Foot and Ankle Biomechanics and Pathologies

What is Hammer Toes?

A contracture deformity of digits secondary to changes in intrinsic muscles over a long period of time.

What are the characteristics of Hammer Toes?

Proximal phalanx displaced dorsally on met heads, intermediate phalanx plantarflexed on proximal phalanx, and distal phalanx is extended.

In which type of feet are Hammer Toes more commonly seen?

Pronated feet.

What are Claw Toes?

A condition commonly seen in cavus feet secondary to a high declination angle of the metatarsals.

What can cause Claw Toes?

Cavus feet or severely pronated feet where metatarsals are unstable.

What is the mechanism that leads to Claw Toes?

Both conditions can predispose digits to buckling by impairing intrinsic function.

What happens to the long flexors in Claw Toes?

They start the buckling process.

How do EDL and EDB respond in Claw Toes?

They accommodate changes by contracting and stabilizing digits at the metatarsophalangeal joint (MPJ).

What is the result of dorsal capsular structures contracting in Claw Toes?

It may lead to ankylose of the proximal interphalangeal joint (PIPJ).

Where does callus formation occur in Claw Toes?

At the proximal interphalangeal joint and tips of digits.

What is Mallet Toes?

A hammer digit that only has contracture at the distal phalanx (plantarflexed).

What is Hallux Valgus?

A condition where the hallux is everted or rotated into valgus.

What causes Hallux Valgus?

Caused by a pronated foot resulting in a hypermobile 1st ray.

What role does the peroneus longus play in Hallux Valgus?

It fails to stabilize the 1st ray.

What happens to the abductor hallucis in Hallux Valgus?

It gets stretched by pronation, preventing it from applying plantarflexion on the 1st ray.

What is Hallux Limitus?

Inability to dorsiflex the hallux 65 degrees at the metatarsophalangeal joint (MPJ).

What must the 1st ray do for the hallux to dorsiflex properly?

The 1st ray must plantarflex.

What can cause Hallux Limitus?

Short 1st met, long 2nd met, long 1st met, or dorsiflexed 1st ray.

What occurs when the 1st ray dorsiflexes in Hallux Limitus?

The hallux jams into the 1st met head, preventing adequate dorsiflexion.

What is Metatarsalgia?

A non-specific term for pain in the forefoot at the metatarsal level or metatarsophalangeal joints (MPJs).

What are common causes of Metatarsalgia?

Arthritis, occlusive or spastic vascular conditions, neuropathies, and trauma.

What is the most frequent cause of Metatarsalgia?

Microtrauma caused by abnormal pronation of the foot during propulsion.

What does Metatarsalgia result in?

Hypermobility of metatarsals and proximal phalanges.

What is the relationship between shearing callus and Metatarsalgia?

Tissue trauma with metatarsalgia is a preliminary cause of shearing callus.

What leads to excessive met head shearing?

A hypermobile foot during propulsion.

What are the consequences of excessive trauma in shearing callus?

Inflammation, hyperplasia of tissues, and reduced exfoliation of skin.

What is a Neuroma?

A condition resulting from shearing between metatarsals, associated with abnormal pronation during propulsion.

What happens to subcutaneous tissues in a Neuroma?

Trauma results in progressive fibrosis around the neurovascular bundle.

What effect does increased fibrosis have in a Neuroma?

It cuts off blood supply, causing pain.

What is the significance of the shape of the 1st met head in Hallux Valgus/Limitus?

A square shape with a central ridge is more stable and will almost always have limitus, while a round shape usually has valgus.

What is the role of the intrinsic muscles in Hammer Toes?

Changes in intrinsic muscles lead to the contracture deformity.

What is the position of the proximal phalanx in Hammer Toes?

Displaced dorsally on the metatarsal heads.

What happens to the distal phalanx in Hammer Toes?

It is extended.

What is the common foot type associated with Claw Toes?

Cavus feet.

What is the role of the plantar fat pad in Claw Toes?

Displaced anteriorly, resulting in shear callus under met heads.

What is the primary cause of pain in Metatarsalgia?

Microtrauma due to abnormal foot mechanics.

What is the relationship between callus formation and foot mechanics?

Callus formation is a response to increased pressure and friction on the skin.

What is the primary treatment approach for Hammer Toes?

Correcting the underlying muscle imbalance and providing appropriate footwear.

What is the primary treatment approach for Claw Toes?

Addressing the underlying foot structure and providing orthotics.

What is the primary treatment for Hallux Valgus?

Surgical intervention may be required if conservative measures fail.

What is the primary treatment for Hallux Limitus?

Improving the range of motion and addressing any underlying structural issues.

What is the primary treatment for Metatarsalgia?

Reducing inflammation and addressing the mechanical cause of pain.

What is the primary treatment for Neuroma?

Conservative management including orthotics and possibly injections.

What is the significance of the dorsal capsular structures in Claw Toes?

Their contraction can lead to joint stiffness and deformity.

What is the effect of hypermobility on the 1st ray?

It can lead to instability and contribute to various foot deformities.

What is the role of the abductor hallucis in Hallux Valgus?

It is stretched and unable to stabilize the 1st ray due to pronation.

What is the significance of the retrograde force in Hallux Valgus?

It pushes the 1st metatarsal into adduction while pulling the hallux laterally.

What is the relationship between intrinsic muscle function and foot deformities?

Impairment of intrinsic muscle function can lead to various foot deformities.

What is the role of the long flexors in Claw Toes?

They initiate the buckling process of the toes.

What is the significance of callus formation at the tips of digits in Claw Toes?

It occurs due to the tips being the only weight-bearing part of the toe.

What is the significance of the shape of the 1st met head in Hallux conditions?

It can dictate whether a patient will experience Hallux Valgus or Limitus.

What is the primary cause of shearing callus?

Tissue trauma associated with metatarsalgia.

What is the effect of excessive met head shearing?

It leads to increased tissue trauma and inflammation.

What is the long-term consequence of jamming in Hallux Limitus?

It may lead to degenerative changes and possible fusion of the MPJ.

What is the relationship between abnormal pronation and Neuroma?

Abnormal pronation can lead to shearing between metatarsals, causing Neuroma.

What is the primary cause of pain in Neuroma?

Increased fibrosis that cuts off blood supply to the affected area.

What is the significance of the intermetatarsal neuroma?

It develops in the area of bifurcation of the neurovascular bundle passing into the toes.

What happens to the proximal phalanx in Hammer Toes?

It is displaced dorsally on met heads.

What is the position of the intermediate phalanx in Hammer Toes?

It is plantarflexed on the proximal phalanx.

What is the position of the distal phalanx in Hammer Toes?

It is extended.

How do EDL and EDB respond to Claw Toes?

They accommodate the change by contracting and remaining contracted to stabilize digits at the MPJ.

What is the result of dorsal capsular structures contracting at the MPJ in Claw Toes?

The PIPJ may ankylose.

Where is callus formation typically seen in Claw Toes?

At the proximal IPJ and tips of digits.

What causes Hallux Valgus/Limitus?

Both are a result of a hypermobile 1st ray.

What is the position of the hallux in Hallux Valgus?

The hallux is everted or rotated into valgus.

What is the first stage of Hallux Valgus?

It is characterized by the hallux being everted or rotated into valgus.

What happens to the peroneus longus in Hallux Valgus?

It is unable to stabilize the 1st ray.

What effect does pronation have on the abductor hallucis?

It stretches the abductor hallucis, preventing it from applying plantarflexion on the 1st ray.

What mechanical advantage does the Adductor Hallucis gain in Hallux Valgus?

It pulls the hallux into a valgus position.

What must the 1st ray do for the hallux to dorsiflex adequately?

The 1st ray must plantarflex.

What happens when the 1st ray dorsiflexes in Hallux Limitus?

The hallux will jam into the 1st met head.

What are the consequences of jamming in Hallux Limitus?

It prevents the hallux from dorsiflexing as much as needed, leading to degenerative changes at the MPJ.

What are some causes of Metatarsalgia?

Causes include arthritis, occlusive or spastic vascular conditions, neuropathies, and trauma.

What does hypermobility of mets and proximal phalanges lead to in Metatarsalgia?

It causes gradual stretching of ligaments and capsular structures.

What is the result of tissue inflammation in Metatarsalgia?

It results in pain.

What is Shearing Callus?

A condition resulting from tissue trauma with metatarsalgia.

What causes excessive met head shearing in Shearing Callus?

It is caused by a hypermobile foot during propulsion.

What does excessive trauma lead to in Shearing Callus?

It causes inflammation, hyperplasia of tissues, and reduced exfoliation of skin.

What contributes to callus formation in Shearing Callus?

Hyperplasia of tissues and reduced exfoliation of skin.

What happens to subcutaneous tissues in Neuroma?

Trauma results in progressive fibrosis around the neurovascular bundle.

What is the consequence of increased fibrosis in Neuroma?

It cuts off blood supply, causing pain.

What is intermetatarsal neuroma?

Neuroma that develops in the area of bifurcation of the neurovascular bundle passing into the toes.

What is Heel Spur Syndrome mechanically derived from?

Either pronated or cavus foot.

What happens to the medial band of the plantar fascia in Heel Spur Syndrome?

It is pulled excessively.

What is the result of the excessive pull on the medial band of the plantar fascia?

It causes micro tearing of fascia away from the medial calcaneal process.

Why does pulling occur medially in Heel Spur Syndrome?

Due to greater range of motion (ROM) of the medial column.

What type of onset is associated with Heel Spur Syndrome?

Insidious onset with post-static dyskinesia.

What symptom occurs when moving after being stationary for a while in Heel Spur Syndrome?

Pain.

What happens to venous return when a person is static in Heel Spur Syndrome?

There is less venous return to remove inflammatory products from the site.

What initiates the muscle pumping of veins in Heel Spur Syndrome?

Movement.

What may or may not be seen in Heel Spur Syndrome?

Spur formation.

What causes reactive bone formation in Heel Spur Syndrome?

Increased blood flow to the area of trauma, as the body tries to heal itself.

What is Heel Spur Syndrome?

A condition where the periosteum contains osteoblasts activated by the disruption of the aponeurosis, causing bone to grow outward.

What can cause chronic trauma in Heel Spur Syndrome?

Chronic trauma to the abductor hallucis muscle at its origin can cause the muscle to begin calcifying.

What is plantar fasciitis?

Inflammation of the plantar fascia, most commonly affecting the medial band.

What is a common symptom of plantar fasciitis?

Pain on palpation of the medial band with the hallux dorsiflexed.

What causes arch pain in relation to plantar fasciitis?

Excessive pull or stress on the plantar fascia during gait.

What is an Abductor Hallucis Strain?

A condition that may be mistaken for Heel Spur Syndrome or plantar fasciitis, causing pain on ambulation.

What factors contribute to knee pain due to foot function?

Decreased pronation limits internal leg rotation, causing strain on knee ligaments and reducing shock absorption.

What is Equines in relation to knee pain?

Inability to dorsiflex the foot the necessary 10 degrees needed for normal propulsion, leading to compensatory hyper-extension of the knee.