To point my toes I have to straighten my whole leg (photo on left). To bend my ankle I have to bend my hip and knee (photo on right).
Here is a synergy-related problem that my leg brace corrects. My weak hip and knee flexors don't lift my leg high enough to clear my toes as I take a step. My leg is mostly straight when I swing my leg to take a step so the extension synergy forces my toes to point. Both weak hip flexors and the extension synergy produce foot drop which makes me stub my toes (photo on left). The brace holds my toes and ankle up as I walk. I faithfully wear my leg brace because it prevents falls. Two trips to the emergency room after bad falls were enough for me.