Influence of the type of load on the cervical spine: a study on Congolese bearers.

Background Context: Cervical spine suffers degenerative changes with age and activity.
Purpose: The aim is to study the cervical spine of African head bearers by analyzing clinical changes and radiographic degenerative signs in comparison with a control group.
Study Design: Two groups of bearers, 28 bearers of heavy loads (50 to 60 kg) over short stretches and 33 bearers who carried bundles or lighter loads (30 to 35 kg) over long distances were clinically and radiographically examined and compared with a control group of 36 building industry workers who did not bear weights on their heads.
Methods: We noted the age, height, weight, body mass index (BMI), weight of load, years they had been working, width and length of the neck and any painful symptoms. We carried out a functional exploration of the cervical spine and a lateral radiograph of the cervical spine to assess degenerative changes and quantified the degenerative changes in the vertebral bodies and the discs. The angle of lordosis was measured.
Results: We found more prolapsed discs (p < .01) in the heavy-load bearing group than in the control group. The heavy-load bearers had larger neck width (p < .01) and more disc herniations (p < .05) than the bundler bearers. The frequency of prolapsed discs was higher at C5-C6 and C6-C7 levels. The listhesis was more frequent among bundle bearers than in heavy-load bearers and control group. A correlation between the number of disc herniations and age (p < .01) and years of work (p < .05) was observed. When all the bearers were compared with the control group, the differences found were the number of prolapsed discs, stiffness in the neck and reported pain (p < .01).
Conclusion: Load bearing on the head, particularly bearers of heavy loads, produced more radiographic degenerative signs, much stiffness in the neck and more reported pain than the control group.