Abstract
Purpose This study is aimed at investigating the effect of low-intensity electrical stimulation on the voluntary activation level (VA) and the cortical facilitation/inhibition of quadriceps in people with chronic anterior cruciate ligament lesion. Methods Twenty former athletes with unilateral ACL deficiencies (ACL group) and 20 healthy subjects (healthy control group) participated in the study. The quadriceps VA level, motor-evoked potential (MEP), short-interval intracortical inhibition (SICI), and intracortical facilitation (ICF) elicited by transcranial magnetic stimulation were tested before and after 30 minutes of low-intensity electrical stimulation (ES). Results Before ES, the quadriceps VA in the ACL lesion legs of the ACL group was lower compared to the legs of the healthy control group (P < 0.05). The MEP sizes in the ACL lesion legs and the healthy control were not significantly different. The ACL lesion legs showed lower SICI and higher ICF compared to the healthy control group (P < 0.05). After ES, the quadriceps VA level increased and the SICI-ICF was modulated only in the ACL lesion legs (P < 0.05) but not in the healthy controls. Conclusions Low-intensity ES can normalize the modulation of intracortical inhibition and facilitation, thereby ameliorating the activation failure in individuals with ACL lesion.
Highlights
The anterior cruciate ligament (ACL) is vulnerable to sports injury and usually leads to severe quadriceps weakness
Before electrical stimulation (ES), one-way ANOVA showed that the voluntary activation level (VA) of the ACL lesion legs (64:92 ± 12:46%) was significantly lower than that of the legs of the healthy control group (Fð1,36Þ = 25:12, P < 0:001)
After 30 minutes of ES, the VA of ACL lesion legs significantly increased from 64:92 ± 12:46% to 72:71 ± 12:47%
Summary
The anterior cruciate ligament (ACL) is vulnerable to sports injury and usually leads to severe quadriceps weakness. Weakness and atrophy persist for years even though reconstruction has been made [1,2,3]. Severe quadriceps weakness and atrophy restricts the functional performance of the knee joint and prevents athletes’ return to sports competitions. Sixty-six percent of athletes returned to sports competition one year after surgical reconstruction [1], and only 55% of athletes returned to preinjury level post surgery [2]. BioMed Research International in the chronic phase of ACL deficiency are not clear. Knowing the mechanism of severe quadriceps weakness at the chronic phase of ACL deficiency and developing a therapeutic strategy are important
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
