this sounds like a question for a student on an exam......... i'm not doing your homework am i??


extensor tone..... okay... generally we're talking about knee extension and plantarflexion... so if the hemi-side is your stance leg, it's going to cause knee hyperextention, hip flexion, and lateral rotation of the pelvis toward the hemi-side... i don't think it's really these things that cause decreased sound-side step length...... i think it's the fact that the patient does not have the confidence in the hemi-leg to put enough weight on it, and therefore proper weight-bearing in stance on the hemi-leg does not occur-- THEREFORE the sound leg comes down too soon and you get a shorter step length...
what also happens is that the patient tends to have a decreased hip extension in terminal stance of the hemi-leg, and cannot then step long enough with the sound side...
but something that happens a LOT is the therapist puts a SOLID AFO (ankle foot othortic) on the hemi-leg..... this creates absolutely NO terminal stance and the patient is forced to move the weight over to the sound leg sooner because they can get NO dorsiflexion after "midstance" occurs...
make sure your patient has an articulating AFO--- or start him/her off with an ace wrap around the hemi-ankle...

was that a sufficient answer?? i'm not really sure if that's what you were going for....