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OA

Objective To investigate the lower limb muscle synergy patterns during jumping in patients after anterior cruciate liga-ment reconstruction(ACLR). Methods From 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 Universi-ty.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,vari-ance accounted for,synergy structure(muscle weight)and activation coefficient were extracted. Results Three types of muscle synergy patterns were identified on the affected side and contralateral side of the observa-tion 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 af-fected side than on the contralateral side(P<0.05).For Synergy 2,the weight of lateral gastrocnemius and sole-us 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 Syn-ergy 3 were delayed bilaterally(P<0.05). Conclusion Patients after ACLR exhibit altered structural and temporal characteristics of lower limb muscle synergy dur-ing jump task.The hamstrings show increased participation during the pre-activation phase,and calf muscles un-dertake more stabilizing functions during the landing phase.