Insole plantar pressure measurement during quiet stance post stroke.
PURPOSE
Reliable and clinically relevant measures of change in the postural control of people post stroke are important for evaluating clinical interventions. This study investigated the reliability and usefulness of the F-Scan insole plantar pressure system in measuring possible postural control variables in a sample of 15 people post stroke.


METHOD
A test-retest design was employed to measure contact pressure (CP), contact area (CA), center of force (COF) and its motion characteristics in four different stance positions. The data collection was repeated 30 minutes later to replicate the timing of a standard therapy period.


RESULTS
Good to excellent intertrial reliability was demonstrated (r = 0.704-0.986). The CP and CA data demonstrated relatively equal values between the hemi- and non-hemiparetic foot for the easier tasks (mean 3.6 to 3.7 KPa), and the asymmetry increased towards the non-hemiparetic foot as the tasks became harder (4 KPa vs. 3.3KPa on the hemiparetic). There were unexpected areas of high peak contact pressure on the more affected foot for several participants, whilst CA data quantified the expected redistribution of contact/weight toward the lateral border of the more affected foot in most, but not all, subjects. COF motion was markedly reduced on the more affected lower limb with a mean of 0.3 cm versus 0.5-3.8 cm for the other lower limb.


CONCLUSIONS
The main findings were that the F-Scan generates reliable data and produces variables that are clinically useful for measuring asymmetry parameters of postural control post stroke.