One cause of hammertoes
One cause of hammertoes Take a look at this gals left foot. Notice the high, cavus arch as well as increased tone in the long flexors of the toes. Is it any wonder she has weakness of the long extensors on that side? Look at the other picture and note that she has a shorter leg on the left. Yes, it is anatomical and tibial on clinical exam. She also has limited ankle dorsiflexion and hip extension bilaterally, left greater than right. When the foot is cavus it puts an increased stretch on the long flexor muscles of the foot because the metatarsalphalangeal joint is in relative extension. More than likely this will activate the Ia afferents from the muscle spindles causing more tone in the flexors. Yes, that will decrease over time but you will also increase the relative length of the long flexor tendons and decrease the length of the long and short extensor tendons.
More tone in the flexors equals less tone in the extensors. Combine this with a lack of ankle dorsiflexion and hip extension and it’s prescription for more hammertoes. In addition, she has an anatomical short leg on the left putting that foot in relative supination with respect to the right. She will need to claw her toes in an attempt to create stability on that side. The fix will be getting better control and strength in the long extensors and improving ankle dorsiflexion and hip extension.