Article

This study's purpose was to determine if individuals who have had a
stroke primarily use sense of effort to gauge force production during static and
dynamic lower limb contractions. If relying on sense of effort while attempting
to generate equal limb forces, participants should produce equal percentages of
their maximum voluntary strength rather than equal absolute forces in their limbs. METHODS: Ten stroke participants performed isometric and isotonic lower
limb extensions on an exercise machine. RESULTS: When participants attempted to
produce equal bilateral isometric forces, there was a significant difference in
absolute force between limbs (ANOVA, P < .0001) but no significant difference
when force was normalized to each limb's maximum voluntary contraction (MVC)
force (P = .5129). During bilateral isotonic contractions, participants produced
less absolute force in their paretic limb (P = .0005) and less relative force in
their paretic limb (normalized to MVC force) when participants were given no
instructions on how to perform the extension (P = .0002). When participants were
instructed to produce equal forces, there was no significant difference between
relative forces in the 2 limbs
(P = .2111).
CONCLUSIONS: For both isometric and isotonic conditions hemiparetic participants relied primarily on sense of effort,
rather than proprioceptive feedback, for gauging lower limb force production.
This outcome indicates that sense of effort is the major factor determining force
production during movements. Lower limb rehabilitation therapies should not only
train strength in the paretic limb but should also train patients to recalibrate
force-scaling abilities to improve function.

Langue : ANGLAIS