Curling the toes, known as digital plantar flexion, primarily engages the flexor muscles and their corresponding tendons on the underside of the foot and lower leg. The flexor digitorum longus (FDL) and flexor digitorum brevis (FDB) are the main muscles that curl the four smaller toes. Pain during this motion frequently points to strain or inflammation within these contractile and connective tissues.
Immediate, sharp discomfort often stems from a sudden muscle cramp—an involuntary, painful contraction. Spasms typically occur due to muscle fatigue from overuse, dehydration, or an imbalance of electrolytes (magnesium, potassium, and calcium). Tight or improperly supportive footwear can also overwork the small intrinsic foot muscles, leading to acute pain.
A more persistent pain is flexor tendinopathy, the inflammation or degeneration of the flexor tendons. The flexor digitorum longus tendon runs from the lower leg, behind the inner ankle, and branches out to the toes. Repetitive stress, such as from activities requiring constant push-off, can lead to micro-tears and pain along the tendon’s path, often felt along the underside of the foot. This discomfort is aggravated when the toes are curled because the action puts the damaged tendon under tension and load.
General muscle fatigue or strain from a new exercise regimen or prolonged standing can cause a dull, aching discomfort in the foot arch and toes. Overuse forces soft tissues to work harder, leading to tension most noticeable during toe flexion. Addressing these issues often involves rest and reducing strain on the overstressed muscles and tendons.
Structural Causes Related to Joints and Bone
Pain during toe curling may originate from the underlying skeletal structure, specifically the joints and bones of the forefoot. The metatarsophalangeal (MTP) joints at the base of the toes are frequent sites of pain when structural integrity is compromised. Inflammation of these joints, caused by arthritis, can make any movement, including curling, painful.
Gout, a form of inflammatory arthritis caused by uric acid crystals, commonly affects the big toe joint, making flexing the toe intensely painful. Similarly, a stress fracture—a tiny crack in a metatarsal bone—causes pain exacerbated by the pressure and muscle pull involved in toe curling. The movement puts an abnormal load on the weakened bone, resulting in sharp, localized pain.
Structural deformities like hammertoes, claw toes, or mallet toes involve an abnormal bend in the toe joints, often due to muscle imbalance or ill-fitting shoes. When the foot attempts to curl a deformed toe, strained joint surfaces rub, or tightened tendons pull against the abnormal alignment, leading to discomfort. Bunions (bony bumps at the base of the big toe) also alter forefoot biomechanics, pushing other toes into unnatural positions that hurt when flexed.
Neurological Sources of Foot Pain
Pain felt during toe curling can be traced to irritation or compression of the nerves within the foot, presenting differently than soft tissue or joint pain. Nerve-related pain typically manifests as a distinct burning, tingling, numbness, or electrical sensation that shoots into the toes. This indicates the nervous system, rather than the muscle or tendon, is the source of the distress.
One common nerve-related cause is Morton’s Neuroma, involving the thickening of tissue around a nerve, usually between the third and fourth toes. When the toes curl, the movement compresses the forefoot bones and the inflamed nerve bundle, leading to sharp, burning pain, often described as walking on a marble. This compression is aggravated by narrow shoes or movements that squeeze the metatarsals together.
Another potential neurological cause is Tarsal Tunnel Syndrome, involving the compression of the posterior tibial nerve on the inside of the ankle. While the compression occurs at the ankle, the resulting pain, tingling, and numbness are often felt along the bottom of the foot and into the toes. Toe curling can worsen symptoms by stretching or pulling on the irritated nerve branches. This nerve entrapment can also cause weakness in the foot muscles, making the curling action difficult or painful.
Immediate Relief and When to See a Specialist
For immediate, mild discomfort, simple self-care strategies can help manage symptoms and reduce inflammation. Applying the principles of RICE (Rest, Ice, Compression, and Elevation) is often the first step, especially if the pain is acute or accompanied by swelling. Resting the foot by avoiding activities that trigger pain allows strained tissues to settle.
Applying ice for 15 to 20 minutes several times a day helps reduce localized swelling and numb the pain. Gentle stretching of the calf and foot muscles can also relieve tension and spasms. Switching to comfortable footwear with a wide toe box is crucial, as narrow shoes frequently compress the toes and aggravate underlying conditions.
Seek immediate medical attention if you experience severe pain, sudden inability to bear weight, or signs of infection such as fever, rapid swelling, or spreading warmth and redness. These symptoms may indicate a serious issue like a severe stress fracture or acute inflammation.
Schedule an office visit if the pain does not improve after a few weeks of consistent home treatment, or if swelling persists beyond five days. Burning pain, persistent numbness, or a pins-and-needles sensation, especially if it affects multiple toes, also warrants a visit as these are characteristic of nerve involvement. A specialist can accurately diagnose the underlying cause and recommend targeted treatments such as custom orthotics or physical therapy.