Intramuscular aponeuroses and fiber bundle morphology of the five bellies of flexor digitorum superficialis: A three-dimensional modeling study.

Restoring balanced function of the five bellies of flexor digitorum superficialis (FDS) following injury requires knowledge of the muscle architecture and the arrangement of the contractile and connective tissue elements. No three-dimensional (3D) studies of FDS architecture were found in the literature. The purpose was to (1) digitize/model in 3D the contractile/connective tissue elements of FDS, (2) quantify/compare architectural parameters of the bellies and (3) assess functional implications. The fiber bundles (FBs)/aponeuroses of the bellies of FDS were dissected and digitized (MicroScribe® Digitizer) in 10 embalmed specimens. Data were used to construct 3D models of FDS to determine/compare the morphology of each digital belly and quantify architectural parameters to assess functional implications. FDS consists of five morphologically and architecturally distinct bellies, a proximal belly, and four digital bellies. FBs of each belly have unique attachment sites to one or more of the three aponeuroses (proximal/distal/median). The proximal belly is connected through the median aponeurosis to the bellies of the second and fifth digits. The third belly exhibited the longest mean FB length (72.84 ± 16.26 mm) and the proximal belly the shortest (30.49 ± 6.45 mm). The third belly also had the greatest mean physiological cross-sectional area, followed by proximal/second/fourth/fifth. Each belly was found to have distinct excursion and force-generating capabilities based on their 3D morphology and architectural parameters. Results of this study provide the basis for the development of in vivo ultrasound protocols to study activation patterns of FDS during functional activities in normal and pathologic states.

Physical Activity Promotion in Pediatric Congenital Heart Disease: Are We Running Late?

Low levels of habitual physical activity in children and adolescents with congenital heart disease (CHD) leads to various negative health outcomes, yet review of the literature indicates that many physicians, caregivers, and patients restrict physical activity owing to safety concerns. There is no evidence supporting absolute restriction of physical activity in pediatric patients with CHD; in fact, physically active lifestyles are as important for pediatric patients living with CHD as for the general population. To encourage long-term maintenance of physically active lifestyles, physical activity counselling and exercise prescription should be started early in childhood and be a core component of every patient encounter. Physical activity counselling should include clear messaging from physicians about recommended physical activities-not just restrictions-and a personalised written exercise prescription for the patient and family. Regular follow-up is essential to ensure adherence to recommendations, monitor patient responses to the increased physical activity level, and long-term surveillance. This review discusses the importance of a physically active lifestyle in children and adolescents with and without surgically repaired CHD and hypertrophic cardiomyopathy, excluding those with electrical abnormalities and channelopathies. It outlines gaps in knowledge regarding best practices for physical activity promotion in these patient populations, and provides recommendations on how to include physical activity promotion and exercise prescription in clinical practice based on existing literature. An important role for clinicians is identified, because the type of messaging they provide regarding physical activity will have a major impact on patients' and families' decisions to adopt an active lifestyle.