Human lower leg muscles grow asynchronously.

Muscle volume must increase substantially during childhood growth to generate the power required to propel the growing body. One unresolved but fundamental question about childhood muscle growth is whether muscles grow at equal rates; that is, if muscles grow in synchrony with each other. In this study, we used magnetic resonance imaging (MRI) and advances in artificial intelligence methods (deep learning) for medical image segmentation to investigate whether human lower leg muscles grow in synchrony. Muscle volumes were measured in 10 lower leg muscles in 208 typically developing children (eight infants aged less than 3 months and 200 children aged 5 to 15 years). We tested the hypothesis that human lower leg muscles grow synchronously by investigating whether the volume of individual lower leg muscles, expressed as a proportion of total lower leg muscle volume, remains constant with age. There were substantial age-related changes in the relative volume of most muscles in both boys and girls (p < 0.001). This was most evident between birth and five years of age but was still evident after five years. The medial gastrocnemius and soleus muscles, the largest muscles in infancy, grew faster than other muscles in the first five years. The findings demonstrate that muscles in the human lower leg grow asynchronously. This finding may assist early detection of atypical growth and allow targeted muscle-specific interventions to improve the quality of life, particularly for children with neuromotor conditions such as cerebral palsy.

Non-attendance at outpatient clinic appointments by children with cerebral palsy.

AIM: To determine factors that influence non-attendance at outpatient clinics by children with cerebral palsy (CP). METHOD: This was a retrospective cohort study of 1395 children with CP (59.6% male; born 2005 to 2017) identified from the New South Wales (NSW)/Australian Capital Territory CP Register, who had scheduled appointments at outpatient clinics at two NSW tertiary paediatric hospitals between 2012 and 2019. Associations between sociodemographic, clinical, and process-of-care factors and non-attendance were examined using multivariate logistic regression with generalized estimating equations. RESULTS: A total of 5773 (12%) of 50 121 scheduled outpatient days were not attended. Non-attendance increased over time (average increase 5.6% per year, 95% confidence interval [CI]: 3.7-7.3). Older children aged 5 to 9 years (adjusted odds ratio [aOR] 1.11; 95% CI: 1.02-1.22) and 10 to 14 years (aOR 1.17; 95% CI: 1.03-1.34), socioeconomic disadvantage (aOR 1.29; 95% CI: 1.11-1.50), previous non-attendance (aOR 1.38; 95% CI: 1.23-1.53), and recent rescheduled or cancelled appointments (aOR 1.08; 95% CI: 1.01-1.16) were associated with increased likelihood of non-attendance. INTERPRETATION: One in eight outpatient appointments for children with CP were not attended. Non-attendance was associated with increasing age, socioeconomic disadvantage, previous non-attendance, and recent rescheduled or cancelled appointments. Identifying specific barriers and interventions to improve access to outpatient services for these groups is needed. WHAT THIS PAPER ADDS: Twelve per cent of scheduled appointments for children with cerebral palsy are not attended. Proportions of appointments not attended has increased over the last decade. Increasing age and socioeconomic disadvantage increase the likelihood of non-attendance. Previous non-attendance and recent cancelled or rescheduled appointments increase the likelihood of further non-attendance.

Acute and Chronic Pain in Children and Adolescents With Cerebral Palsy: Prevalence, Interference, and Management.

OBJECTIVE: To determine the prevalence, interference, and management of acute and chronic pain among youth with cerebral palsy (CP) aged 5-18 years attending outpatient rehabilitation services. DESIGN: A cross-sectional study using the Faces Pain Scale-Revised, Patient Reporting Outcomes Measurement Information System Pediatric Pain Interference Scale, and the Cerebral Palsy Quality of Life questionnaire. Where children were unable to self-report, parent or caregiver proxy was obtained. SETTING: Outpatient rehabilitation. PARTICIPANTS: Participants (N=280) with CP aged 5-18 years and their parent or caregiver. Self-report was obtained by 45.7% (n=128) and proxy-report was obtained by 54.3% (n=152) of the cohort. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Presence or absence of acute pain and chronic pain. Secondary measures were pain intensity, pain interference, pain management, and quality of life. RESULTS: Acute pain and chronic pain were reported by 67.1% and 31.4% of participants, respectively. Of those reporting acute pain, 42% also experienced chronic pain. Factors that increased the odds of chronic pain were: predominately dyskinesia (odds ratio [OR]=3.52; 95% confidence interval [CI], 1.64-7.55); mixed spasticity-dyskinesia (OR=1.93; 95% CI, 1.07-3.47); bilateral involvement (OR=3.22; 95% CI, 1.844-5.61) and Gross Motor Function Classification System level IV (OR=2.32; 95% CI, 1.02-5.25), and V (OR=3.73; 95% CI, 1.70-8.20). Pain frequently interferes with sleep, attention, ability to have fun, and quality of life. Short-acting pharmacologic analgesics, thermotherapy, hydrotherapy, and massage were commonly used for pain management. CONCLUSIONS: Routine screening for pain is critical for early identification and intervention. Multimodal interventions are needed to address the biopsychosocial model of pain, and should be tailored for all abilities across the CP spectrum.