A range of alternative exercises work the quadriceps femoris muscle in the same way sissy squats do. Albeit, with less stress being placed on the knees.
How To Do a Sissy Squat and the Benefits
The 12 Best Sissy Squat Alternatives for Bigger, Stronger Quads – Fitness Volt
The 12 Best Sissy Squat Alternatives for Bigger, Stronger Quads – Fitness Volt
What are some dumbbell exercises that can replace barbell squats or bench presses, and why are they effective? - Quora
Stop Doing Sissy Squats: 12 Superior Alternatives — Advanced Human Performance Official Website
The 12 Best Sissy Squat Alternatives for Bigger, Stronger Quads – Fitness Volt
Stop Doing Sissy Squats: 12 Superior Alternatives — Advanced Human Performance Official Website
The 12 Best Sissy Squat Alternatives for Bigger, Stronger Quads – Fitness Volt
How to build big strong legs without squats or deadlifts - Quora
HOW TO: SISSY SQUATS Muscles worked: - quads (and a little of core