Article Text

Download PDFPDF
Effects of light fingertip touch on postural responses in subjects with diabetic neuropathy
  1. R Dickstein1,
  2. R J Peterka2,
  3. F B Horak2
  1. 1Dept of Physical Therapy, Tel Aviv University, Tel Aviv, Israel
  2. 2Neurological Sciences Institute of Oregon Health & Science University, Portland, Oregon, USA
  1. Correspondence to:
 Dr F B Horak, PT Neurological Sciences Institute of Oregon Health & Science University, West Campus – Bldg 1, 505 NW 185th Avenue Beaverton, OR 97006-3499, USA; 


Objectives: To investigate the potential benefits from lightly touching an external supporting device on automatic postural responses to support surface translations, in subjects with profound sensory neuropathy in the feet due to diabetes mellitus (DM-PN).

Methods: Eight subjects with DM-PN and 10 age matched controls were tested under randomly ordered conditions of no fingertip touch (NT), light touch (LT; <1 N), and heavy touch (HT, as needed) of a stationary touch plate, during three backward translation velocities of the support surface at 10, 20, and 30 cm/s. Dependent variables included response latencies, CoP velocity, and the slope of the relation between centre of pressure (CoP) velocity and translation velocity as a measure of response scaling.

Results: Postural response latencies were significantly longer and scaling of initial response magnitude in proportion to translation velocity was significantly smaller in the DM-PN subjects compared to the control subjects. LT had no significant effect on response latencies of the DM-PN patients. Fingertip touch increased the slope of the scaling of postural response magnitude in both groups. However, DM-PN subjects had to use HT to improve response scaling, whereas control subjects improved scaling with LT as well as HT. LT significantly increased rightward CoP velocity towards the touch plate in all subjects.

Conclusions: LT did not reduce the latency or improve the scaling of automatic postural responses in subjects with peripheral neuropathy. The major effect of LT on the automatic postural responses of the DM-PN subjects was in increasing CoP velocity towards the side of the supporting device. HT in neuropathy subjects and LT in age matched control subjects increased the sensitivity of initial postural response scaling, suggesting that somatosensory substitution from a cane in the hand could be used to improve the magnitude of medium latency postural responses to slips and trips.

  • diabetes mellitus
  • posture, somatosensory, neuropathy
  • AP, anterior-posterior
  • CoP, centre of pressure
  • DM-PN, diabetes mellitus peripheral neuropathy
  • EMG, electromyography
  • HT, heavy touch
  • LT, light touch
  • MG, medial gastrocnemius
  • ML, medio-lateral
  • MP, metatarsal phalangeal
  • NT, no touch
  • VOR, vestibulo-ocular reflex

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.