Foot drop is a symptom or result of an underlying problem. A foot drop can be a result of one or a combination of three categories:
Muscle damage - when the anterior (front) portion of your leg is injured.
Skeletal or anatomical abnormalities affecting the foot -may be congenital.
Nerve damage - The Peroneal nerve which wraps from the back of the knee to the front of the shin, is the one that is injured. Peroneal nerve supplies motor power and sensation to the muscles that lift the foot up (dorsiflexion). Because it sits very close to the surface, it may be damaged easily. When this nerve is injured, foot drop is the usual result. So my answer to your question is no. There is no direct relationship between tight hip flexors and foot drop.