Stunting delays maturation of triceps surae mechanical properties and motor performance in prepubertal children

Abstract

Malnutrition can lead to possible irreversible consequences in the development of muscle function and some of them are yet poorly characterized. The present study evaluated the mechanical properties of the triceps surae and motor performance in stunted (S) and eutrophic (E) prepubertal children (9 years ± 6 months). Height-for-age ratio was used as indicator of stunting due to early malnutrition, according to the World Health Organization. Torque was determined by maximal voluntary contractions (MVC) and musculotendinous (MT) stiffness was achieved through quick-release tests to obtain MT stiffness index (SI(MT)) and passive stiffness (K (p)) from linear MT stiffness-torque relationships. Percutaneous supramaximal electrically elicited contractions determined twitch torque (Pt) and electromechanical delay (EMD). Motor performance was evaluated by balance test. S group presented significantly lower MVC and a trend of lower Pt values indicating lower capacities to develop force under voluntary or induced conditions. Significantly higher SI(MT) and EMD values were observed, while K (p) and motor performance in balance were significantly lower. Higher SI(MT) values have been reported previously in youngest prepubertal children, indicating that immature activation capacities can mask MT stiffness assessment during voluntary contractions, taking into consideration the higher EMD values as a measure of muscle stiffness contribution. Lower K (p) may indicate a delay in the maturation of tendinous tissue in S group, influencing motor performance in balance. The present study shows that malnutrition leads to adaptation of intrinsic MT elastic properties, but depends on the level of the observed structure.

The mediation effect of anthropometry and physical fitness on the relationship between birthweight and basal metabolic rate in children

“…As the main predictor of BMR is the FFM, a lower lean tissue mass may be implicated within the reduction of BMR and in body fat accumulation 17 . It was demonstrated that early malnourished children (9 years ± 6 months) presented lower capacities to develop force under voluntary or induced conditions 18 . Lower BW is linked to reduced motor performance including muscle strength, muscle endurance and cardiorespiratory fitness in children and adolescents 19 .…”

Birthweight, body composition, and motor performance in 7‐ to 10‐year‐old children

“…9 Motor performance encompasses several physical fitness components (cardiorespiratory, muscle strength, muscle endurance, body composition, agility, and flexibility) and motor coordination (fine and gross coordination).…”

“…8 Motor performance involves the integration of the central nervous system and the skeletal-muscle system to arrange the action of muscles, joints, and limbs to develop adequate strength, speed, and resistance for an intended motor task. 9 Motor performance encompasses several physical fitness components (cardiorespiratory, muscle strength, muscle endurance, body composition, agility, and flexibility) and motor coordination (fine and gross coordination). 10 Motor performance and gross motor coordination seem to be directly associated with regular physical activity and body composition in children and adolescents.…”

“…12,13 Our previous study has shown that early malnourished (as indicated by current height/age ratio) children (9y [SD 6mo]) presented lower ability to develop strength under voluntary or induced conditions. 9 Lower birthweight was linked to reduced motor performance including muscle strength, muscle endurance, and cardiorespiratory endurance in children and adolescents. 14,15 Extremely low birthweight (<1500g) is considered a risk factor of motor impairment.…”

Influence of muscle activity on musculotendinous stiffness quantification in stunted, prepubertal children

“…Therefore, a nutritional related deficiency in tendon structure mineralization can hold for the lower passive stiffness in the children of the S group. Such adaptive responses suggest that the MT stiffness index evolution in stunted prepubertal children is delayed, being similar to younger eutrophic counterparts (Lambertz et al, 2003;Paiva et al, 2012).…”