Ahem.... this is a stroke patient. Can he sit properly? What is his trunk control in sitting like? what can the upper limb do? has he had any physio previously or nothing for two years? This is probably not just quadriceps, standing needs more than quads and it will need a neurological physio approach and not only an orthopaedic approach with SLR. Has he Symptoms of sensory deficit/neglect /perception problems.? More information please to help you more.