CP and Gross Motor Function Classification System levels I to III participated in this study. Intervention and Measurements Participants were randomly assigned to cycling or control (no-intervention) groups. Thirty intervention sessions occurred over 12 weeks. Primary outcomes were peak knee extensor and flexor moments, the 600-Yard Walk-Run Test, the Thirty-Second Walk Test, and the Gross Motor Function Measure sections D and E (GMFM-66). Results Significant baseline-postintervention improvements were found for the 600-Yard Walk-Run Test, the GMFM-66, peak knee extensor moments at 120°/s, and peak knee flexor moments at 30°/s for the cycling group. Improved peak knee flexor moments at 120°/s were found for the control group only, although not all participants could complete this speed of testing. Significant differences between the cycling and control groups based on change scores were not found for any outcomes. Limitations Heterogeneity of the patient population and intrasubject variability were limitations of the study. Conclusions Significant improvements in locomotor endurance, gross motor function, and some measures of strength were found for the cycling group but not the control group, providing preliminary support for this intervention. As statistical differences were not found in baseline-postintervention change scores between the 2 groups; the results did not demonstrate that stationary cycling was more effective than no intervention. The results of this phase I study provide guidance for future research.

Lower-extremity selective voluntary motor control in patients with spastic cerebral palsy: increased distal motor impairment

Aim  Multiple impairments contribute to motor deficits in spastic cerebral palsy (CP). Selective voluntary motor control (SVMC), namely isolation of joint movement upon request, is important, but frequently overlooked. This study evaluated the proximal to distal distribution of SVMC impairment among lower extremity joints.

Identification of a Core Set of Exercise Tests for Children and Adolescents with Cerebral Palsy: A Delphi Survey of Researchers and Clinicians.

Aim  Evidence‐based recommendations regarding which exercise tests to use in children and adolescents with cerebral palsy (CP) are lacking. This makes it very difficult for therapists and researchers to choose the appropriate exercise‐related outcome measures for this group. This study aimed to identify a core set of exercise tests for children and adolescents with CP.