Showing 6 results for Muscles
Gh.r Oliaei , M Akbari , H Bagheri , Mr Hadian , S Talebian, N Ahamad Vand ,
Volume 58, Issue 1 (4-2000)
Abstract
It is generally assumed that local muscular fatigue predisposes the individual to injury. Despite the significance of muscular fatigue and endurance, there are not much dynamic endurance studies for trunk muscles in the literature. Most of them have used isokinetic dynamometer which keeps the velocity of movement constant. In this studies with the help of an isoinertial dynamometer we have assessed the effect of repetitive and fatiguing flexion-extension movements patterns and motor output. 38 female subjects with no history of low-back pain for the 6 months volunteered for the study. A triaxial dynamometer was used that simultaneously provided measurement of torque, angular position, velocity impulse, work and power of each axis. Resistance were set independently for each axis by an interfaced computer. The subjects performed trunk flexion and extension movement against a saggital plane resistance equal to 50% of their maximum isometric extension strength in the upright position. The minimum resistance in the coronal and transverse planes were set-up at 5-7 Newton meters. The subjects were asked to perform trunk movement as quickly and as accurately as possible while exerting the maximum efforts until exhaustion. Immediately after dynamic test another isometric test was performed. A paired T-test procedure was performed among the selected parameters of the 1st middle and last 3 repetition cycles. The selected parameters are range of motion, velocity, torque, impulse, work, power, time interval and time of movement. Also, a paired T-test was performed between maximum isometric strength before and after dynamic test. All the selected parameters were significantly reduced in the saggital plane. Subjects displayed significantly less motor control and greater range of motion in the coronal and transverse planes in performing the primary task of flexion and extension. The reduction of the functional capacity of the primary muscles performing the required task is compensated by secondary muscle groups and the spinal structures is located in a more injury prone position, as identified by finite element models. In addition it is suggested that the fatigued muscles would be less able to compensate any perturbation in the load or position of the trunk. The repetitive loading results in a weakening of the viscoelastic passive elements of the spineless structure. The loss of ability to protect these weakened passive elements makes the spine susceptible to industrial and recreational injuries.
Talebian S, Bahrami Sh, Olyaei Gr, Bagheri H, Hadian Mr,
Volume 64, Issue 7 (8-2006)
Abstract
Background: The purpose of this study was to measure isokinetic maximum and average peak torque of internal and external rotators of glenohumeral joint in volley ball and tennis players
Methods: This study was performed on 17 professional female athletes
(7 tennis players &10 volleyball players) with age ranged 18-28 years. The subjects had played in a skilled team for more than 3 years. They were free from injury to their dominant shoulder in the past year. Subjects performed a five minute warm up by shoulder wheel and Maximum average Peak Torque (APT) were obtained unilaterally by a Biodex System 3 with the arm of players in 90 degree abduction at 120,180 & 210 o/s. Players performed five trails of concentric movements with 30 second rest between them.
Results: Maximum and average of maximum torques of shoulder rotator, in both groups, expect for internal rotators of tennis players, reduced by increase of movement speed (P<0.05). There are not significant difference between two groups in maximum, average of maximum torques and normalized data (ratio of maximum torque to weight). There is significant difference between two groups in percentage of APT of External rotator / Internal rotator ratio at 210 o/s (P<0.05).
Conclusion: Volleyball and tennis have no effect on isokinetic strength of shoulder rotators. In high speed, ratio of External rotator / Internal rotator is reduced. This indicates that increase in movement speed increase internal rotator in comparison to external rotator in these professional female athletes.
Tayebeh Mirhashemi , Mehri Ghasemi , Frideh Dehghan-Manshadi , Alireza Akbarzadeh-Baghban , Alimohammad Faizi , Alireza Sabbaghian ,
Volume 76, Issue 5 (8-2018)
Abstract
Background: Some studies show that frozen shoulder is due to the pathologic changes in the muscles around the shoulder. Measurement of the ultrasonic thickness of a muscle is a method for measuring the muscle changes. There is no study about the reliability of measurement of the muscle’s ultrasonic thickness around the shoulder in patients with frozen shoulder. The present study aims to investigate the intra-rater reliability of the ultrasonic thickness measurement of the supraspinatus, deltoid and upper trapezius muscles in women with frozen shoulder and healthy women.
Methods: This study was carried out during 4 months (June to October 2017). Twenty women consisted of 10 patients with frozen shoulder (mean age: 51.6±9.41 years) and 10 healthy subjects (mean age: 35.5±8.22 years) participated in this study. The patients from some clinics and hospitals in Tehran, and healthy subjects consisted of some personals and students in the School of Rehabilitation of Shahid Beheshti university of Medical Sciences participated in the present study. Measurements of ultrasonic thickness of the upper trapezius, supraspinatus and deltoid muscles in rest position carried out by the same rater two times in 48 hours. Ultrasonography instrument with linear probe (frequency: 7.5 MHz) were used for measurement of muscle thickness in millimeter.
Results: Reliability of the ultrasonic measurements of the muscle thickness in patients and healthy subjects was respectively as follow: The upper trapezius muscle (0.81, 0.81), the supraspinatus muscle (0.90, 0.92) and the middle deltoid muscle (0.93, 0.96). The reliability of the ultrasonic measurements of the muscle thickness for the upper trapezius muscle and the supraspinatus muscle was higher in healthy subjects compared to the patients with frozen shoulder. The reliability of the ultrasonic measurements of the middle deltoid thickness for the patients and healthy subjects was similar.
Conclusion: It seems that ultrasonography is a reliable method for measuring the thickness of the muscles around the shoulder in patients with frozen shoulder and healthy subjects.
Samane Khalkhali , Nahid Tahan , Alireza Akbarzadeh Baghban ,
Volume 76, Issue 8 (11-2018)
Abstract
Background: The transverse abdominis (TrA) muscle is one of the most important muscles that contribute to the stability of the lumbar spine. Strengthening of trunk muscles that have a significant role in trunk stability is very important in the field of professional sport, sport medicine and rehabilitation of patient with low back pain (LBP). Identifying the exercises that can improve the strength and endurance of these muscles in the efficient way is an important challenge in rehabilitation of LBP patients. The aim of this study was to investigate the effect of maximum voluntary isometric contraction of upper and lower limb muscles on ultrasonic thickness of the TrA muscle.
Methods: This is a pre-test post-test study. Thirty healthy young male subjects with mean age of 23 years were recruited from the university staff and student population (non probability sample). Ultrasonic thickness of the right and left TrA muscle (as an indirect measure of muscle activity) was taken at rest and during maximum isometric contraction of six muscle groups: shoulder and hip flexor, extensor and abductor muscles. Mixed-model ANOVA with repeated measures design were used to analyze data. To further analyses post hoc comparisons were performed with paired t-tests adjusted with the Bonferroni method. The significance level was set at P<0.05.
Results: The result showed that mean TrA thickness on right and left sides during maximum isometric contraction of the upper and lower limb muscles was significantly thicker than in resting position (P<0.001). The type of isometric contraction had a significant effect on the thickness of the TrA muscle on dominant side (P<0.05). As a result, the greatest change in the thickness of TrA muscle on dominant side was observed in hip isometric extension (P<0.05). There was a significant difference between the thickness of TrA during upper limb isometric contraction of dominant and non-dominant side (P<0.001).
Conclusion: Isometric contraction of upper and lower limb muscles especially in hip extension can increase the ultrasonic thickness of the transversus abdominis muscle.
Razieh Nazari , Mehri Ghasemi , Farideh Dehghan-Manshadi , Alireza Akbarzadeh-Baghban ,
Volume 77, Issue 8 (11-2019)
Abstract
Background: Rotator cuff injuries are the most common causes of shoulder pain and supraspinatus muscle is usually involved. Clinical tests are available and inexpensive tools for assessment of shoulder dysfunctions. The empty can (EC) and full can (FC) tests are considered as shoulder gold standard tests. Recently, hug up (HU) test has been developed to assess the supraspinatus. So far, no ultrasonographic study has compared supraspinatus muscle thickness in these testing positions. The present study aimed to compare the supraspinatus muscle thickness in the hug up testing position with the full can and empty can testing positions in young and healthy women.
Methods: Forty healthy women (mean age 21.62±2.4 years) participated in this cross-sectional-comparative study from April to June 2018 in the Biomechanic Laboratory of Rehabilitation School, Shahid Beheshti University of Medical Sciences in Tehran, Iran. The supraspinatus muscle thickness was scanned during rest and contracted states with a 0.5 Kg weight cuff. For contracted states, (A) EC testing position: the arm was at 90º abduction in the scaption plane with the thumb-down, (B) FC testing position: the arm was maintained at 90º abduction in the scaption plane with the thumb-up, (C) HU testing position: the palm of hand was placed on the opposite shoulder with the elbow flexed.
Results: The Bonferroni test showed significant differences (P<0.001) between the muscle thickness in the rest and the testing positions. The muscle thickness in the empty can testing position was significantly less than the full can testing position (P=0.001), no significant difference was found between the muscle thickness in the hug up testing position compared to the full can and empty can testing positions.
Conclusion: All of the empty can, full can and hug up testing positions demonstrated increased mean muscle thickness when compared to the rest position and the greatest muscle thickness was in the full can testing position. It seems that supraspinatus muscle thickness in hug up testing position is similar with empty can and full can testing positions.
Hamed Behrad, Mahdi Zareei , Zeinab Borjian Boroujeni , Seyed Saeed Asadi, Zeinab Tabanejad , Mohammad Panji, Masoud Asgharpour-Arshad ,
Volume 78, Issue 10 (1-2021)
Abstract
Life expectancy has increased throughout the world and, as a result, the population of the elderly is also rising. From the age of 30 years old, the human body mass loses about 0.1 to 0.5% of its skeletal muscle mass annually, which is accelerated after the age of 65 years old. Aging is characterized by a decrease in the progression of musculoskeletal and physical activity known as sarcopenia. Sarcopenia has a complex molecular pathogenesis that includes age-related changes in muscles’ neuromuscular activity, muscle protein replacement, the hormone levels and the related sensitivity of human body to these mentioned factors. The pathogenic conditions and other disorders in sarcopenia are the chronic inflammatory states that include oxidative stress and changes in behavioral factors, especially in nutritional status and physical activity. By definition of the European Working Group on Sarcopenia in Older People (EWGSOP), the diagnosis of sarcopenia is determined by the presence of two main factors which are low muscle mass and low muscle function. Besides, specific sarcopenia-related biomarkers have been identified for early diagnosis and accurate identification of the main pathophysiology mechanisms involved in the development of the disease. Since sarcopenia has adverse outcomes on public health in terms of behavioral factors, frailty, hospitalization and mortality of people, it is an important necessity for the social health system to plan some therapeutic approaches to prevention. The main and more important of these therapeutic approaches have known as exercises, nutritional supplements and hormonal therapies. Also, other new therapeutic strategies are under investigation to be introduced in the future. However, currently, it has been shown that only physical exercise has a positive effect on the controlling and prevention of sarcopenia and its adverse effects on human and public health. However, the role of appropriate nutrition is also effective. Therefore, carefully designed studies in terms of better utilization of physical activity are needed to achieve useful therapeutic results for sarcopenia management. Thus, this survey aims to review the other considerable studies on the pathogenesis, appropriate evaluation of the disease and treatment options for sarcopenia.
