scholarly journals Role of intra-abdominal pressure in the unloading and stabilization of the human spine during static lifting tasks

2005 ◽  
Vol 15 (8) ◽  
pp. 1265-1275 ◽  
Author(s):  
N. Arjmand ◽  
A. Shirazi-Adl
Author(s):  
Arun Kumar Gupta ◽  
Ekta Yadav ◽  
Nikhil Gupta ◽  
Raghav Yelamanchi ◽  
Lalit Kumar Bansal ◽  
...  

2000 ◽  
Vol 203 (11) ◽  
pp. 1679-1687 ◽  
Author(s):  
C.G. Farmer ◽  
D.R. Carrier

The pelvis of crocodilians is highly derived in that the pubic bones are isolated from the acetabulum and are attached to the ischia via moveable joints. We examined the possible role of this unusual morphology in lung ventilation by measuring ventilation, abdominal pressure and the electrical activity of several abdominal and pelvic muscles in the American alligator (Alligator mississippiensis). We found that the activity of two pelvic muscles, the ischiopubis and ischiotruncus muscles, was correlated with inspiration; these muscles rotate the pubes ventrally and thereby increase abdominal volume. During expiration, contraction of the rectus abdominis and transversus abdominis rotates the pubes dorsally. We suggest that this mechanism facilitates diaphragmatic breathing by creating space for caudal displacement of the viscera during inspiration. Because birds also use a dorso-ventral movement of the pelvis to effect ventilation, some form of pelvic aspiration may be plesiomorphic for archosaurs.


Author(s):  
M. El-Rich ◽  
A. Shirazi-Adl

The stability of the human spine in compression has attracted a considerable amount of attention in recent years. The passive ligamentous thoracolumbar and lumbar spines are known to exhibit large displacements or hypermobility (i.e., instability in an imperfect column) under compression loads <100N. Since such compression loads are only a small fraction of those supported by the spine even in regular daily activities, let aside the manual material handling tasks, the question arises as to how the spine is stablized in vivo? Various stabilizing mechanisms have been proposed and investigated; wrapping loading [Shirazi-Adl and Parnianpour, 2000], postural adaptations [Shirazi-Adl and parnianpor, 1999], intra-abdominal pressure [Cholewicki et al, 1999] and muscle activation/coactivation [Bergmark, 1989; Crisco and Panjabi, 1991]. In this work, a novel kinematics-based methad [Shirazi-Adl et al., 2002] is first applied to compute muscle forces and internal loads in standing postures under gravity with or without 200N loads held either on sides or close to the body in front. The stability of the system under given loads and prescribed postures is sudsequently examined using both linear bucking analysis based on the deformed configurations and nonlinear analysis while employing a liner stiffness-force relationship for muscules [Bergmark, 1989; Crico and Panjabi, 1991]. The relative accuracy of foregoing methods in stability analysis of some sample structures is also investigated. Moreover, the effect of co-activity on stability of the spine in neutral postures is studied.


1999 ◽  
Vol 49 (1) ◽  
pp. 84-91 ◽  
Author(s):  
Ursula B. Windberger ◽  
Roland Auer ◽  
Franz Keplinger ◽  
Friedrich Längle ◽  
Georg Heinze ◽  
...  

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
Francisco Javier Centellas Pérez ◽  
Agustin Ortega Cerrato ◽  
Juan Pérez Martínez ◽  
Francisco Llamas Fuentes

Abstract Background and Aims Genital edema is a frequent complication in those patients who are on peritoneal dialysis, generally secondary to the increase in intra-abdominal pressure that it entails. It occurs late after the implantation of the peritoneal catheter (after 30 days of implantation). The typical clinical manifestation of this condition is basically subcutaneous edema in the genital area, accompanied by pain and UF failure. The diagnosis must be made by using an imaging test, mainly CT-peritoneography. Method A series of clinical cases of PD patients who consulted for genital edema is reviewed, analyzing the role of peritoneography Results CASE 1 A 76-year-old male, 15 days after the start of the technique, consulted for right scrotal edema. It was decided to suspend CAPD and start hospital intermittent IPD with low volumes. A CT-peritoneography was requested, which revealed a right peritoneal-vaginal duct and a left inguino-scrotal leak. Surgical correction of the anatomical defect was performed without incident, with subsequent return of the patient to CAPD. CASE 2 A 78-year-old man, 15 days after the start of the technique, consulted for bilateral scrotal edema. A CT-peritoneography was performed, which showed that the leak of peritoneal fluid to the scrotum was due to bilateral inguinal hernia. Subsequently, inguinal hernioplasty of the surgical defect was performed without complications. Conclusion Genital edema, as a complication of patients with CAPD, appears in approximately 4-10% of them. CT-peritoneography is the diagnostic technique of choice. To do this, 150 ml of nonionic iodinated contrast, with a concentration of 300 mg/ml, are diluted in approximately 2 liters of dialysis solution, which are introduced into the peritoneal cavity of the patient 2 h before performing the CT. Subsequently, a CT scan of the abdomen and pelvis including the perineum is performed, in the supine position and craniocaudal direction.


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