Hammer Toes: Causes, Risk Factors, and Prevention

What is the cause of hammer toes?

Hammer toes are primarily caused by an imbalance in the muscles, tendons, or ligaments that keep the toe straight, often exacerbated by improper footwear, specific foot structures, or underlying medical conditions.

Understanding Hammer Toes

A hammer toe is a deformity of the second, third, or fourth toe, causing it to bend or buckle at the middle joint (proximal interphalangeal joint, or PIPJ), resembling a hammer. This bending can lead to pain, corns, calluses, and difficulty finding comfortable footwear, and over time, the deformity can become rigid.

Primary Causes of Hammer Toes

The development of hammer toes is multifactorial, stemming from a combination of biomechanical issues and external pressures.

• Improper Footwear: This is arguably the most common and preventable cause.

  • High Heels: Force the foot into an unnatural position, pushing the toes forward and jamming them into the shoe's toe box, causing them to bend upwards at the joint.
  • Shoes That Are Too Short or Narrow: Cramp the toes, preventing them from lying flat and forcing them into a bent position, leading to chronic pressure on the joints.
  • Lack of Toe Box Space: Shoes with pointed or shallow toe boxes do not allow adequate room for the toes to extend naturally.
  • Slipping Shoes: If shoes are too loose, the toes may constantly grip the shoe to prevent slipping, leading to muscle overuse and imbalance.

• Muscle Imbalance: The foot contains both extrinsic (originating in the lower leg) and intrinsic (originating within the foot) muscles that control toe movement.

  • An imbalance where the long tendons (flexors and extensors) become stronger or tighter than the small intrinsic foot muscles can lead to the toes being pulled into an abnormal position.
  • Specifically, the flexor muscles overpower the extensors, causing the PIP joint to bend and the MTP (metatarsophalangeal) joint to hyperextend.

• Foot Structure and Genetics: Certain inherent characteristics of a person's foot can predispose them to developing hammer toes.

  • High Arches (Pes Cavus): This foot type can lead to increased pressure on the toes and altered biomechanics, contributing to muscle imbalances.
  • Flat Feet (Pes Planus): While less common, some forms of flat feet can also alter foot mechanics and contribute to toe deformities.
  • Bunions (Hallux Valgus): A bunion, a deformity of the big toe, can push the big toe inwards, crowding the second toe and forcing it into a hammer-like position.
  • Genetic Predisposition: A family history of hammer toes suggests a genetic component, possibly related to inherited foot structure or ligamentous laxity.

• Trauma: Direct injury to a toe can damage the muscles, tendons, or ligaments, leading to a hammer toe deformity.

  • A stubbed toe, broken toe, or other foot injury can alter the biomechanics and lead to a weakened or imbalanced toe.

• Underlying Medical Conditions: Several systemic diseases can contribute to the development of hammer toes.

  • Diabetes: Can cause neuropathy (nerve damage), which may affect the muscles in the feet, leading to weakness, atrophy, and subsequent deformities.
  • Arthritis: Inflammatory conditions like Rheumatoid Arthritis can cause joint inflammation, pain, and destruction, leading to deformities in the toes. Osteoarthritis can also contribute to joint changes.
  • Neurological Conditions: Conditions such as Charcot-Marie-Tooth disease (CMT), stroke, or spinal cord injury can result in muscle weakness or spasticity that affects the balance of forces on the toes, leading to contractures.

Pathophysiology: How Hammer Toes Develop

The development of a hammer toe is a progressive process. Initially, the deformity may be flexible, meaning the toe can still be straightened manually. However, over time, the soft tissues around the joint – including the tendons, ligaments, and joint capsule – adapt to the bent position. They shorten and tighten, making the deformity rigid and permanent without surgical intervention. This rigid state is often accompanied by the formation of corns or calluses on the top of the bent joint, or at the tip of the toe, due to chronic friction against footwear.

Risk Factors for Hammer Toes

Several factors can increase an individual's likelihood of developing hammer toes:

• Age: The risk generally increases with age as muscles and tendons can shorten and lose elasticity.
• Gender: Women are more prone to hammer toes, largely due to the common use of high heels and narrow-toed footwear.
• Foot Type: Individuals with high arches or specific foot mechanics are at higher risk.
• Family History: A genetic predisposition to certain foot shapes or muscle imbalances.
• Pre-existing Foot Conditions: Such as bunions or calluses.
• Certain Medical Conditions: As previously mentioned, diabetes, arthritis, and neurological disorders.

Prevention and Management

While some causes like genetics are unavoidable, many cases of hammer toes can be prevented or managed with conservative measures:

• Choose Proper Footwear: Opt for shoes with a wide, deep toe box that allows toes to lie flat and wiggle freely. Avoid high heels and pointed-toe shoes.
• Regular Foot Exercises: Strengthen intrinsic foot muscles with exercises like toe curls, marble pickups, and towel scrunches.
• Stretching: Gently stretch the toes and foot muscles to maintain flexibility and prevent shortening of tendons.
• Orthotics: Custom or over-the-counter shoe inserts can help correct foot imbalances and provide support.
• Early Intervention: Address any signs of toe bending early, when the deformity is still flexible, to prevent it from becoming rigid.

When to Seek Medical Advice

It is advisable to consult a podiatrist or orthopedic specialist if you experience:

• Persistent pain in your toes or feet.
• Difficulty walking or finding comfortable shoes.
• The appearance of corns, calluses, or open sores on the affected toe.
• The hammer toe becoming rigid or worsening over time.

Early diagnosis and intervention can help manage symptoms and prevent the progression of the deformity, potentially avoiding the need for surgical correction.