Gy. Diaz et al., ELECTROMYOGRAPHIC ANALYSIS OF SELECTED LOWER-EXTREMITY MUSCULATURE INNORMAL SUBJECTS DURING AMBULATION WITH AND WITHOUT A PROTONICS(TM) KNEE BRACE, The Journal of orthopaedic and sports physical therapy, 26(6), 1997, pp. 292-298
Often, braces are an integral part of treatment programs for patients
with pathology of the knee joint, little evidence exists, however, as
to the effect of braces on muscle function. The purpose of this invest
igation was to compare electromyography (EMG) from six lower extremity
muscles during level walking without the Protonics(TM) knee brace and
with the brace at eight resistance settings. Surface electrodes were
placed on one lower extremity of 19 subjects (ages = 21-57) to evaluat
e EMG activity during ambulation with and without the knee brace. Data
were normalized to maximum voluntary contractions and averaged across
cycles. There was a significant increase in muscle activity of the re
ctus femoris, vastus medialis, and vastus lateralis muscles when the b
race resisted knee extension and was set at the level of 9. Significan
tly higher EMG levels also occurred in the vastus lateralis and vastus
medialis with the extension module set at level 6 when compared with
the no brace trial and resistance levels set at 6 and 2 with the flexi
on module. in this normal population, there was an increase in activit
y of selected muscles when the brace was set al the highest resistance
settings. These data serve as a guide for clinicians when considering
incorporation of a brace of this type into patient management.