Some people find it difficult to touch their toes with their fingers while bending down.
This is a sign of a major health issue due to lack of flexibility.
Flexibility is needed for proper blood circulation, and muscle elasticity and therefore, lack of flexibility can lead to certain kinds of injuries while playing sports or in daily activities.
Added to that, the inability to touch the toes without bending the knees indicates that hamstrings are tight because of the fascia. Or the hip muscles are not flexible enough and thus the person can have backache and other problems.
Or it might be because of abnormal fat deposits in the belly as a result of physical inactivity.