What governs the size of the retraction gap in divided peripheral nerves

The retraction gap in severed peripheral nerves form a part of the critical gap distance. It thus contributes to determining its size. The extent of retraction of severed nerves is variable and depends on joint movements. However, the individual distributions of the retraction gap are more or less constant and remain unaffected in various joint positions. The mean gap size is related to the level of nerve section and it becomes smaller as one moves distally. The degree of retraction increases in a wider, and decreases in a narrower section of the course of the nerves. In consequence of the existing attachments of each nerve to its bed there is inhibition of retraction, but much freer retraction is possible when these attachments are eliminated.