TABLE 4

Mean (SE) and Median Force Exerted in the Knee Extension and Grip Tests,a by Gender and Age, United States, 2012

Knee Extension (lb)Knee Extension (kg)Grip (lb)Grip (kg)
nMean (SE)MedianMean (SE)MediannMean (SE)MedianMean (SE)Median
Boys
 66725.7 (2.7)25.911.7 (1.2)11.86949.4 (1.1)48.522.4 (0.5)22.0
 76134.3 (2.0)35.015.5 (0.9)15.96258.1 (2.2)b55.926.3 (1.0)25.4
 85339.6 (2.7)41.317.9 (1.2)18.75565.0 (1.4)65.529.5 (0.6)29.7
 95345.0 (4.6)45.320.4 (2.1)20.55575.0 (2.0)73.334.0 (0.9)33.3
 105951.5 (4.5)52.223.4 (2.1)23.75783.7 (1.9)b83.338.0 (0.9)37.8
 115469.6 (4.7)b69.631.6 (2.1)31.655100.4 (3.7)95.245.5 (1.7)43.2
 126473.4 (4.3)70.633.3 (1.9)32.064113.9 (2.2)107.651.7 (1.0)48.8
 136283.5 (5.7)84.437.9 (2.6)38.362133.0 (4.9)b132.260.3 (2.2)59.9
 145790.2 (8.2)85.940.9 (3.7)39.058153.5 (3.3)b150.369.6 (1.5)68.2
 156099.7 (10.7)b104.545.2 (4.8)47.460175.6 (4.4)b178.479.7 (2.0)80.9
Girls
 65529.4 (2.7)30.013.3 (1.2)13.65647.7 (1.5)47.821.6 (0.7)21.7
 76336.9 (3.0)37.616.7 (1.3)17.16351.8 (1.3)51.223.5 (0.6)23.2
 87043.3 (3.8)43.619.6 (1.7)19.87061.7 (1.5)60.628.0 (0.7)27.5
 95146.5 (4.2)45.521.1 (1.9)20.65069.5 (2.7)66.731.5 (1.2)30.3
 106548.3 (5.4)50.221.9 (2.4)22.86576.7 (2.5)71.834.8 (1.1)32.6
 116358.9 (4.3)57.826.7 (2.0)26.26492.4 (2.0)89.341.9 (0.9)40.5
 125869.0 (5.4)73.831.3 (2.4)33.558109.2 (3.6)106.549.5 (1.6)48.3
 136579.9 (7.2)80.536.2 (3.2)36.564116.9 (3.9)112.853.0 (1.8)51.2
 146881.7 (5.8)87.437.1 (2.6)39.668117.8 (1.9)114.753.4 (0.9)52.0
 154276.7 (8.1)82.334.8 (3.7)37.343121.2 (2.9)118.355.0 (1.3)53.7
  • Source: CDC/NCHS, NHANES National Youth Fitness Survey.

  • a Significant linear trends by age (P ≤ .001) for both gender-specific measures.

  • b Significant difference compared with girls (P < .05).