Development of the Relationships Among Dynamic Balance Control, Inter-limb Coordination, and Torso Coordination During Gait in Children Aged 3-10 Years

Abstract

Knowledge about the developmental process of dynamic balance control comprised of upper arms and upper legs coordination and trunk and pelvis twist coordination is important to advance effective balance assessment for abnormal development. However, the mechanisms of these coordination and stability control during gait in childhood are unknown.This study examined the development of dynamic postural stability, upper arm and upper leg coordination, and trunk and pelvic twist coordination during gait, and investigated the potential mechanisms integrating the central nervous system with inter-limb coordination and trunk and pelvic twist coordination to control extrapolated center of the body mass (XCOM). This study included 77 healthy children aged 3-10 years and 15 young adults. The child cohort was divided into four groups by age: 3-4, 5-6, 7-8, and 9-10 years. Participants walked barefoot at a self-selected walking speed along an 8 m walkway. A three-dimensional motion capture system was used for calculating the XCOM, the spatial margin of stability (MoS), and phase coupling movements of the upper arms, upper legs, trunk, and pelvic segments. MoS in the mediolateral axis was significantly higher in the young adults than in all children groups. Contralateral coordination (ipsilateral upper arm and contralateral upper leg combination) gradually changed to an in-phase pattern with increasing age until age 9 years. Significant correlations of XCOM_ML with contralateral coordination and with trunk and pelvic twist coordination (trunk/pelvis coordination) were found. Significant correlations between contralateral coordination and trunk/pelvis coordination were observed only in the 5-6 years and at 7-8 years groups.Dynamic postural stability during gait was not fully mature at age 10. XCOM control is associated with the development of contralateral coordination and trunk and pelvic twist coordination. The closer to in-phase pattern of contralateral upper limb coordination improved the XCOM fluctuations. Conversely, the out-of-phase pattern (about 90 degrees) of the trunk/pelvis coordination increased theXCOM fluctuation. Additionally, a different control strategy was used among children 3-8 years of age and individuals over 9 years of age, which suggests that 3-4-year-old children showed a disorderly coordination strategy between limb swing and torso movement, and in children 5-8 years of age, limb swing depended on trunk/pelvis coordination.

Keywords: balance control; dynamic postural stability; gait; inter-limb coordination; motor development; trunk coordination.

Figure 1

Experimental setup: The participants walk barefoot at a self-selected walking speed along an 8 m walkway. Twenty-seven reflective markers are attached to bony landmarks.

Figure 2

Typical samples of the angle-velocity phase plot in (A) ipsilateral upper arm and (B) contralateral upper leg and (C) the phase angle profile of these segments. Red markers and blue markers represent the first point and the last point during one gait cycle, respectively. Continuous relative phase (CRP) between these segments was calculated by subtracting the specific segment phase angle time series from each other.

Figure 3

Time profiles of the gait cycle for grand mean spatial margin of stability (MoS), extrapolated center of body mass (XCOM) displacements in the mediolateral axis, and kinematic joint movements with the standard deviation of each group. (A) Grand mean mediolateral margin of stability (MOS_ML) and (B) grand mean mediolateral XCOM displacements (XCOM_ML) and boundaries of base of support (BOS), which is defined by ankle marker on the stance side, and are represented by a thick line and thin line, respectively. (C) Grand mean trunk and pelvic rotational angular movements in the horizontal plane are represented by the gray line and the black line, respectively. (D) The grand mean of both the upper arm and upper leg joint angular movement in the sagittal plane is represented by the solid lines and the dotted lines, respectively. Ipsilateral and contralateral limbs are represented by the black lines and the gray lines, respectively.

Figure 4

(A) Mean relative phase of both upper arm combination, (B) both upper leg combination, (C) ipsilateral upper arm and leg combination, (D) contralateral upper arm and leg combination, and (E) trunk and pelvis combination for each group [± standard deviation (SD)]. *, Significant differences p < 0.05.

Figure 5

Mean margin of stability in mediolateral axis [MoS_ML; ± standard deviation (SD)]. *, Significant differences p < 0.05.

Figure 6

Results of regression analysis performed for age and extrapolated center of body mass in mediolateral axis (XCOM_ML). *,Significant correlation with age, p < 0.05.

Figure 7

Relationships between peak extrapolated center of body mass (XCOM) displacements in mediolateral axis (XCOM_ML) and (A) mean relative phase (MRP) of both arm combination, (B) MRP of both leg combination, (C) MRP of ipsilateral arm and leg combination, (D) MRP of contralateral arm and leg combination, and (E) MRP of trunk/pelvis combination. *,Significant correlation, p < 0.05.

Figure 8

Relationship between mean relative phase (MRP) of contralateral arm and leg combination and MRP of trunk/pelvis combination for each group. *,Significant correlation, p < 0.05.