On the left, RMS of the acceleration components at the three levels.

<p>On the right, attenuation coefficients from pelvis to head (C_PH), from pelvis to sternum (C_PS), and from sternum to head (C_SH) along the three anatomical axes. Parameters computed for the TD and CP groups are represented with empty and filled box-plots, respectively. Significant between-groups differences (p < 0.05 or p < 0.01) are reported with the symbol § or §§, respectively.</p

Sensor location and axes orientation of the Magneto-Inertial Measurement Units (MIMUs) attached on the children’s body segments.

<p>H: head level; S: sternum level; P: pelvis.</p

RMS_a inter-component relationships for the two groups (TD in light grey and CP in black).

<p>The inter-component comparison graphs characterized by significant different regression lines between the TD and CP groups are reported in figure: RMS_aAP vs RMS_aML for head (p = 0.007), RMS_aML vs RMSaCC for sternum (p = 0.048), and RMS_aAP vs RMSaCC for pelvis (p = 0.043).</p

Gait parameters obtained for both the TD and CP groups.

<p>Gait parameters obtained for both the TD and CP groups.</p

Functional abilities in the 3 PA intensity clusters.

<p>Vertical peak power during maximal counter-movement jump (CMJ) and sit to stand (STS) at maximal intensity in the high (HPAi; n: 19), medium (MPAi; n: 32) and low (LPAi; n: 21) PA intensity clusters. Data are expressed as means ± SD. *significantly different from MPAi.</p

Neural activation in the 3 PA intensity clusters.

<p>Percentage coactivation of the <i>biceps femoris</i> muscle during the knee extension maximal voluntary contraction (MVC) and of the <i>vastus lateralis</i> muscle during knee flexion MVC in the high (HPAi; n: 19), medium (MPAi; n: 32) and low (LPAi; n: 21) PA intensity clusters. Data are expressed as means ± SD. *significantly different from MPAi; ^†significantly different from HPAi.</p

Muscle strength in the 3 PA intensity clusters.

<p>(A) Peak torque and (B) rate of force development of the knee extensor and flexor muscles during maximal voluntary isometric contraction (MVC) in the high (HPAi; n: 19), medium (MPAi; n: 32) and low (LPAi; n: 21) PA intensity clusters. Data are expressed as means ± SD. *significantly different from MPAi.</p

Representative parameters of physiological factors underlying mobility for each age group.

<p>Values are means ± SD of the following mobility parameters: oxygen consumption (), heart rate (HR), and mechanical load at ventilatory threshold (T<i>vent</i>) during incremental cycling; vertical (V) and antero-posterior (AP) peak power during chair rising (STS) at maximal intensity; flight time and peak power during a countermovement jump (CMJ); peak torque and rate of force development (RFD) during isometric maximum voluntary contraction (MVC) of knee extensor muscles; muscle fiber conduction velocity (MFCV) of <i>vastus lateralis</i> and the antagonist coactivation from surface electromyography (sEMG) during knee extension maximal voluntary contraction.</p>*<p> = significantly different between young (Y) and older (O) participants;</p>†<p> = significantly different between middle-aged (M) and older participants;</p>‡<p>significantly different between young and middle-aged participants.</p