I am not so sure its proprioception/sensory input - we have now done several post tib nerve block studies and ice studies (to numb plantar surface) and studies using 40grit sandpaper on top of orthoses (to increase sensory input) - in all studies alterations in sensory conditions/input did not alter the kinematic response to the foot orthoses ...... several studies by others have shown the importance of plantar sensation to balance and stability, which we are not investigating. We were concerned about, do you have to feel a foot orthoses (ie sensory input) to respond kinematically to it?
- the answer so far is NO
At the end of the day, we use foot orthoses to alter foot function to get symptomatic relief. We have measured a whole battery of kinematic, kinetic, EMG and pressure parameters/variables in several studies to see what ones foot orthoses do actually alter and MOST IMPORTANTLY
, which of the parameters/variables are related to a reduction in patient symptoms (plantar fasciitis and patellofemoral pain sydrome are the two populations we are using) - the main study (above) showed it wasn't reafoot motion changes that are related. We think we have narrowed it done to just one functional parameter (or maybe 3) that foot orthoses do alter that is related to symptomatic relief. We just not yet ready to 'sing and dance
' about it yet until we finish 2 RCT's next year testing it and look at the validity/reliability of clinical tests associated with it.... watch this space