Effects of age and task difficulty on postural sway, variability and complexity

This study aimed to examine the effects of age and the task difficulty on postural sway, variability and complexity. The participants were 90 able-bodied individuals from children (n = 39; age: 5.89 ± 0.94 years), young adults (n = 30; age: 23.23 ± 1.61 years) and older adults (n = 21; age: 64.59 ± 5.24 years) that took part in different balance tasks that were had different levels of cognitive and physical challenges. The main dependent variables were postural sway area, postural variability and postural complexity. The participants stood on a standard force plate for 10 seconds in each task condition, and the centre of pressure displacement was collected at 100 sampling frequency. The results of this study showed that children and older adults, in the more difficult tasks, had greater sway area and complexity and less postural variability. In addition, there was a linear trend in the stability measures as the difficulty of the task was increased. In conclusion, special populations, such as children and older adults, were more sensitive to the balance changes and used active control mechanisms to minimise the risk of losing balance in more challenging conditions

Effects of a developmental task constraints intervention on kinematic synergies during two-hand catching in children with developmental delays

The aim of this study was to examine effects of a task intervention on kinematic synergies in catching. Participants were young children (5.58 ± 0.52 years) with the lowest scores on two-hand catching, according to assessments with the Test of Gross Motor Development-2 (TGMD-2) and were allocated into two groups. The constraints group took part in an 8-week intervention, whereas the control group experienced a typical physical education. Both groups were assessed with motor development and kinematic coordination measures with a catching task with a ball thrown from 2 m distance. Kinematic variables were recorded using a wireless motion capture system. A principal component analysis (PCA) was used to measure the kinematic synergies formed among active body parts. Two synergies that emerged in catching were mainly utilised for “reaching” and “catching” the ball. The control group tended to re-organise the majority of active body parts into two functional units in all phases, whereas the constraints group adapted their active parts into functional units according to the requirement of the novel movement in the transfer task. The findings of this study suggested that task constraints could facilitate object control by re-organisation of active body parts into functional synergies to achieve successful performance

Locomotion postural variability and coordination in boys with overweight

The purpose of this study was to examine the variability and coordination of postural adaptations in normal weight children and those with overweight in running and hopping. Fifty-six boys between 7-10 years were classified into groups as overweight (n=33) or normal-weight (n=23). They performed two trials of running and hopping over a 20-meter straight line distance. Accelerometers were attached on the trunk and head for collecting body movements in different directions from 15 strides. Postural variability and coordination were calculated by multiscale entropy and cross approximate entropy for the running and hopping trials, separately. Findings highlight overweight boys had significantly higher trunk-head coordination in mediolateral direction than normal-weight boys (0.72 vs. 0.68). The hopping movement pattern had highest variability (9.88 vs. 8.77) and trunk-head coordination (0.61 vs. 0.67) than running. Excess body mass demands additional postural adaptations to compensate for reducing the risk of losing balance laterally in boys with overweight

Effects of locomotion task constraints on running in boys with overweight/obesity: the mediating role of developmental delays

Background Childhood obesity adversely affects the musculoskeletal system and is accompanied with motor development delays. Movement interventions that change the body composition and movement patterns is suggested as an effective way to minimise the childhood obesity adverse effects. Research question Whether a locomotion task constraints intervention is effective to change body composition, motor performance and running efficiency in overweight/obese boys with different levels of motor development. Methods Forty young boys (age: 8.21 ± 1.01 years) whose body mass index (BMI) was above the 85th normative ranked score were divided into 4 independent groups according to their development and BMI: intervention-typical, intervention-delay, control-typical and control-delay. A 6-week task constraints intervention with an emphasis on improving locomotion skills such as fast walking, running, jumping, hopping, skipping and leaping were carried out in the intervention group. Results The pre and post-intervention difference score on the sample dependent variables showed decreases in body mass and BMI and improvements in agility, joint kinematics and running economy in the intervention-typical group relative to other groups. Significance The findings highlight that the boys with overweight/obesity and typical development can benefit more from a short-term developmentally-appropriate intervention to refine the running pattern and agility skill that was accompanied by positive changes in body composition