Vague foot pain in children may be harmless, but it can indicate bigger problems, as David Baker and Deborah Eastwood explain.
Growing pains in children are usually associated with knees and hips, covered in part I of this survey (SIB 52). However, a variety of practitioners will see children in their clinics complaining of foot pain. Although this is often of minor clinical significance, the practitioner will want to rule out important conditions that may need further investigation and treatment, in order to allay the concerns of parents and reassure the child.
Children need to be given time to adjust to their surroundings and become comfortable if you are going to get a useful history from them. While it is understandable that the parents do most of the talking, the practitioner must take care to listen to what the patient says, too.
Checklist of relevant information
The child should be examined in a comfortable and supportive environment. Initially observe the child walking in their regular footwear and then barefoot with the whole of the lower limbs and feet exposed.
Gait analysis includes assessment of any limp which can be caused by pain, muscle weakness or limb shortening. An exaggerated or ‘odd’ gait should raise the possibility of a psychological element to the symptom complex. Note the overall alignment of the lower limbs: rotational, angular and longitudinal deformities can all cause secondary foot pain.
The childhood habit of tip-toe walking is common and of no intrinsic concern. However, it can result in tight or painful Achilles or traction apophysitis (inflammation of the bony protruberance of the calcaneum) at the point where the tendon inserts on to the heel bone. If the child has recently started toe walking bilaterally without pain, this should ring alarm bells, as rarely but importantly an underlying neuromuscular problem (classically muscular dystrophy) may be the cause. Other important warning signs are unusually bulky calves in the presence of weakness as demonstrated by a positive Gower’s test (the child gets up from the floor in the distinctive manner shown at Figure 1).
Flat feet are common among children. Ask the child to stand on tiptoe. If the medial arch forms then the deformity is ‘flexible’ – possibly linked to general ligamentous laxity and needing no specific treatment apart from reassurance and possibly some footwear modification. The vast majority of young children ‘grow out’ of their flat feet, but taking note of their ethnic origin and family history will help you predict the foot’s future. If the parent has flat feet, the child is less likely to grow out of it. But even so, it doesn’t mean they will necessarily develop problematic symptoms. Some racial groups, notably those of Afro-Caribbean origin or those of Jewish heritage, are prone to flat feet.
The older the child, the less likely it is that the foot posture will change. Orthotic supports are rarely required for the asymptomatic foot but if walking is limited by ‘tired legs’ or discomfort in the foot or calf, supports may be helpful. But note, orthotics do not change the natural history of the shape/posture of the foot. If the medial arch does not appear when on tiptoe, then the child has a rigid flat foot (with a stiff subtalar joint), the causes of which include tarsal coalition (the abnormal union of two or more bones in the hind and mid-foot), juvenile arthritis and subtalar pathology.
Next, examine the foot and ankle. Ask the child to point to the site of pain. Look for any redness, swelling and callosities. Palpate the foot for tender spots. Assess the ankle, subtalar, midfoot and forefoot joints for pain on movement and note the range of movement.
i. Non-specific causes
Trauma to the foot will usually be apparent from the history and examination. But bear in mind the possibility of repeated minor trauma from poorly fitting shoes or the presence of a foreign body such as a needle in the sole of the foot.
Infection of the bone (osteomyelitis) or joints (septic arthritis) is serious and can occur at any age. It usually results from blood-borne infection rather than direct inoculation. Common symptoms include pain, swelling, redness and markedly reduced (and painful) joint movement. The child is usually systemically unwell. These conditions are medical emergencies, so refer without delay if you suspect one.
Stress fractures are most often seen in young people between the ages of 12 and 18. They are caused by repeated loading of an immature bone often as a result of adult sport or dance training methods being applied to the immature skeleton. The common features are activity- related pain with swelling and tenderness. It often takes a bone scan to confirm the diagnosis. Treatment consists of rest and activity modification/restriction, possibly involving the short-term use of splints or casts.
Chronic regional pain syndromes (previously called ‘reflex sympathetic dystrophy’) are rare problems, generally implicating the autonomic nervous system. The salient feature is pain out of proportion to the physical findings or initial trauma – indeed, the precipitating traumatic event may have been so trivial that it has been forgotten. Pain is often burning and not relieved by rest. The physical signs can be variable but include colour changes, sweating and shiny skin. Treatment can be difficult and should involve physiotherapy and pain clinic specialists; an early referral should be sought.
ii. Specific causes
As explained above, the practitioner will need to assess a painful flat foot to determine whether it is flexible or rigid.
A flexible flat foot can give rise to postural foot strain. Reassurance, modification of footwear and, rarely, orthotic support are the treatments. Occasionally specific physiotherapy help is required, perhaps particularly in patients with evidence of more general hypermobility (see SIB 49).
Patients with a rigid flat foot often have lateral hindfoot pain from peroneal muscle spasm. Tarsal coalitions are formed when a cartilaginous bar exists between two bones in the foot. With growth, the cartilaginous bar ossifies, leading to less movement and sometimes more pain as the joint in effect becomes fused. This is usually when the child will present, at about age 10 or older. The most common ‘joints’ involved are the calcaneonavicular and talocalcaneal.
Examination usually reveals an everted flat foot with an obvious valgus heel and a stiff subtalar joint. Diagnosis can be difficult, needing x-ray and CT imaging for confirmation. The condition may be bilateral and patients who have always had a stiff subtalar joint may have developed some additional compensatory movement at the ankle and mid tarsal joints, so care should be taken when comparing one foot with the other for range of movement as both may be restricted even if only one foot is symptomatic.
There may be a suggestion of a bony prominence over the medial aspect of the subtalar joint in the presence of a talocalcaneal bar. Take care to distinguish this from the prominent lump that is found with an accessory navicular and tibialis posterior tendinitis (see below).
Other causes of rigid flat foot include inflammatory arthropathies, infection and, rarely, bone tumours.
|Flexible||Postural foot strain|
Subtalar pathology such as infection or tumour
You are most likely to see traction apophysitis in patients from age 10 upwards. Linked to periods of rapid growth, this trauma occurs after repeated loading at an interface where tendon attaches to bone (apophysis). In the foot it may occur at the junction of the Achilles tendon with the calcaneum, between peroneus brevis and the base of fifth metatarsal, or between the insertion of tibialis posterior and an accessory navicular, if present.
Apophysitis at the Achilles-calcaneal junction is painful and the child may walk on tiptoe in an attempt to off-load the tendon and relieve their pain. X-rays often show fragmentation of the calcaneal apophysis (but this is also seen in asymptomatic patients). The condition is self- limiting; treatment options for symptoms include analgesics, NSAIDs, activity modification and using heel raises (silastic heel cushions). Also sometimes helpful are locally applied heat, and stretching of the Achilles. Historically this condition has been known as Sever’s disease.
Fifth metatarsal apophysitis also affects children at 10 years old or so, with a painful swelling at the base of the fifth metatarsal where the peroneus brevis inserts. Treat as for Achilles apophysitis, with the addition of wide or soft footwear as appropriate.
An accessory navicular usually fuses with the main body of the navicular at skeletal maturity. In fewer than 2% of cases this fusion does not occur and a fibrous joint develops between the two. Because the tibialis posterior tendon is attached to the accessory navicular, the pull of this causes stress at the fibrous union similar to apophysitis. Treatment is again largely symptomatic but it may help to put the child’s foot in plaster for a short time such as two weeks, to rest the area. If symptoms are persistent and severe, surgery may be best to remove the accessory navicular.
|Achilles tendon||Calcaneum (Sever’s disease)|
|Peroneus brevis tendon||Base of fifth metatarsal|
|Tibialis posterior tendon||Accessory navicular|
Certain bones in the body have a tendency to develop deficiencies in their blood supply which can lead to collapse of the bone. This is known as avascular necrosis and in the foot the bones affected are the navicular and the metatarsal heads. Diagnosis may be made on history and examination and confirmed by the almost classical appearances on X-ray.
Avascular necrosis of the navicular (Kohler’s disease) is usually found in children aged about five. The presenting symptom is foot pain and on examination the foot is held slightly supinated and there is tenderness and swelling over the navicular. The condition resolves spontaneously; treat symptomatically. Severe symptoms may warrant rest in a plaster. Over the course of one to two years the blood supply is re-established and usually the navicular resumes its normal shape and size.
Freiberg’s Infraction is avascular necrosis of the metatarsal head. It causes metatarsalgia (pain in the ball of the foot), usually after the age of 10, and is more common in girls. The second metatarsal is the most commonly affected. Alongside foot pain, symptoms usually include joint stiffness, obvious swelling and tenderness over the metatarsal- phalangeal joint. Treatment is initially supportive, with footwear modification and orthotics. Physiotherapy can help to maintain range of movement and correct gait patterns. Surgery is reserved for unremitting cases.
The plantar fascia can become inflamed and cause severe pain under the heel. Predisposing factors are sports involving a lot of ground impact. Treatment involves activity modification, soft gel heel inserts and stretching of the plantar fascia and the Achilles. In children local steroid/anaesthetic injections are rarely appropriate.
David Baker is a specialist registrar in orthopaedics in south Wales with a special interest in paediatrics.
Deborah Eastwood MB FRCS is a consultant paediatric orthopaedic surgeon, based at the Hospital for Sick Children, Gt Ormond St, London and the Royal National Orthopaedic Hospital. Her special interest is in working with disabled children in sports and nonsporting contexts
Illustrations by Viv Mullett