Experimental spondylosis in the rabbit spine. Overuse could accelerate the spondylosis.

It has been suggested that overuse can accelerate the progression of cervical spondylosis. This assumption was derived from a study examining premature onset of cervical spondylosis in patients with athetoid cerebral palsy. To clarify the relationship between overuse and structural abnormalities of the spine, repetitive extension-flexion movement was located onto young rabbit spines through electric stimulation of the trapezius muscle. Repetitive loads of 200,000 cycles caused more severe delamination of the anulus fibrosus than control at the lower cervical spine. In addition, it was associated with early osteophyte formation at the same disc level. No severe degeneration of the nucleus pulposus, however, occurred through repetitive loading. It was found that repetitive movement could accelerate the progression of structural abnormalities, such as cervical spondylosis. This result suggests that overuse is an important factor in the pathogenesis of spondylosis.