ObjectiveTo explore the correlation among knee hyperextension angle, lower limb joints kinematics parameters and the activation of main muscles of lower limb in stroke hemiplegic patients with knee hyperextension during walking. MethodsFrom August, 2020 to September, 2021, 24 stroke hemiplegic patients with knee hyperextension and 24 healthy subjects matched with sex, age, height and body mass with knee hyperextension were analyzed with three-dimensional gait analysis system and the wireless surface electromyography acquisition system, to record the range of motion of pelvis, hip, knee and ankle joints in sagittal plane, and the activation of bilateral gluteus maximus, biceps femoris, vastus medialis and gastrocnemius medialis. ResultsAs the maximum of knee hyperextension, range of motion of the joints in sagittal plane and the activation of the muscles were different between the patients and the healthy subjects during the single-support phase of walking (|t| > 3.080, P < 0.01), and the maximum of knee hyperextension correlated with the activation of gluteus maximus in the patients (r = -0.532, P < 0.01), and the range of motion of ankle plantar flexion in both the patients and the healthy subjects (r > 0.686, P < 0.001). ConclusionThe correction for knee hyperextension gait in stroke hemiplegic patients may not only need to pay attention to knee joint control, but also need further treatment of ankle control and hip muscle function.