The above flat feet can be very stable, but if over pronated, they are probably not. This blog post summarizes the injuries or pain syndromes that have been tied to over pronation. And, your expectation should be if you can help with the reduction of overall pronation, that these symptoms will improve. Today, I will just summarize these problems that are linked to over pronated feet.
Here is a list I give to my students that can be caused by excessive pronation. The list was generated by various articles, but mainly years of evaluation of what symptoms could improve if I corrected for excessive pronation. The list for pronation is founded on the problems or instabilities produced by over pronation: medial instability, excessive rotation or torque on various structures, poor shock absorption if you are fully pronated, increased medial foot weight bearing, and lateral knee weight bearing. They include:
- First metatarsal phalangeal joint pain with functional hallux limitus.
- Sesamoid Injuries can be caused by pronation injuring the sesamoids.
- Bunions are caused by the chronic nature of pronation overloading the medial side of the foot causes instability of the first metatarsal first cuneiform joint leading to slow first metatarsal drift in abduction, inversion, dorsiflexion.
- Second metatarsal phalangeal joint capsulitis where an unstable 1st metatarsal puts more weight on the second metatarsal.
- Metatarsalgia can be caused by the shearing forces of forefoot abduction on the rearfoot.
- Second metatarsal stress fractures can be caused by the overload onto the 2nd metatarsal from an unstable 1st metatarsal.
- Morton’s neuromas or neuritis can be caused by instability of the metatarsals when the foot stays too pronated (loose bag of bones) and there is excessive intermetatarsal motion.
- Hammertoes can be caused by lack of stability in the midfoot, so the toes claw the ground in an attempt to gain stability.
- Intrinsic muscle strain occurs when the muscles have to work overtime stabilizing the foot, especially the digits at propulsion.
- Plantar fasciitis is an overstretching of the arch with pronation that probably is related to microtearing.
- Anterior tibial tendonitis develops with excessive pronation and the attempt at decelerating that pronation at heel contact.
- Lateral sinus tarsitis, also called sinus tarsi syndrome, is normally lateral impingement with marked eversion where the medial structures are stretched and the lateral structures pinched.
- Cuboid syndrome is where the cuboid is not stable and the tissue around it get irritated. Excessive pronation means medial weight bearing, but lateral foot instability.
- Lateral ankle impingement, like sinus tarsi syndrome, where high levels of pronation cause the everting calcaneus to collide with the medial side of the lateral malleolus.
- Posterior tibial injuries including accessory navicular syndrome. The posterior tibial tendon is the most important and most direct decelerator of subtalar joint pronation and supporter on the medial longitudinal arch.
- Tarsal tunnel syndrome can have a mechanical cause or aggravating factor where pronation of the foot at the ankle can cause a stretching of the medial ankle structures for a prolonged or exaggerated timeframe. Also, swelling from tenosynovitis of any of the three medial ankle tendons can cause posterior tibial nerve compression.
- Peroneus longus strain can occur from overpronation where the tendon attempts to stabilize the medial column where it attaches.
- Achilles strain can occur from overpronation as the achilles medial fibers fight to decelerate pronation. The achilles is a sagittal plane mover primarily, and can get stressed and twisted when the heel is everted to the tibial during push off from overpronation.
- Tibial stress fractures can be caused by overpronation causes excessive internal tibial rotation. Some of the biggest muscles that decelerate this pronation attach on the tibia called the posterior tibial and soleus. The pull can be so great that the tibia can break. Since knee motion can be dependent or independent on foot motion, there are many individuals that have tremendous foot pronation with no patellar internal rotation. In these situations, the torque that naturally goes up the leg into the knee and hip, is stopped in the tibia or knee abruptly leading to tibial stress.
- Medial soleus strain can be caused with overpronation. The soleus attaches into both the proximal aspects on the posterior tibia and posterior fibula. It not only works to plantar flex the ankle at push off, but supinates the subtalar joint to help with the overall external leg rotation of the lower extremity. If the foot is held in a prolonged pronated position into the propulsive phase, or if the foot pronates in the late midstance or propulsive phases, the soleus fibres can stress and muscle strain occurs.
- Lateral knee compartment injury can be produced with overpronation. If you have lateral meniscal issues, you would want to open up and decompress the lateral compartment by varus wedging the foot. But, the knee joint is influenced by foot motion, the knee’s own axis of motion, and by hip motion. Therefore, 50% of patients do not respond to lateral wedging, but everyone seemed to be helped by some form of foot stability correction.
- Pes anserinus tendinitis/bursitis can be produced by overpronation. The 3 muscles that make up the pes anserinus attach into the proximal medial aspect of the anterior tibia for stabilization at foot contact of the knee. The three muscles are the sartorius, gracilis, and semitendinosus also called guy ropes. By their attachment, at foot strike, and it is primarily a running related injury, it stabilizes the anterior medial knee area which is stressed in the overpronation motion of excessive internal tibial rotation on the femur. It protects the anterior cruciate ligament which is trying to stop the anterior and medial displacement of the tibia on the femur from inside the knee. I especially see it in downhill running, where these medial knee structures have to stabilize a flexing knee at foot strike where the force can be 10 times body weight.
- Patellofemoral injuries can be produced by overpronation. The problem lies in the kneecap or patella not staying in its normal femoral groove, but sliding laterally thus irritating the medial aspect of the posterior surface of the patella. This lateral subluxation is helped with taping the patella slightly medially, bracing the patella to hold it more centered, strengthening the vastus medialis and external hip rotators, and stretching the very powerful vastus lateralis to weaken its pull laterally. With overpronation, sometimes just produced by the sport in a normal foot, 2 mechanisms can be to blame either fully or partially. If the overpronation causes the knee to assume a more valgus position of the tibia on the femur, this alignment causes the vastus lateralis to have more power pulling the patella laterally. If the overpronation simply produces more internal rotation of the tibia on the femur, the vastus lateralis is placed in tone, and the vastus medialis relaxed creating a dynamic muscle imbalance leading again to the lateral subluxation of the patella.
- Anterior Cruciate Injuries can be helped by pronation correction. I do not think that ACL injuries are caused by overpronation, but from our previous discussion of pes anserinus injuries, the anterior cruciate ligament functions to stop both anterior motion of the tibia on the femur and internal rotation of the tibia on the femur. When treating patients with ACL injuries, either conservatively or post operatively, custom orthotics or simply varus wedges that can control the internal rotation of the tibia on the femur can take a great deal of stress away from the ACL.
- Medial hamstring strains can be produced by overpronation. The medial hamstrings are the semimembranosus, attaching into the posterior medial aspect of the proximal tibia, and the semitendinosus, attaching into the anterior medial aspect of the proximal tibia. In normal function, the medial hamstrings are knee flexors and internal rotators of the tibia helping with foot pronation. However, with excessive foot pronation, the role of the semitendinosus as part of the pes anserinus must be to protect the anterior medial knee and stop the forward motion of the tibia. This repeated motion can cause strain of the medial hamstrings.
- Iliotibial band syndrome can be caused by a variety of abnormal motions, and one of them is overpronation. The Iliotibial Band is one of my most favorite structures. Its primary function is to protect the lateral hip and the lateral knee at foot strike. It is prone to get tight, making it easier to strain. It is a very common running injury and it does not take a lot to cause it to be overworked. Excessive pronation is only one motion that can irritate it, but probably the most publicized. As the femur internally rotates with excessive subtalar joint pronation, the tibia, where the iliotibial band attaches, internally rotates more. This motion of internal rotation of the tibia on the femur brings the iliotibial band anterior over two body landmarks. These landmarks are the greater trochanters around the hip area and the lateral femoral epicondyles at the knee. Women typically develop ITBS at the hips and men at the knees.
- Piriformis syndrome can be caused by overpronation. With walking and running, the piriformis is an external hip rotator. Therefore, excessive pronation which causes excessive internal hip rotation strains the piriformis muscle trying to decelerate that internal motion. The interesting and perplexing aspect of piriformis syndrome is how it can involve the sciatic nerve and cause neurological symptoms. The sciatic nerve can run under, over, or between the fibres of the piriformis. So many problems we treat have a neuropathic aspect because the sciatic nerve gets irritated. You can get classic sciatica symptoms, or just vague neuropathic symptoms.
Checklist of Pronation Produced Problems:
- First MPJ Pain
- Sesamoid Pain
- Bunions
- Second MPJ Pain
- Metatarsalgia
- Second Metatarsal Stress Fracture
- Morton’s Neuroma/Neuritis
- Hammertoes
- Intrinsic Muscle Strain
- Plantar Fasciitis
- Anterior Tibial Strains
- Sinus Tarsi Syndrome
- Cuboid Syndrome
- Lateral Ankle Impingement
- Posterior Tibial Strains
- Tarsal Tunnel Syndrome
- Peroneus Longus Strains
- Achilles Strains
- Tibial Stress Fractures
- Medial Soleus Strains
- Lateral Knee Compartment Pain
- Pes Anserinus Tendinitis/Bursitis
- Patellofemoral Joint Pain
- ACL support when injured
- Medial Hamstring Strains
- Iliotibial Band Strains
- Piriformis Syndrome
