Effect of Surface Spinal Stimulation (SSS) on H-reflex in Normal Individuals

Electrical Stimulation is a technique that uses electrical currents to activate nerves innervating muscles and is primarily used to restore functions in people with disabilities. Surface Spinal Stimulation (SSS) is a form of electrical stimulation, and is used to influence the activity of nerve root fibers under the Para vertebral muscle through the surface electrodes applied over the skin of Para vertebral muscles (Wang et al, 2000). SSS is the process of stimulating the spinal cord with various electrical currents in order to produce stimulation and reduction in spasticity at the corresponding level of body segment. Spinal cord electrical stimulation is used in cerebral palsy and multiple sclerosis in reducing spasticity in the majority of subjects along with improvement in bladder function, respiratory function, volitional control; active and passive movement and mood state with carry over effects lasting from 30 minutes to 24 hours (Hazelwood et al, 1994). The H-reflex (Hoffmann reflex) is a reflectory reaction of muscles after electrical stimulation of sensory fibers (Ia afferents stemming from muscle spindles) in their innervating nerves (for example, those located behind the knee). The Hreflex test is performed using an electric stimulator, which gives usually a squarewave current of short duration and small amplitude (higher stimulations might involve alpha fibers, causing an F-wave, compromising the results), and an EMG set, to record the muscle response. That Abstract