Showing 5 results for Contraction
Zman T, Jalali Ma,
Volume 58, Issue 2 (5-2000)
Abstract
Metabolic alkalosis is characterized by high HCO3- as it is seen in chronic respiratory acidosis, but PH differentiates the two disorders. There is no characteristic symptom or sign. Orthostatic hypotension may be encountered. Weakness and hyporeflexia occur if serum K+ is markerdly low. Tetany and neuromuscular irritability occur rarely. We report the results of retrospective data analysis of metabolic alkalosis in 15463 patients hospitalized Pediatric Medical Center in Tehran during years 1995-1997. We found 50 cases of metabolic alkalosis (rate of 0.32 percent. 64 precent male and 36 percent female). Most of them had growth failure (40% were bellow 3 percentile of height by age, 44% bellow 5 percentile of weight by height). More than 60 percent had hypokalemia, hypocloremia and hyponatremia. The most common cause of Metabolic alkalosis was cystic fibrosis and pyloric stenosis. Fifty percent of cystic fibrosis patients and Bartter cases had metabolic alkalosis. Metabolic alkalosis should be considered in every pediatric patient presented with projectile vomitting.
Vasaghi Gharamaleki B, Keshavarz M, Gharibzadeh Sh, Marvi H, Mosayebnejad J, Ebrahimi Takamjani E,
Volume 66, Issue 6 (9-2008)
Abstract
Background: The typical features of eccentric exercise-induced muscle damage are delayed-onset muscle soreness (DOMS) and prolonged loss of muscle strength. It has been shown that passive warmth is effective in reducing muscle injury. Due to the interaction of different systems in vivo, we used isolated perfused medial gastrocnemius skeletal muscle to study the direct effect of temperature on the eccentric contraction-induced force loss.
Methods: After femoral artery cannulation of a rat, the left medial gastrocnemius muscle was separated and then the entire lower limb was transferred into a prewarmed (35oC) chamber. With the chamber temperature at 31, 35 and 39oC before and during eccentric contraction. Isometric force loss was measured after 15 eccentric contractions (N=7-9).
Results: Maximum contraction force reduction has been used as an index for eccentric contraction-induced force loss. In this study eccentric contraction caused a significant reduction in maximum isometric tension (p<0.01), but no significant difference was seen in isometric force loss at 31oC and 39oC compared with that at 35oC.
Conclusions: Our results suggest that temperature changes before or during eccentric contractions have no effect on eccentric contraction-induced force loss.
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.
Sadegh Norouzi , Fateme Esfandiarpour , Ali Shakouri Rad , Nasim Kiani Yousefzadeh , Zeinab Helalat , Reza Salehi , Mehrnoosh Amin , Farzam Farahmand ,
Volume 77, Issue 8 (11-2019)
Abstract
Background: The amount of anterior tibial translation during rehabilitation exercises is a key factor in organizing exercise regimen after anterior cruciate ligament injury. Excessive anterior tibial translation could increase the magnitude of tension imposed on injured and reconstructed anterior cruciate ligament knees. Forward lunge and open-kinetic knee extension exercises are commonly used in anterior cruciate ligament rehabilitation. However, there is insufficient data about the amount of anterior tibial translation in the eccentric and concentric phases of these exercises. This study compared the amount of anterior tibial translation in the eccentric and concentric phase of the lunge and seated knee extension in anterior cruciate ligament deficient and intact knees.
Methods: Using a non-probability sampling method, 14 men with unilateral anterior cruciate ligament rupture were selected for participation in this cross-sectional study. Participants were recruited from the university’s physiotherapy clinics. A uni-plane fluoroscope was used to image the knee joint while participants performed the forward lunge and open-kinetic knee extension exercises with the intact and injured legs in random order. Fluoroscopy imaging was performed in the radiology center at Sina Hospital, Tehran, Iran, from September 2013 to February 2014. Two factorial mixed ANOVA was used to analyze the data.
Results: There were no significant differences in the anterior tibial translation between the limbs and contraction phases during the lunge exercise. During open-kinetic knee extension, the anterior tibial translation in anterior cruciate ligament deficient knees was significantly more than that of healthy knees at 0⁰ (P=0.007). The anterior tibial translation in the eccentric phase of open-kinetic knee extension at flexion angles of 0⁰ (P=0.049) and 15⁰ (P=0.024) was significantly greater than that in the concentric phase.
Conclusion: In the lunge exercise, the amount of anterior tibial translation was similar between the eccentric and concentric phases and the intact and anterior cruciate ligament deficient knees, however, during open-kinetic knee extension exercise, in the eccentric phase was greater than that in concentric, and in the intact knees was greater than that in the intact knees, at 0-15⁰ angles.
Ezzatollah Rezaei, Mahmoud Reza Kalantari , Sahar Fereydouni, Kamrooz Pouryousef,
Volume 79, Issue 8 (11-2021)
Abstract
Background: Surgical margin determination in malignant lesions is essential and has a direct impact on the choice of postoperative treatments and patient follow-up. Therefore, the processes affecting this variable are worth exploring. This study aimed to evaluate the difference in surgical margin values in excisional skin samples during surgery and after formalin fixation.
Methods: A cross-sectional study was performed on forty randomly selected patients with benign and malignant skin lesions who were referred to the plastic surgery ward of Ghaem Hospital in Mashhad from November 2018 to January 2019. Malignant and benign skin lesions were excised with a healthy margin, then the specimens were sent to the pathologist in a formalin-containing container. The amount of tissue shrinkage and the factors affecting them were compared.
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Results: Among all 40 participants about 57.5% of the them were male and 42.5% were female. The mean age of the patients was 66.55±14.53 years. Surgical margin was evaluated in three patterns: before surgical incision and after surgical incision (P<0.001), before surgical incision and after formalin fixation (P<0.001), after surgical incision and after formalin fixation (P=0.02). In this study, the relationship between the age and initial length of the skin lesion with sample shrinkage was not statistically significant.
Conclusion: The results of this study showed that tissue shrinkage occurs both after incision and after formalin fixation. The highest rate of shrinkage was seen after surgical excision, which was due to the elasticity of the tissue itself. Increasing age and initial length of skin lesion did not affect this shrinkage. Also tumoral tissue contracted less than healthy tissue due to flexibility of fatty tissue and water and lipid content.
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