The effect of neural stretching technique on sympathetic outflow to the lower limbs

Slump stretching (a neural stretching technique) has been shown to be therapeutic in the management of grade one hamstring strains. To elucidate its physiological basis, this study was designed to examine the effect of slump stretch on sympathetic outflow to the lower limbs using telethermography. This study was conducted on 10 normal, elite track and field athletes. Temperature readings were taken using telethermographic imaging at four locations before and after stretching, on both stretched and unstretched lower limbs. Results indicated that a significant cutaneous vasodilator effect occurred in the stretched limb as evidenced by increased skin temperature, while the unstretched control limb showed a slight decrement in temperatures (p < 0.001). The findings indicate that slump stretch has a sympathetic inhibitory effect. This effect could be the underlying physiological mechanism for the therapeutic effect of slump stretch in grade one hamstring strains. This study demonstrates that physical maneuvers can produce neurogenic effects, which may account for their therapeutic value. J Orthop Sports Phys Ther 1992;16(6):269-274.