Continuous, bilateral Achilles' tendon vibration is not detrimental to human walk

Sensory feedback from the moving limbs contributes to the regulation of ani mal and human locomotion. However, the question of the specific role of the various modalities is still open, Further, functional loss of leg afferent fibres due to peripheral neuropathy does not always lead to major alterati on in the gait pattern. In order to gain further insight on proprioceptive control of human gait, we applied vibratory tendon stimulation, known to re cruit spindle primary afferent fibres, to both triceps surae muscles during normal floor walk. This procedure would disturb organisation and execution of walking, especially if spindles fire continuously and subjects are blin dfolded. Vibration induced significant, though minor, changes in duration a nd length of stance and swing phase. and on speed of walking and kinematics of lower limb segments. No effect was induced on angular displacement of t he ankle joint or trunk and head kinematics, This paucity of effects was at variance with the perception of the subjects, who reported illusion of leg stiffness and gait imbalance, These findings would speak for a selective g ating of la input during locomotion and emphasise the notion that the centr al nervous system can cope with an unusual continuous input along the la fi bres from a key muscle like the soleus. (C) 2001 Elsevier Science Inc.