Allometric Scaling Of Isokinetic Peak Torque In Young Basketball Players

Introduction
Scaling of muscle strength for body size allows better comparisons of muscle strength between different subjects,
especially in children. However, the literature suggests that the value of the scaling factor (b) may be different among
ages (Jaric, 2002), although the theoretical value is 1. Results of previous researchers in adults reported b values of near
1 (Weir, 1999). The purpose of the present study was to examine the scaling exponent of an allometric model between
fat free mass (FFM) and isokinetic peak torque (PT) in young basketball players.

Methods
A hundred twenty volunteered young male basketball players, aged from 12 to 17 years old, performed isokinetic knee
extension tests at 300/sec, 600/sec and 1800/sec. Fat free mass was determined using standard skinfold measurements.
The following allometric equation was used to determine b:
ln PT=ln a + b ln FFM (1)

Results
The b values were 1.028, 1.085 and 1.139 for 300/sec, 600/sec and 1800/sec, respectively. An example of the relationship
between LnPT and LnFFM is presented in Figure 1.

Discussion/Conclusions
The present results partly confirm previous findings (Weir, 1999), that allometric modelling of the isokinetic peak
torque and FFM curves results in a b which is similar to the theoretical value of 1. The b value appeared to be
significant different among ages, which means that ratio scaling is not always the most appropriate when scaling
isokinetic peak torque data in developmental ages.

References
[1]. Jaric, S. (2002). Muscle strength testing. Use of normalization for body size. Sports Med, 32: 615-631.
[2]. Weir, J., Housh, T., Johnson, G., Housh, D., Ebersole, K. (1999). Allometric scaling of isometric peak torque: the
Nebraska wrestling study. Eur. J. Appl. Physiol, 80: 240-248.

NOTA: O texto com a iconografia está no anexo.

Arquivo