Hind limb weight-bearing
The weight bearing test is based on the animal’s tendency to avoid pain
by shifting its weight from the (right) hind limb with the painful,
MIA-injected knee to the contralateral (left) limb with the healthy
knee. Changes in weight distribution between the limbs were measured
with an incapacitance tester (Incapacitance Tester Librae - for Mice and
Rats, Ugo Basile, Milan, Italy). Rats were placed in an angled Plexiglas
chamber that allowed them to lean on their hind paws via two separate
force pads. Once the animal had settled, five measurements of the forces
exerted by the hind limbs (in grams) were recorded and the average value
was used in the analysis. The results were presented as a percentage of
the weight distributed on the ipsilateral hind paw, calculated according
to the following equation: [weight on the right hind paw/(weight on
the right hind paw + weight on the left hind paw)] × 100.