Objective: To explore limb coordination patterns and energy flow strategies during the Sit-to-Stand (STS) task in individuals with Patellofemoral Pain (PFP), providing theoretical evidence for the pathogenesis of PFP and aiding in the development of treatment and rehabilitation strategies for PFP patients. Methods: This study recruited 36 participants for the STS test, divided into a Unilateral Patellofemoral Pain Group (UPFPG), Bilateral Patellofemoral Pain Group (BPFPG), and a Control Group (CG) based on the number of limbs affected by patellofemoral pain. An infrared motion capture system (Qualisys, Sweden, sampling frequency 200Hz) and a 3D force plate (Kistler, Switzerland, sampling frequency 1000Hz) were used for motion capture. Biomechanical indicators of the trunk, pelvis, and lower limbs were calculated using Visual 3D and Matlab. Coupling angles was used to represent coordination patterns via vector coding; the segmental net energy integration method was used to calculate energy flow within segments at each stage, with positive values indicating energy input and negative values indicating output. Statistical analysis was performed using one-way ANOVA, with a significance level set at 0.05. Results: In the frontal plane coordination pattern, the proximal coordination mode frequency of the pelvis-hip coordination in the FMP phase was higher in UPFPG than in BPFPG (P=0.024). In the MTP phase, the frequency of in-phase coordination in the trunk-pelvis coordination was higher in UPFPG than in BPFPG (P=0.023), while the frequency of distal coordination was higher in CG than in UPFPG (P=0.032). For the knee-ankle coordination pattern, the frequency of distal coordination in CG was lower than that in UPFPG and BPFPG (P=0.025, P=0.005). In segmental energy flow, during the FMP phase, the energy output from the pelvis in MP was higher in BPFPG than in CG (P=0.021). Conclusion: PFP affects energy flow patterns and frontal plane coordination patterns during the STS task. Specifically, individuals in the UPFPG may engage in lateral pelvic and ankle movements as a dynamic compensation for patellofemoral joint pressure, whereas individuals in the BPFPG appear to increase pelvic region energy output and employ a more complex whole-body coordination pattern to compensate for functional deficits in the knee caused by PFP.