Tissue tightness disposes to disc hernia.

It seems likely that the tightness of tissue influences a patient's disposition to disc hernia. The aim of this study was to compare the mechanical behaviour of tissue from disc hernia patients with that of controls. A computerized finger hyperextensometer was constructed, which allowed the measurement of the viscoelastic properties of the capsule and ligaments at the metacarpophalangeal (MCP) joint. The disc group showed a reduced maximal extension angle of MCP joint II (P < 0.01), reduced tissue recovery value (P < 0.05), reduced relative subsecant area (P < 0.01) and relative integral of the regression curve (P < 0.01). The results indicate that an anulus fibrosus with reduced extension properties, reduced capacity of energy absorption and retarded shape recovery disposes to rupture.