Chest Stiffness Research Articles

The Biomechanics of Lower Abdominal Steering-wheel Loading

Twenty-five fully anesthetized swine were tested for biomechanical responses to lower abdominal steering-wheel loading. Supine subjects were impacted with the lower rim of a segmented steering wheel in a ventrodorsad direction at approximately the L-4 level of the lumbar spine. Peak force ranged from 0.13 to 8.56 kN, peak stroke from 16.1 to 123.8 mm, and peak velocity from 1.7 to 12.4 m/s. Mechanical response is presented in terms of force-deflection cross plots of force-time and displacement-time histories. Overall stiffness, normalized for equal stress-equal velocity scaling using a standard human cadaver mass, was found to be rate dependent and corridors are suggested. These findings indicate that the stiffness of the lower abdomen is less than upper abdominal stiffness and significantly lower than chest stiffness, although lower abdominal stiffness in living subjects is still slightly higher than it is in the lower abdomen of human cadavers. The maximum viscous response (VCmax) was a strong predictor of injury risk for the entire data set.

Family studies in Bechterew's syndrome (ankylosing spondylitis). I. Prevalences of symptoms and signs in relatives of HLAB27 positive probands.

All available adult first-degree relatives of 66 patients with HLAB27 positive ankylosing spondylitis were examined clinically and radiographically and their white blood cells were HLA typed. Ten per cent of all relatives and 20% of HLAB27 positive relatives had Bechterew's syndrome. An additional 10% had minimal radiographical changes in the sacro-iliac joints, or peripheral arthropathy. Sixteen out of 19 persons who had minimal radiographical changes in the sacro-iliac joints were HLAB27 positive. Backache was common (25% or more) in any group of relatives, and did not discriminate well between relatives with or without Bechterew's syndrome. Spine or chest stiffness should prompt examination for Bechterew's syndrome, but is an inadequate diagnostic criterion for the syndrome. Typing for HLAB27 is probably the best prognostic test, although most HLAB27 positive persons did not exhibit any objective sign of disease. Repeated radiographical examination of HLAB27 negative persons should be avoided.

How does Bechterew's syndrome (ankylosing spondylitis) start? Interrelations between onset of symptoms.

Detailed medical histories were obtained from 122 consecutive patients with Bechterew's syndrome (ankylosing spondylitis) who had been hospitalized at Oslo Sanitetsforening Rheumatism Hospital. Frequencies of symptoms, age at onset of symptoms and their interrelationships are presented. Low back pain affected more patients than any other symptom and, generally speaking, it started earlier than any other individual symptom. However, any symptom could antedate low back pain. Symptoms preceding low back pain were most frequently reported at a young age, and most often affected the extremities. The presence of psoriasis was associated with an increased frequency of symptoms in the peripheral joints. Acute anterior uveitis and chest stiffness were more common in males than in females. The influence of the selection of patients on the results is discussed.