Obese Youth Demonstrate Altered Landing Knee Mechanics Unrelated to Lower-Extremity Peak Torque When Compared With Healthy Weight Youth

Abstract

Obese (OB) youth demonstrate altered knee mechanics and worse lower-extremity performance compared with healthy weight (HW) youth. Our objectives were to compare sagittal plane knee landing mechanics between OB and HW youth and to examine the associations of knee and hip extension peak torque with landing mechanics in OB youth. Twenty-four OB and 24 age- and sex-matched HW youth participated. Peak torque was measured and normalized to leg lean mass. Peak knee flexion angle and peak internal knee extension moment were measured during a single-leg hop landing. Paired t tests, Pearson correlation coefficients, and Bonferroni corrections were used. OB youth demonstrated worse performance and lower knee extension (OB: 12.76 [1.38], HW: 14.03 [2.08], P = .03) and hip extension (OB: 8.59 [3.13], HW: 11.10 [2.89], P = .005) peak torque. Furthermore, OB youth demonstrated lower peak knee flexion angles (OB: 48.89 [45.41 to 52.37], HW: 56.07 [52.59 to 59.55], P = .02) and knee extension moments (OB: −1.73 [−1.89 to −1.57], HW: −2.21 [−2.37 to −2.05], P = .0001) during landing compared with HW youth. Peak torque measures were not correlated with peak knee flexion angle nor internal knee extension moment during landing in either group (P > .01). OB youth demonstrated altered landing mechanics compared with HW youth. However, no associations among peak torque measurements and knee landing mechanics were present.

Biomechanical variations in children who are overweight and obese during high‐impact activities: A systematic review and meta‐analysis

“…Detailed description of study selection and reasons for exclusion can be found in Figure 1. Using the Joanna Briggs Institute tool, seven articles were categorized as "high quality," 17,[31][32][33][34][35][36] and two article were categorized as "low quality" 37,38 (Table 2). Eight of the nine studies were cross-sectional designs, 17,[31][32][33][34][35]37,38 and one article was a randomized control trial.…”

“…Using the Joanna Briggs Institute tool, seven articles were categorized as "high quality," 17,[31][32][33][34][35][36] and two article were categorized as "low quality" 37,38 (Table 2). Eight of the nine studies were cross-sectional designs, 17,[31][32][33][34][35]37,38 and one article was a randomized control trial. 36 Meta-analysis was performed for stance time (I 2 = 28%), hip flexion angle (I 2 = 0%), and knee flexion angle (I 2 = 0%) due to low statistical heterogeneity (Figure 2).…”

“…36 Meta-analysis was performed for stance time (I 2 = 28%), hip flexion angle (I 2 = 0%), and knee flexion angle (I 2 = 0%) due to low statistical heterogeneity (Figure 2). 29 Included studies in meta-analysis were 34,36,38 five analyzed OB, 17,31,32,35,37 and one analyzed OW/OB grouped together compared with HW. 33 OW and OB were defined differently depending on study design.…”

“…33 OW and OB were defined differently depending on study design. Seven studies classified participants using body mass index percentile (BMI%) according to age and sex (>85th to 94th percentile considered OW, >95th percentile considered OB), 17,[31][32][33][34][35][36] one study used child reference curves for body fat percentile, 38 and one study did not report criteria used. 37…”

“…While the included articles revealed inconsistent findings regarding peak knee flexion angles, meta-analysis revealed significant evidence that OW/OB land with decreased knee flexion during jumping and hopping (Figure 2, Table 3). 32,35 Meta-analysis was unable to be performed on knee extension moments secondary to high heterogeneity, and qualitative assessment revealed inconsistent evidence regarding differences in knee extension moment. 17,32,35 Based on qualitative synthesis, there is inconsistent evidence regarding differences in peak 3).…”