[Source: Gait and Posture via Your Therapy Source]
Gait and Posture published some intriguing research on the effects of touch and trunk sway in a seated position.  There were 13 healthy, adult subjects who participated in the study.  Each participant performed a total of 12 trials of 60-seconds duration in a randomized order, combining the experimental conditions of no-touch, hand-touch (right index finger touching an object) or back-touch (maintaining an object touching the back at mid level T10) with no sensory perturbation, paraspinal muscle vibration or galvanic vestibular stimulation – GVS (sending of electrical messages to a nerve in the ear that controls balance). The results showed the following:

• touch through hand or back decreased trunk sway and decreased the effects of muscle vibration and GVS
• GVS led to a large increase in sway
• muscle vibration was only observed as an increase of drift and not of sway
• the stabilizing effect of touch was strong enough to mask any effects of perturbations of vestibular and paraspinal muscle spindle afference

Read the Rest of this Abstract on Your Therapy Source