Activation timing and synergy characteristics of lower limb muscles in patients after anterior cruciate ligament reconstruction
10.3969/j.issn.1006-9771.2026.06.009
- VernacularTitle:前交叉韧带重建术后患者下肢肌肉的激活时序与协同特征
- Author:
Peng CHEN
1
;
Sizhuo ZHANG
2
;
Ling WANG
1
;
Huiwu ZUO
1
;
Cheng ZHENG
3
Author Information
1. School of Exercise and Health, Shanghai University of Sport, Shanghai 200438, China
2. Wuhan Business University, Wuhan, Hubei 430056, China
3. Department of Orthopedics, Affiliated Hospital of Wuhan Sports University, Wuhan, Hubei 430079, China
- Publication Type:Journal Article
- Keywords:
anterior cruciate ligament reconstruction;
muscle synergy;
lower limb;
non-negative matrix factorization
- From:
Chinese Journal of Rehabilitation Theory and Practice
2026;32(6):708-720
- CountryChina
- Language:Chinese
-
Abstract:
ObjectiveTo investigate the lower limb muscle synergy patterns during jumping in patients after anterior cruciate ligament reconstruction (ACLR). MethodsFrom March to November, 2022, 23 patients after ACLR were enrolled as observation group, and 24 healthy ones matched in height, body mass and exercise level were recruited as control group at Wuhan Sports University. Surface electromyography (sEMG) data of lower limb muscles were collected during a single-leg vertical jump task. Non-negative matrix factorization was applied for synergy analysis. The number of synergies, variance accounted for, synergy structure (muscle weight) and activation coefficient were extracted. ResultsThree types of muscle synergy patterns were identified on the affected side and contralateral side of the observation group, and the control group. For Synergy 1, the weight of biceps femoris was higher on both the affected and contralateral sides than in the control group (P < 0.01); the weight of semitendinosus was higher on the affected side than on the contralateral side (P < 0.05). For Synergy 2, the weight of lateral gastrocnemius and soleus were higher on both sides of the observation group than in the control group (P < 0.05). For Synergy 3, the weight of gluteus maximus was lower on the affected side than on the contralateral side and in the control group (P < 0.05); the weight of tibialis anterior was higher on the affected side than on the contralateral side and in the control group (P < 0.001); the weight of vastus lateralis was lower on the contralateral side than on the affected side and in the control group (P < 0.001). In the observation group, the peak activation time and stop time of Synergy 3 were delayed bilaterally (P < 0.05). ConclusionPatients after ACLR exhibit altered structural and temporal characteristics of lower limb muscle synergy during jump task. The hamstrings show increased participation during the pre-activation phase, and calf muscles undertake more stabilizing functions during the landing phase.
