The relationship between muscle strength and physiological age: a cross-sectional study in boys aged from 11 to 15.
OBJECTIVE
To investigate the relationships between isokinetic knee flexor and extensor muscle strength and physiological and chronological age in young soccer players.


METHODS
Seventy-nine young, healthy, male soccer players (mean+/-standard deviation age: 12.78+/-2.88, range: 11 to 15) underwent a clinical examination (age, weight, height, body mass index and Tanner puberty stage) and an evaluation of bilateral knee flexor and extensor muscle strength on an isokinetic dynamometer. Participation in the study was voluntary.


RESULTS
The peak torque increased progressively (by 50%) between the ages of 11 and 15 and most significantly between 12 to 14. The knee flexor/extensor ratios only decreased significantly between 14 and 15 years of age. Puberty stage was the most important determinant of the peak torque level (ahead of chronological age, weight and height) for all angular velocities (p<0.0001). Muscle strength increased significantly between Tanner stages 1 and 5, with the greatest increase between stages 2 and 4.


CONCLUSIONS
The present study showed that isokinetic muscle strength increases most between 12 and 13 years of age and between Tanner stages 2 and 3. There was strong correlation between muscle strength and physiological age.
Degache
F
F
Service de médecine physique et de réadaptation, hôpital Bellevue, CHU de Saint-Etienne, 42055 Saint-Etienne cedex 2, France. francis.degache@chu-st-etienne.fr
Richard
R
R
Edouard
P
P
Oullion
R
R
Calmels
P
P
D000293:Adolescent; D000367:Age Factors; D002648:Child; D003430:Cross-Sectional Studies; D006801:Humans; D007866:Leg; D008297:Male; D053580:Muscle Strength