Neuromuscular efficiency of the quadriceps in women with and without patellofemoral

Abstract

Patellofemoral pain (PFP) may contribute
to less activation of the quadriceps muscle, favoring
joint overload and pain. Neuromuscular efficiency (NME)
is a variable that evaluates the relationship between
the amount of neural stimuli and the ability to generate
force of in a given muscle, with the most efficient being
the one that produces greater muscle force, with less
activation of muscle fibers. In this sense, this study aimed
to evaluate the strength and NME of knee extensors in
women with and without patellofemoral pain. A total
of 24 adult women, recruited via a questionnaire, aged
from 18 to 30 years, with and without patellofemoral pain,
participated in this study. Anamnesis, anterior knee pain
scale, and numerical visual scale were applied. Subsequently,
the knee extensor strength, with a hand-held dynamometer,
and the NME of vastus medialis (VM), vastus lateralis (VL),
and rectus femoris (RF) were assessed. For statistical
analysis, appropriate tests were adopted to compare
variables between groups and correlate them. In all
statistical tests, a α<0.05 was adopted. Results showed
that women with PFP had 61% lower NME in the VM
and 52% in the VL, compared to the group without pain.
No significant difference was found for knee extensor
strength between groups. We conclude that pain negatively
influences VM and VL recruitment but does not change
quadriceps ability to generate strength.