TOPLINE

In patients who underwent anterior cruciate ligament (ACL) reconstruction, neuromuscular activity remained altered in both the operated and non-operated limbs across the first postoperative year, joint position sense errors were smaller than in healthy individuals, and cortical activity showed no clear differences.

METHODOLOGY

• Researchers conducted a prospective observational study to examine neuromuscular and cortical activity over 1 year following ACL reconstruction.
• They included 31 patients who underwent ACL reconstruction (mean age, 25.6 years; 38.7% women) and were tested at multiple timepoints across the 12-month period. Patients were compared with 31 matched healthy control individuals who were tested once.
• Joint position sense (JPS) was assessed using simultaneous electroencephalography (EEG) to record electrical activity of the brain and electromyography (EMG) to record the electrical activity of muscles.
• EMG was recorded during stair descent at multiple timepoints, and EMG plus single-leg hop distance (and limb symmetry index) were assessed at 12 months.
• Activity of key quadriceps and hamstring muscles was recorded and functional outcomes were reported, while comparing involved and noninvolved limbs.

TAKEAWAY

• Patients who underwent ACL reconstruction had smaller JPS absolute angle error than control individuals at all timepoints (P < .05 for all) and showed persistent neuromuscular alterations in both limbs across tasks.
• During stair descent, vastus lateralis activity was reduced in the ACL involved limb compared with control during pre-activation and weight acceptance (P < .05 for all), and the noninvolved limb showed a reduction only at 6 months (P = .045).
• In the single-leg hop test, vastus medialis and vastus lateralis activity were reduced during the landing phase compared with control individuals (P < .01 for both), and semitendinosus activity was also lower (P < .001).
• No significant differences in cortical activity were observed between patients who underwent ACL reconstruction and control individuals at any timepoint.

IN PRACTICE

"It may be advisable to incorporate targeted neuromuscular and motor relearning interventions, in addition to more comprehensive assessments, into rehabilitation and return-to-sport decision-making processes," the authors of the study wrote.

SOURCE

The study was led by Aglaja Busch, University of Potsdam in Germany, and Bern University of Applied Sciences in Switzerland. It was published online on August 11 in Scandinavian Journal of Medicine & Science in Sports.

LIMITATIONS

Participants were limited to those who had undergone a single surgical procedure. The content and frequency of rehabilitation were not controlled. Participants used a self-selected pace during the JPS test and stair descent, which may have affected the EMG recordings.

DISCLOSURES

The study received funding from the Swiss National Science Foundation. The authors reported no relevant conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.