Meezan Hamzavi
Research Mentor(s): Riann Smith
Mentor Department: School of Kinesiology
Authors: Meezan Hamzavi, Alexa Johnson, Riann Palmieri-Smith
Session: Session 5 (2:00pm – 2:50pm)
Presentation Type: Poster 111
Abstract
Anterior cruciate ligament reconstruction (ACLR) patients experience reduced quadriceps
muscle quality. Neuromuscular electrical stimulation (NMES) helps improve muscle quality,
though the most effective intensity to use is not understood. The purpose of this project was to
determine if high intensity NMES can improve muscle quality.
Six participants were randomized into two groups, an active NMES or a placebo group.
Participants in both groups received 16 treatments starting ~2 weeks post-surgery. The active
group received NMES at an intensity that elicited a quadriceps contraction at 40% of their
non-ACL limb maximal strength, while the placebo group received NMES at 15%. Quadriceps
ultrasound measurements were taken prior to surgery and after the intervention. The change
from baseline values for quadriceps echo intensity (EI) (post-intervention minus pre-surgery)
were then calculated from US images to quantify muscle quality.
For the rectus femoris (RF) placebo group (change score = 8.3±1.3) and active group (change
score = 6.6±9.8) and vastus lateralis (VL) placebo group (change score = 11.5±8.8) and active
group (change score = 11.9±11.0), both groups had higher EI post-ACLR, suggesting an
expected lower muscle quality after ACLR. For the vastus medialis (VM), however, the placebo
group decreased their EI (change score = -2.0±8.9), while the active group increased EI
(change score = 7.9±4.4) from pre-surgery to post-ACLR. This could suggest a protective effect
of the placebo intervention. A larger sample size with a statistical comparison of the data is
needed to make conclusions.
