@ryan.foley.physio: Some people with knee joint pain from osteoarthritis have increased pain as they hold their knee in extension This is what often creates pain during the straight leg raise exercise, as it requires you to hold the knee in extension & dynamically move the hip An alternative I use to still try to get activation across the front of the thigh is this standing hip flexion hold with dynamic knee motion Hold the hip in slight flexion with support from a chair behind, and then slowly straighten the knee & bend back to the start You do not have to straighten the knee fully here - just go short of full extension Going in and out of that position is typically much more tolerable for people instead of holding in a straightened position for reps The goal here is to improve the muscle activation across the front of the thigh to improve the brains awareness of that area