Isokinetics and Exercise Science - Volume 19, issue 4

Authors: Land, Helen | Gordon, Susan

Article Type: Research Article

Abstract: Purpose: To systematically review the literature regarding isokinetic testing to identify values for isokinetic shoulder strength and agonist/antagonist ratios in the general population which may be used as reference values when assessing, planning and implementing shoulder rehabilitation. Methods: Electronic databases were systematically searched and reference lists of all retrieved papers were hand searched and nine relevant studies were identified. Two independent reviewers assessed methodological quality and extracted data. …Results: Seven studies reported the effect of limb dominance on strength with four reporting no significant difference between the dominant and non-dominant limbs. The studies which compared muscle strength with gender concluded that men were significantly stronger than women at all speeds in all directions. Age was reported to have no significant effect on muscle strength. Four studies agreed that adduction and extension muscle strength were greater than other directions and flexion, abduction, internal rotation and external rotation were the next strongest in that order. Conclusions: Nine low and moderate quality research papers have attempted to establish isokinetic shoulder strength in a general population. Poor consistency with respect to sample sizes, randomization and selection of testing velocities and positions did not allow direct comparison of the results. Future research involving symptomatic subjects will need to be matched to a group of subjects from the general population of the same age, gender and physical profile with adequate sample sizes representative of the symptomatic population. Show more

Keywords: Isokinetic, shoulder strength, strength ratios

DOI: 10.3233/IES-2011-0427

Citation: Isokinetics and Exercise Science, vol. 19, no. 4, pp. 231-241, 2011

Authors: Coburn, Jared W. | Malek, Moh H. | Housh, Terry J. | Johnson, Glen O. | Beck, Travis W.

Article Type: Research Article

Abstract: Background and objective: The purpose of this study was to compare an accelerometer (ACC) and a piezoelectric contact sensor (PEC) for the measurement of mechanomyographic (MMG) signals during submaximal to maximal isometric muscle actions of the vastus medialis. Materials and methods: Following the determination of maximal isometric strength (MVC), eight subjects (20.4 ± 1.3 years) performed isometric muscle actions at 10 to 90% isometric MVC in random order. An ACC and PEC were used to …simultaneously record the MMG signal. Results: For the composite data, there were linear increases in normalized MMG amplitude for both the ACC (r^{2} = 0.930) and PEC (r^{2} = 0.875), with no difference in slope coefficients (p > 0.05). Similarly, there were linear increases in MMG mean power frequency (MPF) for the ACC (r^{2} = 0.957) and PEC (r^{2} = 0.982), with no difference in slope coefficients (p > 0.05). Analysis of individual subject data revealed there were no significant differences in slope coefficients between sensors for MMG amplitude or MPF for any subject with the exception of a significant difference (p < 0.05) for MMG MPF for one subject. In addition, there were no significant (p > 0.05) mean differences between the ACC and PEC for normalized MMG amplitude or MPF. Conclusion: These results indicated that the ACC and PEC provide comparable information regarding MMG amplitude and MPF vs. isometric torque relationships of the vastus medialis. Show more

Keywords: MMG amplitude, MMG mean power frequency, isometric leg extension torque

DOI: 10.3233/IES-2011-0419

Citation: Isokinetics and Exercise Science, vol. 19, no. 4, pp. 243-250, 2011

Authors: Anastasi, Sara M. | Hamzeh, Maher A.

Article Type: Research Article

Abstract: The aim of this study was to evaluate the effect of an eccentric hamstring specific training programme on the percentage of bilateral muscle strength imbalance and maximal vertical jump height. Twenty-four, injury free female rugby union players took part in this study. Participants were split into two groups; intervention group (Nordic Hamstring (NH) (n=13) and control group (n=11)). Both groups completed normal training; the NH group completed a concurrent NH programme for 10 weeks. Pre and …post-training concentric/concentric isokinetic testing of peak torque was performed for hamstrings of both legs at 60°/s. Vertical jump height was also assessed. In the NH group, there was a significant decrease in mean percentage bilateral hamstring strength imbalance (pre=10.39 ± 3.53, post=4.63 ± 2.81, p < 0.05). There was also a significant increase in vertical jump height for the NH group (pre=31.22 ± 4.8 cm, post=35.93 ± 4.5 cm, p < 0.05). The NH programme caused favourable adaptations to bilateral hamstring strength imbalance and dynamic lower body performance. A programme based on NH exercise is potentially an effective preventive and rehabilitation tool for hamstring injury. Show more

Keywords: Strengthening, Nordic Hamstring exercise, hamstring injury, injury prevention

Citation: Isokinetics and Exercise Science, vol. 19, no. 4, pp. 251-260, 2011

Authors: Secchi, Leonardo L. B. | Muratt, Mavi Diehl | Ciolac, Emmanuel G. | Greve, Júlia M. D.

Article Type: Research Article

Abstract: Objective: To compare knee extension-flexion isokinetic performance between elite swimmers of simultaneous (SS – butterfly and breaststroke) and alternated swimming (AS – front crawl and backstroke) styles. Method: Nineteen short distance elite swimmers (50 m, 100 m and 200 m events), divided into SS (n=7; 23.3 ± 5.6 years) and AS (n=12; 22.6 ± 1.4 years) were tested for knee extension-flexion isokinetic strength at 60°/s (4 repetitions) and endurance at 300°/s (30 repetitions). Results: There were …no significant differences between groups or legs for concentric knee extension and flexion variables. However, the agonist/antagonist (HQ) ratio was lower (p=0.032) in AS than SS group for both legs. Conclusion: These results indicate the need for training programs to improve strength balance between hamstrings and quadriceps muscles in short distance elite swimmers. Show more

Keywords: Isokinetic evaluation, knee, muscle strength, swimming

DOI: 10.3233/IES-2011-0422

Citation: Isokinetics and Exercise Science, vol. 19, no. 4, pp. 261-264, 2011

Authors: De, Sujaya | Sengupta, Piyali | Maity, Payel | Pal, Amitava | Dhara, Prakash C.

Article Type: Research Article

Abstract: This investigation was aimed to assess age and sex related variation in the index finger flexion and extension strength and its association with some anthropometric characteristics. A total of 400 subjects (200 male and 200 female), 18–60 years were selected at random and divided into three age groups: 18–34, 35–50 and 51–60 years. Strength was measured using a dedicated device. Results revealed that finger flexion and extension strength was significantly greater (p < 0.001) in men …than in women. Irrespective of gender the right hand was significantly stronger (p< 0.001) than that of left hand. A significant variation in finger extension strength with age was noted for both genders. Positive correlations between strength and some anthropometry were indicated only in case of male subjects. Show more

Keywords: Finger, strength, reference

DOI: 10.3233/IES-2011-0423

Citation: Isokinetics and Exercise Science, vol. 19, no. 4, pp. 265-272, 2011

Authors: Draper, Nick | Canalejo, Jorge Couceiro | Fryer, Simon | Dickson, Tabitha | Winter, David | Ellis, Greg | Hamlin, Mike | Shearman, Jerry | North, Chris

Article Type: Research Article

Abstract: Rock climbing is an increasingly popular adventure sport with a growing research base. To date the growth of research and reporting styles has been somewhat haphazard and as a consequence comparison between studies can be problematic. The aim of this paper was to make suggestions about a number of changes that could be made to improve the consistency in reporting between studies. Included with this paper are two new tables, one each for male and female …climbers. These provide comparative grading scales for use in reporting for future studies. These tables also provide a suggested framework for grouping climbers according to their ability. Using the tables researchers could group the climbers in their study by a category name (lower grade, intermediate, advanced, elite or higher elite climber) or by a number (level 1–5). In addition, the authors make recommendations about climber characteristics that could usefully be reported in future to assist comparison between studies. It would be helpful to readers if the self-reported, highest lead climbs (on-sight and redpoint) could be reported for a climbing group, along with the types of climbing regularly undertaken. Show more

Keywords: Rock climbing, grade tables, climbing grades, Ewbank scale, Yosemite decimal scale, sport climing

DOI: 10.3233/IES-2011-0424

Citation: Isokinetics and Exercise Science, vol. 19, no. 4, pp. 273-280, 2011

Authors: Bračič, Mitja | Hadžič, Vedran | Čoh, Milan | Derviševič, Edvin

Article Type: Research Article

Abstract: Background: Previous studies have investigated the role of hamstrings and quadriceps absolute and/or relative peak torque at high concentric velocities (240° and 300°/sec) and sprint performance but their findings were inconclusive. However, no study so far has investigated the relationship between time to peak torque (TPT) of hamstrings and quadriceps at high concentric velocity and sprint ability. This parameter may play and important role in sprinting, as it is one of the indicators of the explosive …muscular strength that is crucial for sprinting performance. Method: Thirty six healthy physical education students without previous injury voluntarily participated in investigation. The measurements of the sprint times at 5, 10 and 20 meters were carried out using an infrared photocell. Quadriceps and hamstrings strength was tested concentrically at 240°/sec using Biodex System 3 dynamometer. Linear regression was used to evaluate the influence of hamstrings and quadriceps relative strength and TPT on sprint times at 5, 10 and 20 meters. Results. Hamstrings' TPT significantly predicted the sprint times at 5, 10 and 20 meters (p values were 0.001, 0.004 and 0.008, respectively). At 5, 10 and 20 meters the model was significant (F =7.12, p<0.01; F=5.31, p< 0.05; F=4.07, p<0.05, respectively) while R square values were 0.31, 0.26, and 0.21, respectively. Subjects with hamstrings TPT below 200 ms had significantly shorter sprint times at all sprint distances in comparison with subjects whose hamstrings TPT was above 200 ms. Quadriceps' TPT was not correlated with sprint times. Conclusion: The ability of the hamstrings to produce torque quickly can significantly influence the sprint times at 20 m sprint. Most of this effect is seen in the initial acceleration phase (first 5 m) while later on (at 10 and 20 m) this influence slightly decreases but remains significant. It seems that not only the absolute amount of strength, but also the rate of strength development within the muscle can influence the sprint times. Show more

Keywords: Isokinetic muscle strength, concentric-eccentric actions

DOI: 10.3233/IES-2011-0426

Citation: Isokinetics and Exercise Science, vol. 19, no. 4, pp. 281-286, 2011

Authors: Monteiro, Luís Fernandes | Massuça, Luís Miguel | García, José García | Carratala, Vicent | Proença, Jorge

Article Type: Research Article

Abstract: The majority of explosive actions during the Judo fight occur when the athlete is trying to overcome his/her adversary via rapid execution(s) of (isolated or chained) technical manoeuvres. The aim of this study was to compare the results of two plyometric muscular action tests (i.e., Squat Jump – SJ, and Countermovement Jump – CMJ) between judo- and non-judo- athletes. The investigation involved a cross-sectional examination of 102 subjects (age, 21.9 ± 3.4 years) divided into 3 performance groups: a) …Senior top elite judo athletes (n=50), b) Junior elite judo athletes (n=26) and c) Adult non-judo athletes (n=26). Thirteen biomechanical variables (including jump height, velocity, power, force in SJ and CMJ; time to peak force, to peak power and between peaks) were examined. The dataset was analysed using a Univariate analysis of variance. No significant differences in anthropometric variables were observed between groups. However, significant differences were observed in: a) jump height and peak velocity (SJ, CMJ), b) peak power and peak force (SJ), and c) peak eccentric force, peak eccentric power and peak concentric power (CMJ). We conclude that: a) the center of mass displacement achieved in the CMJ is higher than in the SJ; b) the optimisation of coordination between the eccentric and concentric phases of muscle action is not the primary determinant of performance of Judo athletes; and c) the main pre-requisite for success in elite judo athletes is superior peak eccentric power. Show more

Keywords: Concentric, eccentric, force, judo, plyometric, power, velocity

DOI: 10.3233/IES-2011-0429

Citation: Isokinetics and Exercise Science, vol. 19, no. 4, pp. 287-293, 2011

Authors: Malicka, Iwona | Stefańska, Małgorzata | Rudziak, Marta | Jarmoluk, Paweł | Pawłowska, Katarzyna | Szczepańska-Gieracha, Joanna | Woźniewski, Marek

Article Type: Research Article

Abstract: The aim of this study was to examine the effect of Nordic walking on upper extremity strength and the level of lymphoedema in women following treatment for breast cancer (BC). A group of 38 women with treated BC were assigned to two groups: a study group of 23 women taking part in 8 weeks of Nordic walking and a control group of 15 women. Each participant was assessed for bilateral muscle strength using an upper limb push-pull attachment. …Circumference measurement served for determination of the volume of the lymphoedema. In women after the surgical procedure on the right side statistically significant changes in the strength of pushing motion of both the right and the left were observed. In women after the surgical procedure on the left side these values were statistically significant only for the left extremity. No significant changes were demonstrated for the treated side; we did not record either the occurrence or the intensification of lymphoedema in women after BC treatment. So, Nordic walking can be considered as safe form of rehabilitation for this group of patients. Show more

Keywords: Breast cancer, Nordic walking, isokinetic testing, closed kinetic chain, muscle strength, lymphedema

DOI: 10.3233/IES-2011-0430

Citation: Isokinetics and Exercise Science, vol. 19, no. 4, pp. 295-304, 2011

Authors: Koç, Hürmüz | Aycan, Kenan

Article Type: Research Article

Abstract: Objective: The purpose of this study was to examine hand grip strength in individuals with and without the palmaris longus (PL) muscle. Method: Sixty-eight participants from different sports volunteered to participate in this study. The mean age of participants with PL (PL+) or without (PL-) was almost identical, 21.9 ± 1.9 y and 21.7 ± 1.5 y, respectively. Length of dominant arm, width of elbow, wrist and hand grip strength of the subjects were measured using measuring tape …whereas a hand grip dynamometer was used to measure hand grip strength. Results: The wrist-width, forearm flexion position and the hand grip strength differed significantly between the groups (p < 0.05). Conclusion: This result indicates that the PL may enhance hand grip strength. Show more

Keywords: Palmaris longus muscles, hand grip strength

DOI: 10.3233/IES-2011-0431

Citation: Isokinetics and Exercise Science, vol. 19, no. 4, pp. 305-309, 2011