Can Flat Feet Cause Knee and Lower Back Pain?
Flat feet may contribute to knee or lower back pain in some people, but they are not always a cause. Flat feet, or mechanically termed overpronation or overpronated feet, is a postural alignment of the feet where the arch is lower than normal. The heel sits towards the outer side in a valgus position, and the toes point towards the outside of the feet when looked at from behind. This combination of collapse in a multi-plane manner is known as flat feet.
Some people may normally have flat feet due to their genetics, whereas other people may have them due to mechanical dysfunction, known as pathological flat feet. Whilst people often present with foot pain related to pathological flat feet, having flat feet has generally been attributed to causing knee and lower back pain due to the internal rotation of the tibia as a result of flat feet, and resultant lumbar lordosis, where your core muscles do not engage very well due to internal hip rotation and knee rotation.
Signs your foot mechanics may be contributing. If you find that when you are standing for prolonged periods of more than 20 to 30 minutes you start developing pain in your hips, knees, and lower back, or general fatigue of your legs, then underlying foot posture and gait may be the reason for this. The inefficiency of flat feet in supporting your feet from the ground upwards may result in these vague symptoms that are not due to any injury or any other causative factor.
How can foot position affect the legs and spine?
Normal pronation during gait involves slight flattening of the arch to absorb shock. But if the medial structures of the feet are lax or loose because of genetics, due to hypermobility syndrome, or because there has been failure over time due to increased weight, stresses, or injuries to the medial ligament structures, then the flat feet will become pathological. The resultant rotation of the lower legs and the hips will result in symptoms.
Can flat feet contribute to knee pain?
Flat feet can result in internal tibial rotation. It could cause dysfunction of the patella, where during climbing stairs, squatting, or walking, the patella subluxes laterally and causes irritation or a condition called chondromalacia patellae. Furthermore, you may get increased lateral knee wear due to the general valgus composition of the knee due to flat feet.
Can flat feet contribute to lower back pain?
Because of internal hip rotation and internal leg rotation overall as a result of flat feet, you lose the support from the core muscles engaging in the lower spine, resulting in lower lordosis. Essentially, you do not engage your core muscles. This results in impingement of the facet joints and sometimes nerves, causing lower back pain.
When flat feet might not be the cause
Sometimes there are other conditions which are truly inflammatory — rheumatological conditions, osteoarthritis — which may be causing your symptoms and are not related to mechanical dysfunction resulting from flat feet.
Also check: Causes of Flat Feet
How a whole chain assessment works.
We perform a gait analysis, a posture analysis, and an isometric strength analysis of your lower limbs. We look at normal range of motion and stability of your lower chain. We look at how your feet, knees, hips, and lower back all work together during the gait cycle to make that assessment. Sometimes video technology and 3D technology are used to assess this.
Treatment when foot mechanics are contributing.
Most people will have a mixture of footwear adaptation with physiotherapy to build strength if there is muscle weakness, as well as insoles and orthotics to support your arches and feet, to stabilise your knee and reduce the momentum change when walking during the dynamic phase of gait.
Which exercises may help?
Exercises that involve stretching your calf muscles or stretching your posterior group, such as your hamstrings, could help straighten things up. Intrinsic foot exercises, like picking a towel from the floor, can result in increasing your arch strength.
Which specialist should you see?
You should see a podiatrist who specialises in gait analysis, which is available at the London Foot and Ankle Surgery. They will perform a full musculoskeletal assessment as well as gait analysis.
Can flat feet cause pain in only one knee?
Yes, occasionally only one flat foot is worse on one side, resulting in knee pain on one side. You will often find that pain starts on one side and can develop in both knees.
Frequently asked question
If you look in the mirror and note that your arches are low and your toes point outwards, then you are more likely to overpronate.
It depends very much on your fit. Some people can fit into clothes that are off the shelf and others cannot — it is very similar. Some people get decent alignment with off-the-shelf orthotics. However, bespoke orthotics are generally more comfortable, fit into a greater variety of shoes, and last longer.
Generally, just having a low arch with no pain does not require treatment. However, it is sometimes difficult to ascertain long-term issues, especially when you have severe flat feet. An assessment by a clinician can help you to establish whether these are beyond normal limits.