Workload and musculoskeletal problems: a comparison between welders and office clerks (with reference also to fishermen).

Previous studies have shown that subjective as well as clinical shoulder signs and symptoms are more common among welders than among office clerks. In the present study we wished to further evaluate the influence of different jobs on musculoskeletal problems, as well as the relationship between objective signs and subjective symptoms. This study confirmed that symptoms and signs from the shoulder were more common among the welders, who also had more subjective symptoms and clinical signs from other parts of the musculoskeletal system. Range of motion in different joint systems was, however, similar in the two groups except in external rotation of the shoulder, where welders had a more limited range. The degree of co-existence of subjective symptoms and clinical signs differed between different parts of the musculoskeletal system and was low particularly in the low back, hips, and ankles. This indicates low validity of many common clinical methods for determining musculoskeletal dysfunction. General health was good in both vocational groups and isometric strength for the welders was intermediate between that of office clerks (who had lower strength) and that of fishermen (who had higher strength, as disclosed in a previous investigation). To a similar degree welders and fishermen also had objective signs from most parts of the musculoskeletal system, whereas subjective symptoms from some parts of the body and medical consultations due to these problems were more common among welders. Atrophied shoulder muscles were more common among welders than among fishermen, whereas crepitations in the shoulder tended to be more common among the fishermen. This indicates that heavy dynamic work and prolonged static work may both induce shoulder injuries, but of different types.

The role of the anterior longitudinal ligament in Harrington rod fixation of unstable thoracolumbar spinal fractures.

This study was carried out to identify the role of the anterior longitudinal ligament in Harrington distraction rod fixation of the unstable spine, and to suggest clinical means of detecting a ruptured ligament when this is not obvious from a preoperative radiogram. In the unstable thoracolumbar spine, a marked difference in force is required for distraction and stabilization when the ligament is intact compared with when the ligament is disrupted. This can be detected by using a force-indicating distractor during the procedure. Furthermore, when the anterior longitudinal ligament is disrupted, the pattern of vertebral movements during distraction is altered. With the ligament intact, the vertebrae adjacent to the unstable segment will angulate around an axis situated ventral to the vertebral bodies, while the vertebrae will move apart in parallel planes when the ligament is severed. This can easily be detected by studying the movements of Kirschner wires inserted into the spinous processess.