Effects of Overweight and Obesity on Running Mechanics in Children

Bradley J Bowser; Kristen Roles

Disclosures

Med Sci Sports Exerc. 2021;53(10):2101-2110. 

In This Article

Results

Spatial–Temporal Variables

All participants ran between the given speeds of 3.3 and 3.68 m·s−1 (3.5% ± 5%) (OW/OB = 3.47 ± 0.04 m·s−1, HW = 3.49 ± 0.04 m·s−1, P = 0.23). However, the time spent in stance was 24% longer for the OW/OB group compared with the HW group (OW/OB = 0.37 ± 0.13 s, HW = 0.29 ± 0.10 s, P = 0.06). In addition, the OW/OB group displayed significantly shorter step lengths during running than the HW control group (OW/OB = 0.73% ± 0.07% body height, HW = 0.79% ± 0.07% body height, P = 0.009). Both differences were associated with a moderate effect (d = 0.73 and 0.72, respectively).

Joint Kinematics

Sagittal and frontal plane curves for the hip knee and ankle joint angles can be found in Figure 2. In the sagittal plane, the HW group displayed greater hip flexion angles at FS, VIP, and FZmax when compared with the OW/OB group (P ≤ 0.01, d ≥ 0.90) (Table 2). During early stance, hip extension excursion was significantly greater in the OW/OB group (P < 0.01, d = 1.36), whereas knee flexion excursion was significantly greater in the HW group (P ≤ 0.03, d ≥ 0.74) (Table 3). In the frontal plane, the OW/OB group displayed greater ankle eversion at FS and knee abduction at FS, VIP, and FZmax compared with the HW group (P ≤ 0.05, d ≥ 0.61) (Table 2). Compared with HW children, the OW/OB group displayed greater ankle eversion excursion and less knee and hip adduction excursions during the first part of the stance phase (P ≤ 0.04, d ≥ 0.69) (Table 3). Total ankle excursion in the frontal plane throughout stance was also significantly greater in the OW/OB group compared with the HW group (P = 0.007, d = 0.89) (Table 3). No other significant group differences were detected for the remaining joint kinematic variables of interest (P > 0.05).

Figure 2.

Joint angle curves of the ankle, knee, and hip in the sagittal and frontal planes during the stance phase of running.

Ground Reaction Forces

Results of the ground reaction force variables can be found in Table 4. FZmax was the only ground reaction force variable scaled to body weight that exhibited a significant group difference. Children classified as HW displayed significantly greater FZmax when compared with children classified as OW/OB (P = 0.004, d = 1.01). When the unscaled ground reaction force variables were compared across the two groups, the OW/OB group displayed significantly greater vertical and horizontal loading in all variables of interest (P ≤ 0.03, d ≥ 0.79).

Joint Kinetics

Results of the peak joint moments can be found in Table 5. Curves for the unscaled sagittal and frontal plane moments at the ankle, knee, and hip can be found in Figure 3. When moments are scaled to body mass and height, the results indicate that children who are classified as OW/OB display significantly greater peak knee adduction and hip abduction moments than HW children (P ≤ 0.05, d > 0.71). Peak hip extension moments scaled to body mass and height were significantly higher in the HW children (P = 0.03, d = 0.78). No other differences in peak moments scaled to body mass and height were detected.

Figure 3.

Unscaled joint moments of the ankle, knee, and hip in the sagittal and frontal planes during the stance phase of running.

Several differences were detected when the absolute values of the peak moments were compared across the HW and OW/OB groups of children. In the sagittal plane, children classified as OW/OB displayed significantly greater unscaled plantarflexion and dorsiflexion moments compared with HW children (P ≤ 0.01, d ≥ 0.79). Unscaled peak knee flexion and extension moments were also significantly greater in the OW/OB group (P ≤ 0.001, d ≥ 1.04). In the frontal plane, the OW/OB group displayed greater unscaled peak ankle inversion, knee abduction, and hip abduction moments compared with the HW group of children (P ≤ 0.05, d ≥ 0.60).

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