Isokinetics and Exercise Science - Volume 10, issue 3

Authors: Forthomme, B. | Croisier, J.L. | Foidart-Dessalle, M. | Crielaard, J.M.

Article Type: Research Article

Abstract: Article without abstract.

DOI: 10.3233/IES-2002-0099

Citation: Isokinetics and Exercise Science, vol. 10, no. 3, pp. 121-128, 2002

Authors: Cools, Ann M. | Witvrouw, Erik E. | Danneels, Lieven A. | Vanderstraeten, Guy G. | Cambier, Dirk C.

Article Type: Research Article

Abstract: The aim of this study is to determine the rest-retest reproducibility for measuring the peak torque and the total work of the protractors and retractors of the shoulder girdle according to the isokinetic concentric muscle action. The tests were performed in two sessions at a 7 day interval. Nineteen healthy volunteers were included. Evaluation was carried out with a Biodex® System 3 isokinetic dynamometer using the closed chain attachment. The protocol consisted of 5 isokinetic concentric …contractions at a linear velocity of 12.2 cm/sec and 10 repetitions at a velocity of 36.6~cm/sec. The shoulder girdle protraction and retraction movements were performed with the arm horizontal in the scapular plane, which is 30° anterior of the frontal plane. Intraclass-Correlation-Coefficients were calculated to establish day-to-day repeatability. Results show an excellent reproducibility for isokinetic peak torque at both velocities on the non dominant side (ICC 0.94--0.96) and very good to excel lent reproducibility on the dominant side (ICC 0.88--0.92). Reproducibility was also very good for total work values in both movement directions at both velocities (ICC 0.82--0.89). The results indicate that isokinetic protraction and retraction strength evaluation is a reliable tool in the evaluation of shoulder girdle muscular performance. This may be clinically important in the assessment of shoulder dysfunction. Show more

DOI: 10.3233/IES-2002-0093

Citation: Isokinetics and Exercise Science, vol. 10, no. 3, pp. 129-136, 2002

Authors: Bassa, Helen | Kotzamanidis, Christos | Siatras, Theophanis | Mameletzi, Dimitra | Skoufas, Dimitrios

Article Type: Research Article

Abstract: Determining the activation of antagonist muscles around the knee joint in athletic children can provide useful information for the better understanding of the mechanisms responsible for strength production in athletic populations during developmental ages. The purpose of the present study was to examine possible differences on a) concentric and eccentric isokinetic torque scores of knee muscles and b) electromyographic (EMG) activity of antagonist knee muscle groups during isokinetic concentric and eccentric knee extensions …and flexions between prepubertal gymnasts and non-athletic children. Ten gymnasts (age: 9.3 ± 0.8 yrs, training age: 3.4 ± 1.1 yrs, mass: 30 ± 3.6 kg, height: 132.1 ± 4.6 cm) and ten non-athletic boys (age: 9.1 ± 0.5 yrs, mass: 28.7 ± 3.4 kg, height: 131.4 ± 3.2 cm) performed maximal concentric and eccentric knee extensions and flexions on an isokinetic dynamometer at 45, 90 and 180°·s^{-1} randomly. The torque output of knee extensors and flexors and surface EMG act ivity of vastus lateralis (VL) and biceps femoris (BF) were recorded. The antagonist IEMG values were expressed as a percentage of IEMG of the same muscle when acting as agonist in the same muscle action and angular velocity. ANOVA designs indicated a significant effect of muscle action on the antagonistic IEMG of VL and BF (higher during concentric efforts). An effect of angular velocity was revealed on the antagonistic activity of BF and VL during concentric efforts for both groups. Additionally, no significant difference on the antagonistic activity of knee muscles was found between the two groups examined. The present results suggest that gymnastic training does not affect either torque production or antagonistic activity of knee muscles in boys aged 8--10 years. However, only a longitudinal study could determine possible differences on torque scores and antagonistic activity of knee muscles in gymnasts of various chr onological and training ages. Show more

Keywords: coactivation, knee muscles, isokinetic, gymnast, EMG, children

DOI: 10.3233/IES-2002-0094

Citation: Isokinetics and Exercise Science, vol. 10, no. 3, pp. 137-144, 2002

Authors: Ayalon, M. | Barak, Y. | Rubinstein, M.

Article Type: Research Article

Abstract: The purpose of this study was to analyze the isokinetic moment curve (IMC) of the knee extensors after ACL reconstruction using a qualitative approach. Fourteen professional soccer players after ACL reconstruction participated in this study. All subjects were free of any clinical symptoms related to the injury or surgery. The concentric strength of knee extensors was measured bilaterally using an isokinetic dynamometer. Each subject was tested twice, before and after 3 weeks of isokinetic training. For …each test, the IMCs of the knee extensors were analyzed by two examiners. The examiners were asked to differentiate between the involved and uninvolved side and classify the IMC of the involved side. The results indicate that a qualitative analysis of the shape of IMC is a valuable tool for patient evaluation and rehabilitation. Show more

Keywords: isokinetic, moment curve, shape, irregularity, consistency

DOI: 10.3233/IES-2002-0096

Citation: Isokinetics and Exercise Science, vol. 10, no. 3, pp. 145-151, 2002

Authors: Santos, R.S. | Pacheco, M.T.T. | Martins, R.A.B.L. | Villaverde, A.B. | Giana, H.E. | Baptista, F. | Zângaro, R.A.

Article Type: Research Article

Abstract: A decrease of the blood supply to the muscle can be significant to the development of muscular fatigue, an important factor of incapacity. In this study, the effect of L-arginine taken orally, on the physiologic process of the muscular fatigue in 12 healthy volunteers, was investigated through located exercise controlled by isokinetic dynamometer (Biodex Multi-Joint System 3 dynamometer). A protocol of the isokinetic concentric, continuous and reciprocal test was used for acquisition of the Work Fatigue …Indexes and it was accomplished the bilateral evaluation of the knee extension and flexion of the volunteers to an angular speed of 180°/s. The study was divided into two phases of test, Phase 1 being the control. At Phase 2, 3 g of arginine was given orally to each volunteer, daily for 15 days. The reliability and the estimate of the error in our measurements were analyzed, respectively, by Intra-class Correlation Coefficient (ICC) and Percent Standard Error of Measurement (SEM %) Reliable isokinetic measurements were obtained in the knee extension movement (ICC ≥ 0.80). Results demonstrated that for knee extension movement the mean values of Work Fatigue Indexes of Phases 1 and 2 are statistically different (p < 0.05). There was a significant decrease (mean 8.5%) indicate an improvement in the muscular resistance capacity to fatigue following the treatment by oral administration of arginine. Show more

Keywords: arginine supplementation, nitric oxide, muscle fatigue, isokinetic exercise

DOI: 10.3233/IES-2002-0096

Citation: Isokinetics and Exercise Science, vol. 10, no. 3, pp. 153-158, 2002

Authors: Carter, Rachel | Tarteval, Florence | Marks, Ray

Article Type: Research Article

Abstract: Background: In earlier work we noted that women with medial compartment knee osteoarthrosis and varus deformity displayed greater neuromuscular deficiencies of quadriceps muscles than those with normal tibial alignment when tested isokinetically at 90° sec^{-1} and at 0° sec^{-1} using an isokinetic dynamometer. Purpose: The present purpose was to provide further insight into the potential influence of muscular factors in the development of medial compartment knee osteoarthrosis. Methods: …Because our previous findings indicated significantly greater torque generating problems at higher isokinetic speeds than lower speeds among adults with varus alignment deformities, and prior work is strongly associated with isometric test outcomes, we elected to perform quantitative measures of maximal isometric knee torques generated 0° sec^{-1} and to compare these to validated goniometric alignment measures of the lower legs of 14 health individuals exhibiting genu varum on a single test occasion. Results. The analyses revealed: 1) a significant inverse relationship between the right quadriceps and hamstrings muscle torque and right tibia varus measures (r=-0.59; r=-0.66), and between the left hamstrings muscle torque and left tibia vara measures (r=-0.62) (p < 0.05) when controlling for gender; 2) antagonist-agonist knee torque ratios that tended to vary inversely with the magnitude of the prevailing varus deformity; 3) the presence of asymmetric tibia vara magnitudes with greater angulations recorded for the subject's right side, regardless of limb dominance; 4) greater varus angulation deformities for both legs of the males compared to the females (p < 0.05). Conclusions: The slope of the regression line linking the maximal knee extensor and flexor torques of healthy young adults tends to vary inversely with the degree of varus angulation as presently recorded. There may be considerable intra-individual and gender differences in the manifestation of this finding. These observations may have a bearing on the etiology and pathogenesis of uni- or bilateral medial compartmental knee joint disease in healthy adults exhibiting genu varum, hence warranting further study using more sophisticated measures and isokinetic testing at different angular velocities. Show more

Keywords: knee joint forces, quadriceps torque, hamstring torque, genu varum

DOI: 10.3233/IES-2002-0098

Citation: Isokinetics and Exercise Science, vol. 10, no. 3, pp. 159-165, 2002