Date: 22.01.2012
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Largely ignored unless they go wrong, our feet are
responsible for more than we might think. Making up one eighth of the human
body’s bones they are made up of 26 bones, 30 plus joints and are influenced by
10 major muscle tendons.
As your contact point with the ground, the adaptable nature of you feet ensures you have a smooth ride during locomotion and gait. Whatever the terrain, your feet allow you to traverse comfortably and efficiently during both walking and running, taking on any variations in their stride.
Common foot complaints
Foot and ankle dysfunction has been attributed to a large portion of the 35% of the population who experienced lower back pain (LBP). While other risk factors of LBP exist such as sedentary lifestyles and pathologies, the effect of foot and ankle dysfunction on the lumbar and sacral spine, pelvic and SIJ stability, hips and butt structures is profound.
Many of us do experience dysfunction of the foot and ankle, and are largely unaware of it until pain or referred injury occurs. For this reason it has now become mainstream practice for sports people such as runners to have their gait analysed by either fitness professionals, or specialist running shops.
Generally speaking a slow motion video will be taken at the foot and lower limb level, and any motion will be observed. It is common for runners to be prescribed a stability shoe with medial support. Approximately 70% of us over-pronate with excessive eversion at the ankle joint during gait, and in more extreme cases orthotic insoles may be prescribed.
With the new trend of natural running and fore to mid foot striking during the gait cycle the appropriateness of these stability shoes may be brought to question, and the perfect functioning of the foot and ankle may well become even more important for runners.
Some Common Foot Dysfunctions
Pes Planus is an under developed arch in the foot, characterized by an eversion of the foot and a collapsed arch. A wet footprint would show contact with the ground at the arch in the medial area of the footprint.
Pes Cavus is an excessively raised arch. During gait an overly high arch does not drop and the foot does not evert normally. A wet footprint would show a very narrow contact point connecting the toe and heel contact points.
Talocrural joint is responsible for joining the tibia and fibula bones to the talus. The talocrural joint allows for both plantar and dorsi flexion and since a major portion of the range of motion occurs about this hinge joint it is crucial that it functions properly. If there is limited motion about this joint, there will be referred consequences further up the kinetic chain.
Ankle impingement, as the name suggests occurs when soft tissue usually at the front or back of the ankle gets pinched during plantar or dorsi flexion. The resultant pain that is experienced certainly hinders the normal motion about the ankle during gait and an unnatural compensated gait cycle will be adopted.
Subtalar joint dysfunction where the talus meets the clacaneus can cause problems in terms of inversion and eversion – the rolling in and out of the foot. In contrast to the talocrural joint the subtalar joint has no role in plantar or dorsi flextion.
The midtarsal joint is responsible for rotation of the foot about a longitudinal axis (foot rolling in and out) and allows independence between the front and back of the foot. This in part contributes to inversion and eversion.
What happens when your feet don’t function correctly?
As suggested, when dysfunction is observed at the foot and ankle, the symptoms may well be referred further up at knee, hip, pelvis and spine. On striking the ground in walking it is normal for the foot to land slightly inverted, and as the body mass shifts over the foot eversion occurs.
Inversion allows the foot to adapt and mould to suit the terrain, and when it is time for ‘toe off’ eversion allows the foot to stiffen up into a rigid structure before relaxing again for next heel strike. If one or more parts of this sequence of small movements between joints are dysfunctional there will be repercussions up the kinetic chain.
Those with pes planus and pes cavus characteristics tend to evert and invert the foot excessively. Over 70% of people experience excessive calcaneal eversion and this is associated with increased tibial rotation. This puts added stress and misalignment on the knee joint and increases internal rotation of the thigh. The chain continues up to the hip joint, which can place the pelvis out of balance. Rotation and lateral tilt or Trendelenberg gait and the consequential stresses placed on the sacro-illiac joint (SIJ) and scoliosis of the spine can all result in referred injury.
Adaptation and Compensation
During normal gait it is essential for the foot to be stable at mid gait and when fully loaded. During this stance while the free leg swings through, the muscles responsible for core and pelvic stability require a stable platform in order to function properly. If excessive pronation or eversion presents itself, these muscles in particular the gluteus medius will be compromised and will not function efficiently. Exacerbated by long hours in a triple flexed position (knee, hip and spine flexion) at work or driving, the muscles become weak, and hypotonic – switched off. Clinically described as Trendelenberg gait, this abnormal pelvic rocking can be identified with video gait analysis and it is possible to identify this ‘switched off’ gluteus medius and pelvic instability.
The human body adapts very effectively to any demands imposed on it, and for this reason the compensatory role of the adductors, piriformis and tensor facial late may result in tightness in these areas. Increased pelvic movement as lateral, anterior and posterior tilt and in the transverse plane can also place excessive stress on the tissues supporting the SIJ causing inflammation, pain and SIJ dysfunction. Furthermore, increased anterior tilt exacerbates the lumbar-sacral angle and lumbar hyperlordosis. The resultant stress on the inter-vertebral disks, spinal nerves, facet joints and supporting muscles can present pain.
In Conclusion
Proper foot and ankle function is essential. Although largely neglected our feet affect the function of our entire body, and it is not until we experience pain or discomfort that we notice them. Getting your gait analysed could be one of the best decisions you could make. From the feet up, you can effectively perfect your posture and function and enhance not just your walking and running gait, but your every day activities and gym based exercises such as squatting, lunging and deadlifts.
By Nico Valla
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