Difference in Isokinetic Strength of Shoulder Joint Muscles in Dominant versus Nondominant Upper Extremities in Children (original) (raw)
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Journal of research in medical sciences : the official journal of Isfahan University of Medical Sciences, 2011
Strength improvement of the shoulder muscles is a major goal in rehabilitation or athletic conditioning programs. The purpose of this study was to determine the effect of shoulder core exercises on the isometric torque of glenohumeral joint movements. A total of 36 healthy females with no history of shoulder injury enrolled in this study. Subjects were randomly assigned into the control group (n = 18, 22 ± 2.19 years of age) or experimental group (n = 18, 21 ± 2.05 years of age). Subjects in experimental group performed shoulder core exercises, using progressive resistance training, three times a week for six weeks. Subjects in control group performed no exercise. The isometric torque of shoulder movements were measured with Dynatorq device in isolated test positions of glenohumeral muscles at the beginning and after six weeks in both groups. shoulder core exercise training led to an increase in maximal isometric torques of shoulder scaption at 0° and 90° arm elevation, external and...
Physical Therapy in Sport, 2013
Objectives: To evaluate the external (ER) and internal rotator (IR) muscles' isokinetic peak torque and conventional and functional strength ratios in handball players and controls of different ages. Design: Cross-sectional and descriptive analysis. Setting: Exercise Physiology Laboratory. Participants: A total of 228 participants (108 athletes and 120 controls) were divided into five groups according to age, ranging from 13 to 36 years old. Main outcome measures: Isokinetic tests were performed concentrically at 60 and 300 deg s À1 and eccentrically at 300 deg s À1. Results: The differences between the athletes and controls regarding the peak torque of the ER and IR muscles were significant in males older than 18 years. The peak torque of the IR and ER muscles increased significantly across age in male athletes, but not in female athletes, except in the case of ER peak torque, which differed significantly between 13 and 16 years old. The female athletes presented higher conventional ratios (0.81 AE 0.07) than males (0.66 AE 0.08). Values represent means and standard deviations. Athletes and controls showed mean functional strength ratios below 1.0. Conclusions: Although there were no muscular ratio differences between the athletes and the controls, their ratio values were below the literature-recommended reference values to prevent shoulder injuries.
Background. Isokinetic strength imbalance is a risk factor for movement dysfunctions and injuries related to shoulder complex. The effects of recreational weightlifting on developing the imbalances between the shoulder muscles are not yet known. Objectives. To investigate the isokinetic concentric shoulder muscle strength values (peak torque normalized to body weight) in recreational weightlifters (RWL) and to compare the shoulder muscles agonist/antagonist ratios with nonweightlifters. Methods. Thirty male RWL with mean age, weight, height, and body mass index (BMI) of 21.56 years, 84.25 kg, 175.34 cm, and 26.51 kg/m 2 , respectively, matched with nonweightlifters served as a control group. The normalized concentric peak torque values of shoulder flexors, extensors, abductors, adductors, and internal and external rotators were measured at angular velocity 120°/sec by using Biodex isokinetic system. Moreover, the agonist/antagonist strength ratio for all muscle groups were calculated. Results. The normalized peak torques of RWL group were significantly greater than the control group (p < 0:05). The abductor/adductor and external rotator/internal rotator ratios of the RWL were significantly lower than the control group (p = 0:008 and 0.009, respectively). Conversely, there was no significant difference between both groups in relation to the flexor/extensor ratio (p = 0:259). Conclusion. These results suggested that the recreational weightlifting exercises place trainees at risk of muscle imbalances. Therefore, the restoration of a normal concentric abductor/adductor and external rotator/internal rotator strength ratios may decrease the risk of possible shoulder injury.
Test-retest reliability in isokinetic muscle strength measurements of the shoulder
Journal of Rehabilitation Medicine, 2002
Test-retest reliability is important for long-term follow-up; however, data on the reliability of isokinetic dynamometry of the shoulder are scarce. Twenty subjects (50% male) were measured; 10 with asymmetrical use of the arms (mean age 27 years) and 10 used their arms symmetrically (mean age 32 years). A Biodex 1 dynamometer (Multi joint system 2) was used. Abduction/adduction and external/internal rotation were measured following a standardized protocol. Performed scheme: two sessions with a 2-week interval, all measurements were done with 60°/second (5 repetitions) and respectively 120°/second and 180°/second (10 repetitions). Differences in the mean peak torques, split for muscle group and gender were signi cant. Intraclass correlation coefcients ranged from 0.69 to 0.92. This implies good to excellent reliability in research on groups. To determine testretest reliability of two consecutive individual measurements smallest detectable differences (SDD) were computed and ranged from 21% to 43%. It is questionable whether the SDDs are small enough to detect real changes in muscle strength.
Shoulder Isokinetic Performance in Healthy Professional Judo Athletes: Normative Data
Acta Ortopédica Brasileira, 2019
Objective: To evaluate normative data of shoulder isokinetic strength in healthy professional judo athletes. Methods: Cross-sectional study with 20 professional male and female athletes (10 female), evaluated with an isokinetic dynamometer. The strength assessment was carried out in external and internal rotation, flexion, extension, adduction and abduction. All data collected on muscle torque were normalized with body mass index. Results: Athletes demonstrated higher peak torque and joint work in shoulder adduction, abduction, flexion, and extension for the dominant limb compared to the non-dominant limb (p <0.05), with most of these deficits below 10%. Shoulder internal/external rotation ratios for male and female athletes had no significant differences between dominant and non-dominant sides, demonstrating values at 60°/s of 49.4 ± 7.2 on the dominant side of males and 49.1 ± 4.9 for females. Conclusion: The normative data are described to assist during treatment, return to sp...
Journal of Bodywork and Movement Therapies, 2010
The purpose of this study was to examine the relationship between hand-grip (HG) isometric strength and isokinetic moment of the shoulder musculature in 18 healthy male volunteers. HG isometric strength at 0 , 90 and 180 of shoulder flexion and isokinetic peak and average concentric moments of the shoulder rotators and abductors and the elbow flexors at 60 s À1 were measured on both the dominant and non-dominant sides. Pearson correlation coefficients revealed statistically significant positive relationships between HG isometric strength and isokinetic moments of the shoulder external rotators (rZ0.40e0.54), the shoulder abductors (rZ0.42e0.71) and the elbow flexors (rZ0.45e0.66) regardless of hand dominance. The positive relationships between HG isometric strength and isokinetic strength of the shoulder stabilisers was probably attributed to mechanisms providing stability to the elbow and shoulder joints either by force transmission via myotendinous and myofascial pathways or by ''overflow'' of muscular activity via neural circuits. The results of the present findings suggested that HG isometric strength can be used to monitor isokinetic strength of certain muscle groups contributing to the stability of the shoulder joint; however, HG strength may account only for approximately 16e50% of the variability in isokinetic strength of these muscle groups.
PeerJ, 2021
Background As participants who engage in CrossFit training and competition perform a large volume of high intensity overhead activities, injuries to the shoulder are one of the most common in this sport. Previous research in other sports has indicated that the isokinetic force power profile of the shoulder joint (IPSJ) rotator muscles may assist in the prediction of shoulder injury. Aim Therefore, the objective of this study was to determine the IPSJ in males engaged in CrossFit training at different competitive levels. Methods In a cross-sectional study design, participants (age, 24.1 ± 2.7 years) classified as ‘beginner’ (n = 6), ‘intermediate’ (n = 7) or ‘advanced’ (n = 9) provided informed consent to participate in this study. The IPSJ assessment involved rotational and diagonal movements, including internal and external shoulder rotator muscles, at both 180°.s−1 and 300°.s−1. The variables analysed were peak torque/body mass (%), mean power (W) and the external/internal peak to...
2018
Shoulder strength is essential for gymnasts in order to succeed in their sport, but little research has examined isometric and isokinetic shoulder moment and flexion/extension ratios. The purpose of this study was to evaluate the relative and absolute reliability of isometric and isokinetic shoulder moment and shoulder flexion/extension ratios. Fifteen international level male gymnasts (age: 19.3 ± 2.3 years) participated in the study. Two identical measurements with one week interval were applied using the isokinetic Humac Norm 770 dynamometer at three angles (45o, 90o, and 135o) for isometric and at three angular velocities (60o/s, 180o/s, and 300o/s) for concentric and eccentric action modes. All measurements were conducted in a range of motion of 10o to 180o, in supine position, bilaterally, with the elbows fully extended. Notwithstanding a small systematic bias (due to testing/learning) from measurement 1 to measurement 2 significant in four parameters, the results supported th...
Isokinetic Dynamometry in Measuring Bilateral Shoulder Peak Torque: Comparison and Prediction
An Najah University Journal For Research Humanities, 2010
Background: The shoulder joint is the main joint responsible for upper limb movements. Pathology of the shoulder joint creates an imbalance in its bilateral and unilateral movement, in addition to balance and coordination of other joints and movement of the upper limb. Conflicting facts exist in the literature about whether bilateral comparison of shoulder strength is possible and how the dominant and the non dominant shoulder muscle strength relate to each other. Objective: To investigate whether flexion/extension and horizontal abduction and horizontal adduction on the shoulder dominant side are significantly different from the non dominant side, and whether a bilateral comparison between muscle strength can be made. Methods: Concentric flexion/extension and horizontal abduction/horizontal adduction shoulder movements were measured in 23 health male participants using the ISOCOM® dynamometer. Performing five repetitions of each synergetic movement, peak torque values were used for data analysis using the ANOVA variance test along with correlations and linear regression. Results: There was no statistically significant difference between dominant and non dominant flexion, horizontal abduction and horizontal adduction (p< 0.05). Poor to excellent correlations were found between movements. A linear regression made ـــــــــــــ ـ ــــــ ـ ـــــــ "Isokinetic Dynamometry in Measuring Bilateral Shoulder ….." An-Najah Univ. J. of Res. (Humanities), Vol. 24(10), 2010 ـــــــــــــــــــــــــــــــــ ــــ ــــ ـــ ــــــــــ between the dominant and the non dominant shoulder movements resulted in equations which could predict a shoulder's movement strength from its contra lateral one. Conclusions: The study showed that bilateral comparison is possible and can be of help in shoulder pathology rehabilitation as it helps quantifying strength and weakness of the shoulder movements, and is able to predict recovery level and rehabilitation outcomes of the injured shoulder.
Applied Physiology, Nutrition, and Metabolism, 2009
Muscle strength and activation were compared in boys and men during maximal voluntary elbow flexion and extension contractions. Peak torque, peak rate of torque development (dτ/dτmax), rate of muscle activation, and electromechanical delay (EMD) were measured in 15 boys (aged 9.7 ± 1.6 years) and 16 men (aged 22.1 ± 2.8 years). During flexion, peak torque was significantly lower in boys than in men (19.5 ± 5.8 vs. 68.5 ± 11.0 Nm, respectively; p < 0.05), even when controlling for upper-arm cross-sectional area (CSA), and peak electromyography activity. Boys also exhibited a lower normalized dτ/dτmax (7.2 ± 1.7 vs. 9.5 ± 1.6 (Nm·s–1)·(Nm–1), respectively; p < 0.05) and a significantly longer EMD (75.5 ± 28.4 vs. 47.6 ± 17.5 ms, respectively). The pattern was similar for extension, except that group differences in peak torque were no longer significant when normalized for CSA. These results suggest that children may be less able to recruit or fully utilize their higher-threshold...