The plantar plate is an important structure of the first metatarsophalangeal joints in the foot. The plantar plate is part of the plantar fascia and is a thickening of the plantar aspect of the joint capsule. Plantar plate dysfunction is a common cause of pain under the first metatarsophalangeal joint. Ultrasound often demonstrates a plantar plate tear that may need surgical repair. The treatment of a plantar plate dysfunction is initially to use something like a metatarsal pad or strapping to plantarflex the toe to allow it to heal. Often a metatarsal pad may need to be used long term.

Sesamoiditis is a common problem in athlete with high loads under the first metatarsophalangeal joint. It is not really a sesamoiditis, as it is an inflammation of the soft tissues around the sesamoid bones at this joint. The pain of sesamoiditis is usually on direct palpation of the area. Imaging is sometimes useful to rule out a fracture of the sesamoid bone. The reason for the higher loads is due to the structure of the foot, most common a higher arched foot with a plantarflexed first ray which when combined with higher levels of activity can create this problem. Sesamoiditis can also be more common in sports that involve pivoting on the first metatarsophalangeal joint such as tennis. The initial treatment if sesamoidtis is the use to offloading techniques in foot orthoses to reduce the load on this structure. Sometimes adding an anti-shear cover to the foot orthoses will help with the pivoting motions. If conservative measures are not successful, then surgical management such as elevating the first metatarsal or the more drastic measure of removing the sesamoid have been tried for sesamoiditis.

This is a common problem in athletes. Sinus tarsi syndrome generally occurs in two situations that are almost opposite to each other. One is that the structures in the sinus tarsi can be damaged during an inversion ankle sprain. Often this problem goes undetected until some of the original ankle sprain settles. The other condition is an excessively flat or pronated foot that pushes the subtalar joint to its end range of motion and compresses the tissues in the sinus tarsi. In both cases there can be a feeling of instability and pain is generally palpated over the sinus tarsi on the lateral side of the ankle joint.

Treatment is mostly done with physical therapy in both situations. Foot orthotics are generally needed if the causes is a flat pronated foot. Occasionally a series of steroid injections into the sinus tarsi will be helpful.

For the latest on sinus tarsi syndrome, see Podiatry Arena:
What actually hurts in sinus tarsi syndrome
Foot orthotics for sinus tarsi syndrome

Exercise for those with diabetes is extremely important. It is important for general health and fitness as well as weight control. There are also some diabetes specific benefits of exercise for those with diabetes such as assisting in glucose controls and also in type two diabetes its also has the affect of increasing insulin sensitivity. Those with diabetes who exercise need to take precautions such as the timing and amounts of insulin injections relative to the timing of exercise. There is one other problem that those exercising need to be conscious of and that is the ‘diabetic foot’. The foot is at increased risk for damage because of the diabetes and that damage may not be detected. Stress fractures are more common in those with diabetes and in the worse case; a Charcot foot problem may develop. Those with diabetes and sign of peripheral neuropathy are at greater risk for diabetic foot problems and are probably better off avoiding weight bearing exercise and take part in activities like cycling and swimming.

The April 2010 edition of  Podiatry Today magazine has a good update of the latest concepts in Medial Tibial Stress Syndrome by Kevin Kirby. Two interesting key concepts that came through in the review is that there is no agreement on exactly what is the pathological process in the condition – is it a soft tissue traction issue or a bone stress reaction due to tibial bending actions?  The tibial bending moments are a recent consideration in the risk factors for this condition. If medial tibial stress syndrome is due to tibial bending moments, then this has implications for the use and prescription of foot orthotics and running shoes to alter these bending moments. There has been some discussion on this concept for medial tibial stress syndrome.

In a recent edition of Radiological Medicine there is a new study that investigated the use of a weightbearing MRI to assess those with plantar fasciitis. They were able to report that the changes in the MRI signal that was associated with plantar fasciitis when compared by blinded examiners in those without plantar fasciitis. Unlike the usual ultrasound finding, the thickness of the plantar fascia was reduced due to stretching in the weightbearing position compared to the supine position. This is an importantt observation given the emphasis  that gets put on the thickness of the plantar fascia with ultrasound measurement which is done non-weightbearing. The important finding in this study was of 15 cases that they looked at, 4 had partial tears of the plantar fascia visible on the weightbearing MRI. This has implications for sports medicine as a number of the cases of plantar fasciitis that are seen, may infact be partial tears.

A review just published in the British Journal of Sports Medicine looks at how how foot orthotics might work (Foot Orthoses and Gait: A Systematic Review and Meta-analysis of Literature Pertaining to Potential Mechanisms. Br J Sports Med. 2009 Dec 8)

The authors did a systematic review and meta-analysis looking at the evidence for the physiological basis for orthoses under the biomechanical, shock attenuation and neuromotor paradigms. They concluded that:

Based on our review, we conclude with rudimentary guidelines for the prescription of orthosis to individuals with a range of injury histories.

Cuboid syndrome is a common overuse injury on the lateral side of the foot. it is generally thought to occur when the cuboid bone is not stable in the proximal and distal joints it has and contraction of the peroneus longus tendon that passes under the cuboid try to sublux the bone. The symptoms involve pain around the cuboid. Usually some forum of cuboid manipulation is needed to deal with the subluxation. Strapping and or foot orthotics are often also needed to help stabilize the cuboid in its joints.

Severs disease or calcaneal apophysitis is a common problem of the heel in children aged 8 to 12 years. Some recent data on Severs Disease has suggested that the mechanism of injury may be a stress fracture like lesion of the cartilage growth plate. Most cases respond well to a cushioning heel lift, calf muscle stretching and some reduction in activity levels. Some may need foot orthotics or strapping. All cases of Severs Disease are self limiting as the growth plates fuses by around age 16.

Gout is not a common cause of heel pain but gout can affect the subtalar joint, causing pain in the rearfoot. The urate crystals can also deposit in the plantar soft tissue and mimic plantar fasciitis. The differential diagnosis is usually difficult as both can mimic other symptoms. For gout and heel pain, considers a course of colchicine to help in the diagnosis.