Analysis of muscle synergies and activation–deactivation patterns in subjects with anterior cruciate ligament deficiency during walking

Abstract

Background: The knowledge of muscle activation patterns when doing a certain task in subjects with anterior cruciate ligament deficiency could help to improve their rehabilitation treatment. The goal of this study is to identify differences in such patterns between anterior cruciate ligament-deficient and healthy subjects during walking.Methods: Electromyographic data for eight muscles were measured in a sample of eighteen subjects with anterior cruciate ligament deficiency, in both injured (Ipsilateral group) and non-injured (Contralateral group) legs, and a sample of ten healthy subjects (Control group). The analysis was carried out at two levels: activation-deactivation patterns and muscle synergies. Muscle synergy components were calculated using a non-negative matrix factorization algorithm. Findings:The results showed that there was a higher co-contraction in injured than in healthy subjects. Although all muscles are activated similarly since all subjects developed the same task (walking), some differences could be observed among analyzed groups.Interpretation: The observed differences in the synergy components of injured subjects suggested that those individuals alter muscle activation patterns to stabilize the knee joint. This analysis could provide valuable information for the physiotherapist to identify alterations in muscle activation patterns during the follow-up of the subject's rehabilitation.

Muscle synergy analysis in transtibial amputee during ramp ascending activity

“…The number of synergies were similar in healthy and amputee groups which suggested that the complexity of muscle synergy are analogous due to similar control strategy used in the central nervous system (CNS). This study supports the findings of the [8] which analysed subjects with ACL deficiency. The VAF c analysis showed a higher VAF c using 5 synergies however, 4 synergies were believed to provide more distinct synergy groups of muscle EMG contents.…”

“…In all the studies associated with walking, a very insignificant change has been shown in the activation profiles however, a considerable difference has been illustrated in the muscle weightings. Other groups applied the NNMF technique to investigate the difference between healthy and pathological populations [6,8]. Clark et al [6] reported, in post-stroke subjects, similar activation profiles with fewer synergies were required to have a high VAF during walking when compared to healthy subjects.…”

“…Clark et al [6] reported, in post-stroke subjects, similar activation profiles with fewer synergies were required to have a high VAF during walking when compared to healthy subjects. Serrancoli et al [8] …”

Changes in synergy of transtibial amputee during gait: A pilot study

“…However, an insignificant change was observed in activation profiles. Several studies implemented NNMF for comparison of healthy and pathological populations [4,5,7,8]. Clark et al [7] reported, lower number of synergy groups were required to achieve a high VAF in post-stroke patients compared to the healthy population.…”

“…Clark et al [7] reported, lower number of synergy groups were required to achieve a high VAF in post-stroke patients compared to the healthy population. Serrancoli et al [8] found, anterior cruciate ligament (ACL) deficiency would cause a slight change in activation profiles of ACL patients compared to HS. In our previous works [4,5], we investigated the difference in muscle synergy components between healthy and elderly TA subjects during ramp ascending and descending.…”