Research Article

Criterion-Related Validity of a Simple Muscle Strength Test to Assess Whole Body Muscle Strength in Chinese Children Aged 10 to 12 Years

Table 1

Indicators and test methods of the SMST.

Test siteIndicatorsTest methodsInstruments

Upper limbsHand-grip (kg) [29]The participant stood, relaxed, with his/her arms naturally drooped to the sides of the body, palms inward, the hand to be tested holding the grip dynamometer, holding the strength measuring site, reaching slightly out. The range did not exceed 30°. When the participant was ready, he/she was required to use their maximum strength to grip the grip dynamometer once and read the record. Left and right hands were measured alternately.The Hui Hai student physical quality evaluation system (Hui Hai Electronics, Shanghai, China)
Knee bent push-up (times) [30]The participant began prone on the mat, with ten fingers forward and shoulder-width apart, on the ground. The arms were straight and the knees were on the mat. The feet were off the ground and overlapped each other and maintained a straight line from the head and the back to the knee. After hearing the signal, the participant flexed his/her arms to about 90° before pushing the body up and straightening his/her arms. This was counted as a push-up. Throughout the test, the participant held a straight line from the head and back to the knee, and there was no obvious pause between the movements of kneeing push-up. It took 1 minute to complete the knee bent push-up.The Hui Hai student physical quality evaluation system (Hui Hai Electronics, Shanghai, China)

TrunkBack muscle strength (kg) [30]The participants stood and adjusted the handle height of the back dynamometer to make the upper limb of the participant lean forward at 30°. During the test, the participants had both hands clenched on the handle and kept their legs straight, using the maximum strength of the arm, pulling up the back dynamometer. After pulling up the back dynamometer, the participants could not bend their arms or knees, or fall backwards.BCS-400 electronic back dynamometer (Hengqi Weighing Factory, Nantong, Jiangsu, China)
Sit-up (times) [29]The participant lied on his/her back on the mat with knees bent, with his/her fingers grasping the head (back of the head) in the ready posture. When the time started, the participant sat up as quickly as possible, with two elbows touching the outer sides of the two legs. Both shoulders, back, and head must be clenched to the mat in the ready posture. It took 1-minute to complete the sit-up.The Hui Hai student physical quality evaluation system (Hui Hai Electronics, Shanghai, China)

Lower limbsStanding long jump (m) [29]The participant stood behind the jump line, with feet naturally apart. The toes should not step on the line (preferably using a rope as the jump line). Both feet jump simultaneously from the standing point; taking a step or successive jumping was not allowed. The vertical distance from the trailing edge of jump line to the nearest landing point was measured.The Hui Hai student physical quality evaluation system (Hui Hai Electronics, Shanghai, China)
Leg muscle strength (kg) [29]The leg muscle strength test also uses the back dynamometer, but the test method is different. The participant handle height of the back dynamometer was adjusted to make the participant bend the knee at ~115°–125°. During the test, the participants had both hands clenched on the handle, holding the upper body upright and using their maximum strength of the arm to pull the back dynamometer. When pulling up the back dynamometer, the participants could not bend their arms, bend their body, or fall backwards.BCS-400 electronic back dynamometer (Hengqi Weighing Factory, Nantong, Jiangsu, China)