Correlation between quadriceps activation and proprioception in patients with knee osteoarthritis

Objective: To investigate the correlation between the activation status of
quadriceps muscle and the proprioceptive accuracy in patients with knee
osteoarthritis (KOA). Methods: We included 43 outpatients diagnosed with
KOA and 45 health subjects from October 2024 to May 2025. The correlation
between the absolute error in knee Joint Position Reproduction (JPR) and
the root mean square (RMS) and median frequency (MDF) of quadriceps
surface electromyography during walking and stair climbing was analyzed.
Results: The JPR of 45° in KOA patient is significantly higher than health
subjects. There was no significant difference in 30° and 60° JRP between
the two groups. While walking, there is no significant difference of the
sEMG data in two group. While going up stair, the RMS of LVM and RVM in
KOA group had increased activation compared with the health subjects. In
KOA group, while going up stair, the JPR absolute error angle of 30° was
negatively correlated with the MDF of RVL, the JPR absolute error angle of
45° was positively correlated with the RMS of RVM, and the JPR absolute
error angle of 60° was positively correlated with RMS of LVM and RVM.
There are no significantly correlation in JPR absolute error angle and the
surface electromyography of the quadriceps muscle while walking and in
health control group. Partial correlation analysis was performed on the
aforementioned correlated indicators with gender included as a control
variable, and the results indicated that in women group, the JPR absolute
error angle of 60° was positively correlated with RMS of LVM and RVM. In
KOA group, the RMS of LVL, RVL and RVM in walking was positively
correlated with the RMS of LVL, RVL and RVM in going up and down stair,
and the MDF of LVL, RVL and RVM in walking was positively correlated with
the MDF of LVL, RVL and RVM in going up and down stair. In health control
group, the MDF of LVL, RVL and RVM in walking was positively correlated
with the MDF of LVL, RVL and RVM in going up and down stair. Conclusion:
This study indicated that during stair climb, KOA patients display a
unique pattern of elevated RMS of the VM. Notable relationships were
identified between the absolute error angles of JPR and sEMG parameters of
VM. The pronounced positive correlations in muscle activation patterns
between walking and stair upward and downward activities indicate a fixed,
task-invariant neuromuscular approach in KOA patients, possibly resulting
from compromised sensorimotor integration due to proprioceptive
impairments. These findings offer new insights into the pathogenesis of
KOA from a neuromuscular-sensory viewpoint, emphasizing the need
for future rehabilitation therapies to concurrently target proprioceptive
accuracy and the enhancement of muscle activation patterns.