Revista Brasileira de Medicina do Esporte
Print version ISSN 1517-8692
SONZA, Anelise and ANDRADE, Mário Cesar de. Analysis of the isokinetic torque curves in shoulder movements . Rev Bras Med Esporte [online]. 2012, vol.18, n.2, pp. 91-94. ISSN 1517-8692. http://dx.doi.org/10.1590/S1517-86922012000200005.
The torque curve of an isokinetic evaluation provides indication about muscular performance and possibly deficit in the evaluated subject. However, automatic reports supplied by isokinetic systems may produce equivocated data and interpretations errors. Thus, the purpose of this study was to analyze the isokinetic torque curve, identifying at which point of the curve speed becomes constant according to the performed test. Moreover, it assesses if the maximum peak torque (MPT) is within the protocol stabilization. Swimming athletes (n=10) were evaluated at the isokinetic dynamometer Kin-Com® 125 AP. The athlete was requested to perform the maximum concentric (CC) - eccentric (EE) contraction in the movements of internal (IR) - external rotation (ER), flexion (FL) - extension (EX) and horizontal abduction (AB) - adduction (AD) of shoulder, 120°/sec and supine position. The Matlab 6.0 and Origin 6.0 software was used to process the curves. In the IR-ER movements in CC-EE contractions, considered more stable and with a lower lever arm, the speed remained constant in the range of 5 to 98% of the curves; while in the FL-EX and horizontal AB-AD, considered more unstable and with higher lever arms, 10 to 98% of the curves were observed. The movements of concentric IR and EX and concentric-eccentric FL and horizontal AB-AD, the PTM was concentrated in the first third of the isokinetic curve, which requires attention in the processing of the torque values. In the FL-EE, 80% of the PTM values were outside of the pre-set speed, requiring reprocessing, which would not occur in the reports automatically supplied. We suggest the disposal of the 5% initial and final torque curves for shoulder rotation movements and 10% for FL-EX and horizontal AB-AD in order to obtain more reliable interpretations of peak torque and acquisition of the true muscle condition.
Keywords : torque; shoulder joint; data analysis; muscle contraction; biomechanics.