“The human foot is a masterpiece of engineering and a work of art!” This beautiful saying from Leonardo da Vinci clearly depicts the complex anatomy of the foot and physiological function that is involved in daily activities. It is true most activities and balancing of the upper body involves the use of the foot. But at times a pain at the foot restricts the daily activities. The pain of the foot is spread either on the inner or outer side and rarely may involve the entire foot. Pain is described as lateral foot pain when it is spread over the outer side of the foot. The cause of lateral foot pain may involve skin, muscle, tendon, ligament, joint, and bone. Foot pain should be treated promptly to prevent complications like the stiffness of joints and tendons. The infection of the joint should be treated with antibiotics during the initial stage.1 The current article describes all possible causes of lateral foot pain and we will discuss some of the common causes in detail.
Causes of Lateral Foot Pain
Skin Diseases That Can Cause Lateral Foot Pain
- Boil- Inflammation caused by infection of sweat gland and the hair follicle is known as a boil. Most boils are caused by Staphylococcus and Streptococcus bacteria.
- Impetigo1– Infection of skin, extremely contagious and rapidly spreads to an individual who may be in contact with an individual suffering from this disease.
- Cellulitis2– Infection when spreads in subcutaneous tissue cause inflammation of the dermis and subcutaneous tissue known as cellulitis.
- Skin Injury
- Skin laceration
- Skin Cut
Muscle Diseases That Can Cause Lateral Foot Pain
- Muscle Spasm– Repeated use of foot muscles while playing soccer or rugby causes spasm of foot muscles. Foot muscle spasm is also observed in individuals suffering from dehydration and muscle fatigue.
- Myofascitis- Myofascitis is a microscopic inflammatory disease. The lesion is infiltrated with white blood cells and causes pain. The condition is frequently seen in children following vaccination.3
- Myofascial Pain Syndrome (MFS)4– Myofascial pain syndrome causes multiple trigger point that is often extremely painful. The disease is frequently observed in individuals suffering from autoimmune disease. The disease causes inflammation of connective tissue that lies between the bundle of muscle fibers.
- Muscle Injuries
- Muscle Tear
- Muscle contusion
Tendon Diseases: As A Cause of Lateral Foot Pain
- Tendonitis– Inflammation of the tendon is known as tendonitis. Tendonitis is observed in individuals following excessive repeated use of lower leg as well as during heavy weight lifting in the gym.
- Tendon Injury
- Tendon Contusion
- Tendon Tear
Ligamental Diseases: Cause of Lateral Foot Pain
Ligamental Strain- Ligament fastens adjacent bones. Several ligaments are involved in ankle joint as well as several metatarsal and phalangeal joint. Inflammation of ligament is known as a ligamental sprain. Overstretching of bones of feet or twist of the lateral side of the foot causes superficial damage to the ligament that results in ligamental inflammation.
Joint Diseases: Cause of Lateral Foot Pain
Joint Infection- Also known as septic arthritis. Joint infection is caused by Staphylococcus, Streptococcus and Gonococcus bacteria.
- Subluxation- Partial dislocation of ankle or metatarsal joint is known as subluxation.
Bone Diseases That Can Cause Lateral Foot Pain
Cancer: Bone tumor
Common Causes of Lateral Foot Pain Or Pain In The Outer Side Of The Foot:
There are a number of diseases and conditions as mentioned above which causes pain on the outer side of the foot. The following conditions are known to frequently cause lateral foot pain:
Tarsal Coalition Causing Lateral Foot Pain5–
The tarsal coalition leads to foot pain on the outer side only in one in a hundred cases. The Tarsal Coalition is a condition caused by the fusion of the two tarsal bone at the back of the foot on the lateral side. The tarsal bone involved is cuboid, cuneiform, and navicular bone. Though it is one of the rare conditions leading to lateral foot pain, it would be fair enough to be included under this list. It is a congenital problem and symptoms may include pain, fatigue, flat feet, and abnormal or improper walking.
Inversion Sprain/Ankle Sprain6: Cause of Lateral Foot Pain-
Ankle sprain has remained one of the major causes leading to lateral foot pain or Pain on the outer side of the foot. Studies have found that about 85% of ankle injuries lead to lateral foot pain. Symptoms include foot pain, swelling, bruising and instability.
Cuboid Syndrome: Cause of Lateral Foot Pain7–
A cuboid is one of the seven tarsal bones that is located on the lateral side of the foot. Too much of traction over the cuboid leads to a dislocation of this tarsal bone and causes the Cuboid syndrome. This Cuboid syndrome is considered one of the major causes of lateral foot pain. Pain is located over the outer side of the foot. Symptoms under this condition may include pain on the lateral (outer) side of the foot, especially during the weight-bearing acts which may provoke the significant risk of ankle inversion sprain and significant excessive pronation.
Peroneal Tendonitis8: As A Cause of Lateral Foot Pain:
Repetitive tension on the peroneal tendon leads to the Peroneal Tendonitis. Peroneal tendonitis is a condition that leads to pain on the lateral side of the foot and around the heel. Excessive running, abnormal positioning of the foot and ankle sprain can cause Peroneal Tendonitis. Common symptoms include pain, irritation, inflammation, and degeneration.
Corns and Calluses: Cause of Lateral Foot Pain-
There can also be lateral foot pain caused due to the growth of corns and calluses. Though these corns and calluses develop at any part of the foot, it is most commonly seen on the top and the lateral sides. Corns are usually painful and deeper, though calluses are painless. This occurs mainly due to repetitive stress on a portion of the skin on the foot and the skin, in turn, forms multiple layers to protect deeper tissue or subcutaneous tissue.
Lateral Foot Pain Caused Due to Stress Fractures: –
Repetitive sports or physical activities lead to a small fracture on one of the foot bones. The stress fracture of one of the lateral (outer) bone causes lateral foot pain. Lateral foot pain due to stress fractures may be caused only if the fracture has occurred in the calcaneus or navicular bones, or the metatarsals depending upon their location. Symptoms here may be mild at the initial stage but may worsen gradually.
Lateral Foot Pain Caused Due to Hallux Valgus:
This is commonly called as Bunions and is a kind of bone deformity, which leads to a condition where the big toe rotates inwards and starts pointing towards the other toes of the foot. This, in turn, causes severe lateral foot pain when an individual puts most of the weight on the lateral side while walking or standing. The pain on the lateral side of the foot is associated with the symptoms like inflammation, redness, and swelling of the big toe.
Arthritis: Cause of Lateral Foot Pain-
Lateral leg pain in an elderly individual is frequently caused by either osteoarthritis or Rheumatoid arthritis. Rarely gout, psoriatic arthritis or infected arthritis causes inflammation of ankle joint or metatarsal joint. Arthritis involving foot joint located over the lateral side may also be one of the leading causes of lateral foot pain. Arthritis can be either of inflammatory type, i.e. Rheumatoid arthritis or may be of the degenerative type, i.e. Osteoarthritis. Usually, rheumatoid arthritis causes lateral foot pain.
- Management of impetigo and cellulitis Simple considerations for promoting appropriate antibiotic use in skin infections, Lynette Kosar, MScInformation Specialist for the RxFiles Academic Detailing Program for the Saskatoon Health Region in Saskatchewan and Assistant Clinical Professor in the College of Pharmacy at the University of Saskatchewan in Saskatoon., Tessa Laubscher, MB ChB CCFP FCFP
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