Prefrontal cortex hemodynamic activity during a test of lower extremity functional muscle strength in children with cerebral palsy: A functional near-infrared spectroscopy study.

Children with cerebral palsy (CP) exhibit impaired motor control and significant muscle weakness due to a brain lesion. However, studies that assess the relationship between brain activity and performance on dynamic functional muscle strength assessments in CP are needed. The aim of this study was to determine the effect of a progressive lateral step-up test on prefrontal cortex (PFC) hemodynamic activity in children with CP. Fourteen ambulatory children with spastic CP (Gross Motor Function Classification System level I; 5-11 y) and 14 age- and sex-matched typically developing control children completed a progressive lateral step-up test at incremental step heights (0, 10, 15 and 20 cm) using their non-dominant lower limb. Hemodynamic activity in the PFC was assessed using non-invasive, portable functional neuroimaging (functional near-infrared spectroscopy). Children with CP completed fewer repetitions at each step height and exhibited lower PFC hemodynamic activity across step heights compared to controls. Lower PFC activation in CP was maintained after statistically controlling for the number of repetitions completed at each step height. PFC hemodynamic activity was not associated with LSUT task performance in children with CP, but a positive relationship was observed in controls at the most challenging 20 cm step height. The results suggest there is an altered PFC recruitment pattern in children with CP during a highly dynamic test of functional strength. Further studies are needed to explore the mechanisms underlying the suppressed PFC activation observed in children with CP compared to typically developing children.

Mental health, physical activity, and sports among children with cerebral palsy.

BACKGROUND: People with cerebral palsy (CP) may be at an increased risk for mental health disorders due to co-occurring physical and communication limitations associated with the condition. Participation in physical activity (PA) and sports may provide opportunities to increase socialization and improve physical function. The purpose of this study was to examine associations between participation in daily PA and sports and mental health among children with CP. METHOD: Participants included children with CP (n = 458) and typically developing children (TDC) (n = 40 091) 6-17 years whose parents participated in the 2016-2020 National Survey of Children's Health. Mental health disorders included anxiety, depression, behavioural disorders and attention-deficit/hyperactivity disorder (ADHD). RESULTS: Compared with TDC, children with CP had a higher prevalence of mental health disorders (75.5% vs. 54.2%) and were more likely to receive mental health care (21.5% vs. 14.6%). Controlling for sociodemographic variables, children with CP were more likely to experience anxiety [odds ratio (OR) 2.6; 95% confidence interval (CI) = 2.1-3.3), depression (OR 1.8; 95% CI 1.3-2.4), behavioural disorders (OR 4.8; 95% CI 3.8-6.0) and ADHD (OR 2.1; 95% CI 1.6-2.6). The likelihood of these conditions decreased when children participated in sports for anxiety (OR 2.2; 95% CI 1.8-2.8), depression (OR = 1.4; 95% CI 1.0-2.0), behavioural disorders (OR 4.1; 95% CI 3.2-5.1) and ADHD (OR 1.9; 95% CI 1.5-2.5). The likelihood for anxiety (OR 2.3; 95% CI 1.8-2.8), depression (OR 1.4; 95% CI 1.0-1.9), behavioural disorders (OR 4.4; 95% CI 3.5-5.5) and ADHD (OR 1.9; 95% CI 1.5-2.4) also decreased with participation in daily PA. CONCLUSIONS: There is an overwhelming disparity in the number of children with CP who have a mental health disorder and those who receive mental health care. Increasing access to participation in sports and PA may be beneficial.

Anteroposterior balance reactions in children with spastic cerebral palsy.

AIM: To compare anterior and posterior standing balance reactions, as measured by single-stepping thresholds, in children with and without spastic cerebral palsy (CP). METHOD: Seventeen ambulatory children with spastic CP (eight males, nine females) and 28 typically developing children (13 males, 15 females; age range 5-12y, mean [SD] 9y 2mo [2y 3mo]), were included in this cross-sectional, observational study. Balance reaction skill was quantified as anterior and posterior single-stepping thresholds, or the treadmill-induced perturbations that consistently elicited a step in that direction. In order to understand the underlying mechanisms of between-group differences in stepping thresholds, dynamic stability was quantified using the minimum margin of stability. Ankle muscle activation latency, magnitude, and co-contraction were assessed with surface electromyography. RESULTS: We observed an age and group interaction for anterior thresholds (p=0.001, partial η2 =0.24). At older (≈11y; p<0.001, partial η2 =0.48), but not younger (≈7y; p=0.33, partial η2 =0.02) ages, typically developing children had larger anterior thresholds than those with CP. In response to near-threshold anterior perturbations, older typically developing children recovered from more instability than their peers with CP (p=0.004, partial η2 =0.18). Older children had no between-group differences in ankle muscle activity. No between-group differences were observed in posterior thresholds. INTERPRETATION: The effects of CP on balance reactions are age- and direction-specific. Older typically developing children are more able or willing to withhold a step when unstable. WHAT THIS PAPER ADDS: Children with spastic cerebral palsy have age- and direction-specific balance-reaction impairments. Lower anterior stepping thresholds were observed in older, but not younger children. Older typically developing children withheld a forward step at higher levels of instability. No between-group differences were seen in posterior stepping thresholds.

Complicated Muscle-Bone Interactions in Children with Cerebral Palsy.

PURPOSE OF REVIEW: The goal of this review is to highlight the deficits in muscle and bone in children with cerebral palsy (CP), discuss the muscle-bone relationship in the CP population, and identify muscle-based intervention strategies that may stimulate an improvement in their bone development. RECENT FINDINGS: The latest research suggests that muscle and bone are both severely underdeveloped and weak in children with CP, even in ambulatory children with mild forms of the disorder. The small and low-performing muscles and limited participation in physical activity are likely the major contributors to the poor bone development in children with CP. However, the muscle-bone relationship may be complicated by other factors, such as a high degree of fat and collagen infiltration of muscle, atypical muscle activation, and muscle spasticity. Muscle-based interventions, such as resistance training, vibration, and nutritional supplementation, have the potential to improve bone development in children with CP, especially if they are initiated before puberty. Studies are needed to identify the muscle-related factors with the greatest influence on bone development in children with CP. Identifying treatment strategies that capitalize on the relationship between muscle and bone, while also improving balance, coordination, and physical activity participation, is an important step toward increasing bone strength and minimizing fractures in children with CP.

Greater Visceral Fat but No Difference in Measures of Total Body Fat in Ambulatory Children With Spastic Cerebral Palsy Compared to Typically Developing Children.

BACKGROUND: Individuals with cerebral palsy (CP) are at increased risk for obesity and obesity-related complications. Studies of total body fat in those with CP are inconsistent and studies of abdominal fat are lacking in children with CP. The objective of this study was to determine if ambulatory children with spastic CP have greater central adiposity compared to typically developing children. METHODOLOGY: Eighteen ambulatory children with spastic CP (n = 5 girls; 8.6 ± 2.9 yr) and 18 age-, sex-, and race-matched typically developing children (controls; 8.9 ± 2.1 yr) participated in this cross-sectional study. Children with CP were classified as I or II using the Gross Motor Function Classification System. Dual-energy X-ray absorptiometry assessed body composition, including total body, trunk and abdominal fat mass, fat-free mass, fat mass index (FMI), and fat-free mass index (FFMI). RESULTS: There were no group differences in fat mass, fat-free mass, FMI, and FFMI in the total body, fat mass, fat-free mass, and FFMI in the trunk, or fat mass, visceral fat mass, and subcutaneous fat mass in the abdomen (p > 0.05). Compared to controls, children with CP had higher trunk FMI, abdominal FMI, and visceral FMI (p < 0.05). Although marginally insignificant (p = 0.088), children with CP had higher subcutaneous FMI. CONCLUSIONS: Ambulatory children with spastic CP have elevated central adiposity, especially in the visceral region, despite no differences in measures of total body fat. How this relates to cardiometabolic disease progression in those with CP requires further investigation.

The effect of zoledronic acid on attenuation of bone loss at the hip and knee following acute traumatic spinal cord injury: a randomized-controlled study.

STUDY DESIGN: Randomized double blind, placebo-controlled trial. OBJECTIVES: To examine the effect of early intravenous zoledronic acid (ZA) on bone markers and areal bone mineral density (aBMD) in persons with acute ASIA Impairment Scale (AIS) A traumatic spinal cord injury (SCI). SETTING: Two inpatient rehabilitation units. METHODS: Thirteen men, 2 women, aged 19-65, C4-T10 AIS A SCI, received 5 mg intravenous ZA vs. placebo 12-21 days post injury. Markers of bone formation (procollagen N-1 terminal propeptide [P1NP]), bone resorption (serum C-telopeptide [CTX]), and aBMD by dual-energy X-ray absorptiometry (DXA) for hip (femur-proximal, intertrochanteric, neck), and knee (distal femur, proximal tibia) were obtained at baseline, 2 weeks post infusion (P1NP, CTX only), 4 and 12 months post injury. RESULTS: P1NP remained unchanged, while CTX decreased in ZA but increased in controls at 2 weeks (mean difference = -97%, p < 0.01), 4 months (mean difference = -54%, p < 0.05), but not 12 months (mean difference = 3%, p = 0.23). Changes in aBMD at the hip favored ZA at 4 months (mean difference 10.3-14.1%, p < 0.01) and 12 months (mean difference 10.8-13.1%, p < 0.02). At 4 months, changes in aBMD favored ZA at the distal femur (mean difference 6.0%, 95% CI: 0.7-11.2, p < 0.03) but not proximal tibia (mean difference 8.3%, 95% CI: -6.9 to 23.6, p < 0.23). Both groups declined in aBMD at 12 months, with no between group differences. CONCLUSION: ZA administered ≤21 days of complete traumatic SCI maintains aBMD at the hip and distal femur at 4 months post injury. This effect is partially maintained at 12 months.

BMI does not capture the high fat mass index and low fat-free mass index in children with cerebral palsy and proposed statistical models that improve this accuracy.

BACKGROUND/OBJECTIVES: Children with cerebral palsy (CP) are at risk for having a misclassified overweight/obesity status based on BMI thresholds due to their lower fat-free mass and similar fat mass compared with typically developing children. The primary objective was to determine if BMI could predict fat mass index (FMI) and fat-free mass index (FFMI) in children with CP. SUBJECTS/METHODS: Forty-two children with CP and 42 typically developing children matched to children with CP for age and sex participated in the study. Dual-energy X-ray absorptiometry was used to assess body composition. Children with CP who could ambulate without assistance were considered ambulatory (ACP) and the rest were considered nonambulatory (NACP). RESULTS: Children with CP had higher percent body fat (%Fat) and FMI and lower fat-free mass and FFMI than controls (p < 0.05) but no difference in fat mass (p = 0.10). When BMI was statistically controlled, NACP had higher %Fat, fat mass and FMI and lower FFMI than ACP and controls (p < 0.05). NACP also had lower fat-free mass than controls (p < 0.05). ACP had higher %Fat and FMI and lower fat-free mass and FFMI than controls (p < 0.05). BMI was a strong predictor of FMI (r2 = 0.83) and a moderately strong predictor of FFMI (r2 = 0.49) in children with CP (both p < 0.01). Prediction of FMI (R2 = 0.86) and FFMI (R2 = 0.66) from BMI increased (p < 0.05) when age, sex and ambulatory status were included. CONCLUSION: Compared with typically developing children, children with CP have a higher FMI and lower FFMI for a given BMI, which is more pronounced in NACP than ACP. The finding suggests that the prevalence of overweight/obesity status may be underestimated in children with CP.

Statistical Models to Assess Leg Muscle Mass in Ambulatory Children With Spastic Cerebral Palsy Using Dual-Energy X-Ray Absorptiometry.

Cerebral palsy (CP) is a movement disorder associated with small and weak muscles. Methods that accurately assess muscle mass in children with CP are scarce. The purpose of this study was to determine whether dual-energy X-ray absorptiometry (DXA) accurately estimates midleg muscle mass in ambulatory children with spastic CP. Ambulatory children with spastic CP and typically developing children 5-11 y were studied (n = 15/group). Fat-free soft tissue mass (FFST) and fat mass at the middle third of the tibia (i.e., midleg) were estimated using DXA. Muscle mass (muscleMRI) and muscle mass corrected for intramuscular fat (muscleMRIfc) in the midleg were estimated using magnetic resonance imaging (MRI). Statistical models were created to predict muscleMRI and muscleMRIfc using DXA. Children with CP compared to typically developing children had lower FFST (38%), muscleMRI (40%) and muscleMRIfc (47%) (all p < 0.05) and a lower ratio of muscleMRIfc to FFST (17%, p < 0.05). DXA-based models developed using data from typically developing children overestimated muscleMRI (13%) and muscleMRIfc (22%) (both p < 0.05) in children with CP. DXA-based models developed using data from children with CP explained 91% of the variance in muscleMRI and 90% of the variance in muscleMRIfc in children with CP (both p < 0.05). Moreover, the estimates were not different from muscleMRI and muscleMRIfc (both p > 0.99). We conclude that DXA-based statistical models accurately estimate midleg muscle mass in children with CP when the models are composed using data from children with CP rather than typically developing children.

Obese Versus Normal-Weight Late-Adolescent Females have Inferior Trabecular Bone Microarchitecture: A Pilot Case-Control Study.

Though still a topic of debate, the position that skeletal health is compromised with obesity has received support in the pediatric and adult literature. The limited data relating specifically to trabecular bone microarchitecture, however, have been relatively inconsistent. The aim of this pilot cross-sectional case-control study was to compare trabecular bone microarchitecture between obese (OB) and normal-weight (NW) late-adolescent females. A secondary aim was to compare diaphyseal cortical bone outcomes between these two groups. Twenty-four non-Hispanic white females, ages 18-19 years, were recruited into OB (n = 12) or NW (n = 12) groups based on pre-specified criteria for percent body fat (≥32 vs. <30, respectively), body mass index (>90th vs. 20th-79th, respectively), and waist circumference (≥90th vs. 25th-75th, respectively). Participants were also individually matched on age, height, and oral contraceptive use. Using magnetic resonance imaging, trabecular bone microarchitecture was assessed at the distal radius and proximal tibia metaphysis, and cortical bone architecture was assessed at the mid-radius and mid-tibia diaphysis. OB versus NW had lower apparent trabecular thickness (radius and tibia), higher apparent trabecular separation (radius), and lower apparent bone volume to total volume (radius; all P < 0.050). Some differences in radius and tibia trabecular bone microarchitecture were retained after adjusting for insulin resistance or age at menarche. Mid-radius and mid-tibia cortical bone volume and estimated strength were lower in the OB compared to NW after adjusting for fat-free soft tissue mass (all P < 0.050). These trabecular and cortical bone deficits might contribute to the increased fracture risk in obese youth.

Site-Specific Transmission of a Floor-Based, High-Frequency, Low-Magnitude Vibration Stimulus in Children With Spastic Cerebral Palsy.

OBJECTIVE: To determine the degree to which a high-frequency, low-magnitude vibration signal emitted by a floor-based platform transmits to the distal tibia and distal femur of children with spastic cerebral palsy (CP) during standing. DESIGN: Cross-sectional study. SETTING: University research laboratory. PARTICIPANTS: Children with spastic CP who could stand independently (n=18) and typically developing children (n=10) (age range, 4-12y) participated in the study (N=28). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The vibration signal at the high-frequency, low-magnitude vibration platform (approximately 33Hz and 0.3g), distal tibia, and distal femur was measured using accelerometers. The degree of plantar flexor spasticity was assessed using the Modified Ashworth Scale. RESULTS: The high-frequency, low-magnitude vibration signal was greater (P<.001) at the distal tibia than at the platform in children with CP (.36±.06g vs .29±.05g) and controls (.40±.09g vs .24±.07g). Although the vibration signal was also higher at the distal femur (.35±.09g, P<.001) than at the platform in controls, it was lower in children with CP (.20±.07g, P<.001). The degree of spasticity was negatively related to the vibration signal transmitted to the distal tibia (Spearman ρ=-.547) and distal femur (Spearman ρ=-.566) in children with CP (both P<.05). CONCLUSIONS: A high-frequency, low-magnitude vibration signal from a floor-based platform was amplified at the distal tibia, attenuated at the distal femur, and inversely related to the degree of muscle spasticity in children with spastic CP. Whether this transmission pattern affects the adaptation of the bones of children with CP to high-frequency, low-magnitude vibration requires further investigation.

Musculoskeletal Effects of 2 Functional Electrical Stimulation Cycling Paradigms Conducted at Different Cadences for People With Spinal Cord Injury: A Pilot Study.

OBJECTIVE: To compare the musculoskeletal effects of low cadence cycling with functional electrical stimulation (FES) with high cadence FES cycling for people with spinal cord injury (SCI). DESIGN: Randomized pre-post design. SETTING: Outpatient rehabilitation clinic. PARTICIPANTS: Participants (N=17; 14 men, 3 women; age range, 22-67y) with C4-T6 motor complete chronic SCI were randomized to low cadence cycling (n=9) or high cadence cycling (n=8). INTERVENTIONS: Low cadence cycling at 20 revolutions per minute (RPM) and high cadence cycling at 50 RPM 3 times per week for 6 months. Cycling torque (resistance per pedal rotation) increased if targeted cycling cadence was maintained. MAIN OUTCOME MEASURES: Dual-energy x-ray absorptiometry was used to assess distal femur areal bone mineral density, magnetic resonance imaging was used to assess to assess trabecular bone microarchitecture and cortical bone macroarchitecture and thigh muscle volume, and biochemical markers were used to assess bone turnover. It was hypothesized that subjects using low cadence cycling would cycle with greater torque and therefore show greater musculoskeletal improvements than subjects using high cadence cycling. RESULTS: A total of 15 participants completed the study. Low cadence cycling obtained a maximal average torque of 2.9±2.8Nm, and high cadence cycling obtained a maximal average torque of 0.8±0.2Nm. Low cadence cycling showed greater decreases in bone-specific alkaline phosphatase, indicating less bone formation (15.5% decrease for low cadence cycling, 10.7% increase for high cadence cycling). N-telopeptide decreased 34% following low cadence cycling, indicating decreased resorption. Both groups increased muscle volume (low cadence cycling by 19%, high cadence cycling by 10%). Low cadence cycling resulted in a nonsignificant 7% increase in apparent trabecular number (P=.08) and 6% decrease in apparent trabecular separation (P=.08) in the distal femur, whereas high cadence cycling resulted in a nonsignificant (P>.3) 2% decrease and 3% increase, respectively. CONCLUSIONS: This study suggests that the greater torque achieved with low cadence cycling may result in improved bone health because of decreased bone turnover and improved trabecular bone microarchitecture. Longer-term outcome studies are warranted to identify the effect on fracture risk.

Load-specific physical activity scores are related to tibia bone architecture.

Assessment of physical activity in clinical bone studies is essential. Two bone-specific physical activity scoring methods, the Bone Loading History Questionnaire (BLHQ) and Bone-Specific Physical Activity Questionnaire (BPAQ), have shown correlations with bone density and geometry, but not architecture. The purpose of this study was to determine relationships between physical activity scoring methods and bone architecture in non-Hispanic white adolescent females (N = 24; 18-19 years of age). Bone loading scores (BLHQ [hip and spine] and past BPAQ) and energy expenditure (7-day physical activity recall) were determined from respective questionnaires. Estimates of trabecular and cortical bone architecture at the nondominant radius and tibia were assessed via magnetic resonance imaging. Total body and regional areal bone mineral density (aBMD), as well as total body fat mass and fat-free soft tissue (FFST) mass were assessed via dual energy X-ray absorptiometry. Pearson's correlations and partial correlations adjusting for height, total body fat mass, and FFST were performed. Hip BLHQ scores were correlated with midtibia cortical volume (r = .43; p = .03). Adjusted hip and spine BLHQ scores were correlated with all midtibia cortical measures (r = .50-0.58; p < .05) and distal radius apparent trabecular number (r = .46-0.53; p < .05). BPAQ scores were correlated with all midtibia cortical (r = .41-0.51; p < .05) and most aBMD (r = .47-0.53; p < .05) measures. Energy expenditure was inversely associated with femoral neck aBMD only after statistical adjustment (r = .49, p < .05). These data show that greater load-specific physical activity scores, but not energy expenditure, are indicative of greater midtibia cortical bone quality, thus supporting the utility of these instruments in musculoskeletal research.

Elevated blood pressure in children with cerebral palsy and its relationship with adiposity and physical activity.

BACKGROUND: There is a high prevalance of hypertension in adults with with cerebral palsy (CP). However, less is known about blood pressure in children with CP. OBJECTIVE: The aim was to determine if blood pressure is elevated in children with CP and whether it is related to adiposity and physical activity. METHODS: Thirty children with spastic CP (5-11 y) and 30 age-, sex-, and race-matched typically developing control children were studied. Resting systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate were measured, and mean arterial pressure (MAP) was calculated. Visceral fat mass and total body fat mass index (FMI) were determined using dual-energy X-ray absorptiometry. Physical activity was assessed using accelerometer-based monitors. RESULTS: Children with CP had higher DBP and heart rate than controls (p < 0.05). DBP percentile and MAP were also higher in children with CP when BMI was statistically controlled. Children with CP and elevated blood pressure or hypertension (n = 8) had 56% more visceral fat mass than children with CP and normal blood pressure (n = 22; p < 0.05). In the groups combined, blood pressure was directly related to visceral fat mass and FMI, and inversely related to physical activity (p < 0.05). However, in children with CP alone, only visceral fat mass was related to blood pressure (p < 0.05). CONCLUSIONS: Children with CP have higher resting blood pressure than typically developing children. The higher blood pressure is related to higher visceral adiposity. Careful blood pressure screening should start during childhood in individuals with CP.

Estimates of functional muscle strength from a novel progressive lateral step-up test are feasible, reliable, and related to physical activity in children with cerebral palsy.

OBJECTIVE: To determine if estimates of functional muscle strength from a novel progressive lateral-step-up test (LSUT) are feasible, reliable, and related to physical activity in children with cerebral palsy (CP). DESIGN: Cross-sectional; test-retest reliability Subjects/Patients: Children with CP and typically developing control children (n = 45/group). METHODS: An LSUT with 10, 15, and 20 cm step heights was completed. It was repeated 4 weeks later in 20 children with CP. A composite score of LSUT was calculated based on the step height and number of repetitions completed. Physical activity was assessed using monitors worn on the ankle and hip. RESULTS: Only 4 (13%) of the children with CP were unable to complete a lateral step-up repetition without assistance. All children were able to complete at least 1 repetition with assistance, though more than twice as many children with CP required assistance at 15 and 20 cm step heights than at the 10 cm step height (p < 0.01). Children with CP had 59 to 63% lower LSUT performance, 37% lower physical activity assessed at the ankle, and 22% lower physical activity assessed at the hip than controls (all p < 0.01). The intra-class correlation coefficient ranged from 0.91 to 0.96 for LSUT performance at the different step heights and was 0.97 for the composite score. All LSUT performance measures were positively related to ankle physical activity in children with CP (r range = 0.43 to 0.47, all p < 0.01). Only performance at 20 cm and the composite score were positively related to hip physical activity (r = 0.33 and 0.31, respectively, both p < 0.05). The relationship between the LSUT performance and physical activity at both the ankle and hip increased when age and sex were statistically controlled (model r range = 0.55 to 0.60, all p < 0.001). CONCLUSION: Estimates of functional muscle strength from a novel progressive LSUT are feasible, reliable, and positively related to physical activity in children with CP.

A Cross-Sectional Study of Disparities in Healthcare Transition in Cerebral Palsy.

Background: Cerebral palsy (CP) is the most common physical disability among children, affecting their lifespan. While CP is typically nonprogressive, symptoms can worsen over time. With advancements in healthcare, more children with CP are reaching adulthood, creating a greater demand for adult care. However, a significant lack of adult healthcare providers exists, as CP is predominantly considered a pediatric condition. This study compares the transition experiences of children with CP compared to those with other developmental disabilities (DDs) and typically developing children (TDC). Methods: This study utilizes cross-sectional data from the National Survey of Children's Health (NSCH) from 2016-2020, including 71,973 respondents aged 12-17. Children were categorized into three groups: CP (n = 263), DD (n = 9460), and TDC (n = 36,053). The analysis focused on the receipt of transition services and identified demographic and socioeconomic factors influencing these services. Results: Only 9.7% of children with CP received necessary transition services, compared to 19.7% of children with DDs and 19.0% of TDC. Older age, female sex, non-Hispanic white ethnicity, and higher household income were significant predictors of receiving transition services. Children with CP were less likely to have private time with healthcare providers and receive skills development assistance compared to other groups. Conclusions: The findings highlight disparities and critical needs for targeted interventions and structured transition programs to improve the transition from pediatric to adult healthcare for children with CP. Addressing disparities in service receipt and ensuring coordinated, continuous care are essential for improving outcomes for children with CP.

Jump Performance and Its Relationship with Lower Body Joint Kinetics and Kinematics in Children with Cerebral Palsy.

PURPOSE: The aim was to quantify jump performance in children with cerebral palsy (CP) and determine if the expected deficit is related to their lower body joint kinetics and kinematics. METHODS: Twenty-four ambulatory ( n = 17 level I and 7 level II in the Gross Motor Function Classification System) children with spastic CP ( n = 13 unilateral and 11 bilateral) and 24 age-, sex-, and race-matched typically developing controls were studied. Jump height and peak power and range of motion at the hip, knee, and ankle of the more affected limb in children with CP and the nondominant limb in controls were assessed during a countermovement jump using three-dimensional motion capture and a force platform. RESULTS: Compared with controls, children with CP had lower jump height (33%, Cohen's d ( d ) = 1.217), peak power at the knee (39%, d = 1.013) and ankle (46%, d = 1.687), and range of motion at the hip (32%, d = 1.180), knee (39%, d = 2.067), and ankle (46%, d = 3.195; all P < 0.001). Jump height was positively related to hip, knee, and ankle power and range of motion in children with CP ( rs range = 0.474-0.613, P < 0.05), and hip and ankle power and knee and ankle range of motion in controls ( rs range = 0.458-0.630, P < 0.05). The group difference in jump height was no longer detected when ankle joint power, ankle range of motion, or knee range of motion was statistically controlled ( P > 0.15). CONCLUSIONS: Jump performance is compromised in children with CP and is associated with low power generation and range of motion in the lower limb, especially at the ankle.

Cardiometabolic Risk and Its Relationship With Visceral Adiposity in Children With Cerebral Palsy.

Context: Adults with cerebral palsy (CP) display a higher prevalence of cardiometabolic disease compared with the general population. Studies examining cardiometabolic disease risk in children with CP are limited. Objective: The purpose of this study was to determine if children with CP exhibit higher cardiometabolic risk than typically developing children, and to examine its relationship with visceral adiposity and physical activity. Methods: Thirty ambulatory children with CP and 30 age-, sex-, and race-matched typically developing control children were tested for blood lipids, glucose, and the homeostatic model assessment of insulin resistance (HOMA-IR). Visceral fat was assessed using dual-energy x-ray absorptiometry. Physical activity was assessed using accelerometer-based monitors. Results: Children with CP had higher total cholesterol, low-density lipoprotein cholesterol, and non-high-density lipoprotein cholesterol (non-HDL-C), glucose, prevalence of dyslipidemia, prevalence of prediabetes, and visceral fat mass index (VFMI) and lower physical activity than controls (all P < .05). In the groups combined, non-HDL-C and glucose were positively related to VFMI (r = 0.337 and 0.313, respectively, P < .05), and non-HDL-C and HOMA-IR were negatively related to physical activity (r = -0.411 and -0.368, respectively, P < .05). HOMA-IR was positively related to VFMI in children with CP (r = 0.698, P < .05), but not in controls. Glucose was not related to physical activity in children with CP, but it was negatively related in controls (r = -0.454, P < .05). Conclusion: Children with CP demonstrate early signs of cardiometabolic disease, which are more closely related to increased visceral adiposity than decreased physical activity.

Hip strength in adults with type 1 diabetes is associated with age at onset of diabetes.

We investigated the association of age at onset of type 1 diabetes with areal bone mineral density (aBMD), estimates of bone strength, and outer diameter. Using dual-energy X-ray absorptiometry (DXA), aBMD, axial strength (cross-sectional area [CSA]), bending strength (section modulus [SM]), and outer diameter at the narrow neck, intertrochanter, and shaft of the proximal femur were determined for 60 adults. Analysis of covariance (ANCOVA) was used to determine if the DXA-based measures of bone were related to age at onset and if this relationship differed by gender. Age at onset, gender, and the interaction of age at onset by gender were included in the ANCOVA models along with current age, duration, height, lean soft tissue mass, and hemoglobin A1c as covariates. In the adjusted models with CSA, SM, or outer diameter as the dependent variable, age at onset (p<0.01) and gender (p<0.0001) were significant with no interaction. For shaft aBMD, there was a significant age at onset by gender interaction (p=0.0285), where an earlier onset was associated with lower aBMD in the femoral shaft of females but not males. The findings suggest that an earlier onset of type 1 diabetes is associated with lower measures of bone strength and outer diameter.

Are muscle volume differences related to concentric muscle work during walking in spastic hemiplegic cerebral palsy?

BACKGROUND: Individuals with spastic hemiplegic cerebral palsy are typically high functioning and walk without assistive devices. The involved limb is usually smaller and shorter, although it is not clear whether the difference in muscle volume has an impact on walking capacity. QUESTIONS/PURPOSES: We determined the volume of muscles important for propulsion and related that volume to concentric muscle work during walking on the hemiplegic and noninvolved sides in patients with cerebral palsy. PATIENTS AND METHODS: We studied 46 patients (mean age, 17.6 years; range, 13-24 years) with spastic hemiplegic cerebral palsy. We assessed muscle volume using MRI and concentric muscle work in the sagittal plane from the hip, knee, and ankle using three-dimensional gait analysis. Patients were classified by Winters' criteria to assess the involvement of cerebral palsy and movement pattern during walking. RESULTS: On the hemiplegic side, muscles were smaller, except for the gracilis muscle, and concentric muscle work from the ankle plantar flexors, knee extensors, and hip flexors and extensors was lower compared to the noninvolved side. Hip extensor work was higher on the hemiplegic and the noninvolved sides compared to a control group of 14 subjects without cerebral palsy. Hemiplegic to noninvolved volume ratios correlated with work ratios (r = 0.40-0.66). The Winters classification and previous calf muscle surgery predicted work ratios. CONCLUSIONS: Our observations of smaller muscles on the hemiplegic side and changes in muscle work on both sides can help us distinguish between primary deviations that may potentially be treatable and compensatory mechanisms that should not be treated.