Abstract: Objective To observe the effects of systems of progressive resistance exercise on lower limb extensors （quadriceps femoris） of stroke patients. Methods 89 stroke patients with weak lower limbs were randomly divided into progressive resistance exercise group (n=46) and control group (n=43), both receiving corresponding treatment for 4 weeks. They were assessed with Manual Muscle Test (MMT), integrated electromyogram (iEMG) and root mean square (RMS) of surface electromyography on quadriceps femoris before and after the treatment. Results The incidence of improvement with MMT was 94.3% in progressive resistance exercise group, and 63.8% in control group （P<0.01）. The iEMG and RMS of the exercise group was significantly higher than that of the control （P<0.01）. Conclusion The systems of progressive resistance exercise could improve the muscle strength of lower limbs extensors of stroke patients more effectively.

Key words: systems of progressive resistance exercise, stroke, quadriceps femoris, muscle strength, surface electromyography