Abstract

Maximum voluntary strength per unit muscle area (absolute strength) related to age was investigated in normal 131 males and 127 females, 7 to 18 years of age. A Cybex machine was used to measure the isometric muscle strength in flexion and extension at elbow and knee joints, respectively. The cross-sectional muscle area of extensor and flexor at right upper arm and thigh were determined by using ultrasonic apparatus. The muscle area increased with age from 7 to 17 years in males and to 12 years in females. The absolute strength tended to increase with age from 7 to 12 years in males and 7 to 9 years in females. Observing from the view point of relative growth the absolute strength increased with the increment of body height up to 150-160 cm in males and 140-150 cm in females. Above these heights the absolute strength was independent of the height in both sexes. There were no differences in the absolute strength betweeen both sexes at a given age or body height. These results indicate that under 12 years (155 cm of height) for boys and 9 years (145 cm) for girls the increment in muscle area with age is not sufficiently accompanied by the development of muscle function. Verf.-Referat