Objective: To investigate the postural control patterns and muscle coordination patterns during sit-to-stand (STS) in individuals with a history of ankle sprain (HAS), providing a theoretical basis for optimizing rehabilitation interventions. Methods: Twelve participants with a history of ankle sprain were recruited and matched with twelve healthy controls. STS movements were captured using an infrared motion capture system and the Delyse surface electromyography (EMG) system. The Center of Pressure (COP) and Center of Mass (COM) metrics were calculated using Visual 3D and Matlab software. Muscle coordination patterns were computed using the Gaussian non-negative matrix factorization algorithm in Rv4.4.2. Results: During the pre-seat-off phase, the ankle sprain group exhibited lower sample entropy in the anterior-posterior direction of COP and lower frequency and sample entropy in the mediolateral direction compared to the control group (P < 0.05). Additionally, the sample entropy and frequency of COM in the anterior-posterior direction were significantly lower in the ankle sprain group than in the control group (P < 0.05). During the post-seat-off phase, the ankle sprain group demonstrated lower mediolateral COM momentum and lower anterior-posterior sample entropy than the control group (P < 0.05). Regarding muscle synergy, both groups exhibited four synergy modules, with the half-width of synergy module 3 being significantly higher in the ankle sprain group than in the control group (P < 0.001). Conclusion: Compared to healthy individuals, individuals with a history of ankle sprain exhibit distinct postural control strategies and muscle synergy patterns during the sit-to-stand (STS) task. Specifically, they compensate for insufficient ankle synergy by enhancing proximal lower limb muscle coordination, thereby demonstrating a more stable mediolateral postural control strategy. However, long-term reliance on proximal compensation may lead to deterioration of the kinetic chain function and increase the risk of chronic ankle instability.