Assessment of impulse duration thresholds for electrical stimulation of muscles (chronaxy) in dogs.
OBJECTIVE
To determine the electrical impulse duration thresholds (chronaxy) for maximal motor contraction of various muscles without stimulation of pain fibers in dogs.


METHODS
10 healthy adult Beagles.


METHODS
The dogs were used to assess the minimal intensity (rheobase) required to elicit motor contraction of 11 muscles (5 in the forelimb [supraspinatus, infraspinatus, deltoideus, lateral head of the triceps brachii, and extensor carpi radialis], 5 in the hind limb [gluteus medius, biceps femoris, semitendinosus, vastus lateralis, and tibialis cranialis], and the erector spinae). The rheobase was used to determine the chronaxy for each of the 11 muscles in the 10 dogs; chronaxy values were compared with those reported for the corresponding muscles in humans.


RESULTS
Compared with values in humans, chronaxy values for stimulation of AA motor fibers in the biceps femoris and semitendinosus muscles and muscles of the more distal portions of limbs were lower in dogs. For the other muscles evaluated, chronaxy values did not differ between dogs and humans.


CONCLUSIONS
Application of the dog-specific chronaxy values when performing electrical stimulation for strengthening muscles or providing pain relief is likely to minimize the pain perceived during treatment in dogs.
Sawaya
Serge G
SG
Unité Physiothérapie-Rééducation-Ostéopathie-USP 2007-03-135 RTI2B, Ecole Nationale Vétérinarire de Lyon, Université de Lyon, 69365 Lyon Cedex, Marcy l'Etoile, France.
Combet
Delphine
D
Chanoit
Guillaume
G
Thiebault
Jean-Jacques
JJ
Levine
David
D
Marcellin-Little
Denis J
DJ
D000818:Animals; D004285:Dogs; D004558:Electric Stimulation; D006801:Humans; D007700:Kinetics; D009119:Muscle Contraction / Q000502:physiology*; D018485:Muscle Fibers, Skeletal / Q000502:physiology; D018482:Muscle, Skeletal / Q000502:physiology*; D012684:Sensory Thresholds / Q000502:physiology; D013045:Species Specificity; D013997:Time Factors