LOWER LIMB BIOMECHANICS
“The Greatest Engineering Device in the World”, was how Leonardo Da Vinci described the foot.
By looking at the engineering of the lower limbs, we can assess where there are problems in foot function.
The sole purpose of walking or running is to transport the body safely and efficiently across the ground, on the level, uphill and downhill with minimal expenditure of energy.
The complex interaction of all 38 muscles and tendons, 37 joints and 26 bones which make up the foot must function in harmony so that we can stand, walk and run in an effective and efficient fashion. When our feet don’t function correctly, it creates a whole host of problems which are not just related to the feet.
Many of the muscles in the foot have attachments in the leg. Even if only a small fault exists in the foot, pain can result within the leg and higher up particularly in the lower back.
Most people have some form of foot fault but may not realise it until symptoms start to appear. For example a bunion begins to develop, or pain starts or becomes worse.
If you play sport, you may have a recurring injury or pain that you may not immediately associate as being a foot problem. The onset of pain may not even be from your feet. Pain in the knees, hips and lower back can quite often be attributed to the feet.
But before we can advise on any treatment, we have to properly assess what is happening to the feet and legs. Only by properly assessing the lower limbs can a treatment plan be devised.
The Next Step
This involves a full lower limb assessment. Various measurements are taken with the patient lying down (non-weight bearing) and again, standing up (weight bearing). The range and quality of motion in the lower limbs is also assessed, along with muscle tone.
Special equipment is used to help us with the assessment, including a treadmill with a camera attached. This helps us to analyse your gait cycle (the way you are walking).
If necessary, functional foot orthoses are prescribed. Advice on exercises and other helpful treatments will be given if this is appropriate.
Functional foot orthoses are a functional device, not to be confused with an arch support, which props up your arch. The orthoses fit into your shoes. Their purpose is to retime the motion of the foot during the various stages of weight bearing, allowing the foot to lie in the correct position at the correct time. This also allows the pressure taken by your foot to be more correctly distributed.
To help us have these devices made, we take a scan of each foot. This replaces the need to cast your feet in Plaster of Paris and is a far more accurate way of collecting the data.
The images of your feet, along with the prescription, are sent by Email to the laboratory, where your orthotics will be made to precisely fit your feet.
The materials that orthotics are made from now are very advanced. They are extremely strong but are also thin and flexible. They fit in to most appropriate footwear.
Wearing appropriate footwear is very important and advice on suitable footwear for everyday and for sports is available.
Made-to-measure and made to order footwear can be ordered if required.
So what conditions can Functional Foot Orthoses help?
Ball of foot pain (Metatarsalgia)
What is it? A burning pain usually located under the 2nd, 3rd and 4th metatarsal heads. Sometimes people describe a feeling like 'walking on pebbles'.
What causes it? The foot rolling inward too much (overpronation), ill fitting shoes or ladies high heeled shoes.
Treatment....... Biomechanical research has shown that if the pain occurs in normal well fitting shoes, the cause is over pronation. This is the collapsing of the arches and rolling inward of the ankles. Wearing foot orthotics (onsoles) can be very effective in relieving this pain. Often insoles will have a small dome or pad, but in our experience most people find that this increases the 'walking on pebbles' pain and we prefer either Bespoke Orthotics, with the appropriate padding or the Precision Black ready made orthotic. Both of these options provide a superior control to teh mid part of the foot and takes the pressure away from the painful area.
Very few people are born with bunions. They are usually caused by stress placed on the big toe joint making the muscles have a bowstring effect. We inherit the foot type and shape and after a number of years of walking, the bunion will start to appear.
By taking the stress away from the big toe joint and allowing the foot to function properly, we can help slow down the bunion.
This can be a very painful condition. It occurs because as the foot flattens, the ligaments and muscles which attach to the heel can be stretched too much. It can be particularly painful first thing in the morning when you get out of bed and when walking after resting your foot. Sometimes a heel spur can develop. This is a small piece of bone which grows onto the bottom of the heel to try and keep the soft tissues from tearing.
By assessing the way the feet are working, the strain can be taken
away from this area, relieving the pain.
Ankle and Achilles Tendon Injuries
These injuries can keep recurring. Often they are due to an underlying biomechanical problem. Once the problem has been identified, the aim is to take the stress away from over-worked joints which have been asked to provide excessive movements.
The cause of pain in the shins is varied. One of the most common is Medial Tibial Stress Syndrome. The pain is associated with activity and it is usually triggered by an increase or change in the activity (changing the running surface or increasing mileage, for example). It can be caused by the foot over-pronating and the muscles attached to the tibia overstretching. It is important not to work through the pain, but to seek advice.
Lower Back Pain and Knee Pain
These problems can often be associated with poor foot function.
If the foot is collapsing inwards (over -pronating) it will take the knee with it. The pelvis can also end up out of alignment, particularly if one foot collapses more than the other. The result can be as though one leg is shorter than the other and spinal problems may occur.
Growing Pains (Paediatric Leg Pains)
Children’s bone structures are more flexible and mobile than adults. High activity on their feet can cause the muscles to over-work and may cause pain later. Many children wake during the night, crying or complaining of leg pains.
If the pains are severe, it may be worthwhile considering some extra support by means of a suitable orthotic which can help to assist with the alignment of young growing bones and greatly reduce muscle strain.
Heel Pain ( Sever’s Condition)
This can occur in children between 8-14 years and is more common in boys who are involved in running-related sports, particularly over hard surfaces.
This is a condition where the bony protrusion below the knee (called the tibial tuberosity) becomes inflamed. It mainly affects boys between 10 – 16 years old. It usually coincides with a growth spurt.
Strapping and the use of orthotics can help to alleviate the symptoms and provide a good support.
Functional foot orthoses are not a ‘cure all’ for every condition, but by addressing the problem and not the symptoms we can help alleviate many problems.