Orthotic devices come in many forms and can generally leave you feeling bewildered and lost in which way to turn for help. They are used to assist function and promote a biomechanical change and reduce pain. But how do you know if they are right for you? After all they range from £20 – £300.
Lets looks at this simply, your foot function is imperative as it is the first and only part of your body to make contact with the ground, add into the fact that when the foot hits the ground you have to contend with a ground reaction force. As a result you must ask, do you have the strength and function to control that load? If not it is likely you will run into trouble. At Achilles we pride ourselves on providing quality to our customers and use a RSscan which provides three dimensional feed back.
If you’re an active person the orthotic should be stable enough to effectively improve your mechanics for its purpose whilst contending with the ground reaction force. The ground reaction force is 6-7 times your body weight in certain muscle groups. It is important when having orthotics developed that you are not assessed statically, as your foot function from walking to running will vary greatly, therefore a static assessment would be pretty helpless for someone developing pain when they run, you will generally walk with your heel striking the floor first, however you may run with your toes hitting the floor first this providing a complete different finding in your mechanical assessment, therefore orthotics should be designed accordingly.
What is ground reaction force?
Newton’s 3rd Law of Motion states that “For every action there is an equal and opposite reaction.” According to that, when we walk or run, every time our foot lands, there is what is called a ‘Ground Reaction Force’ produced.
Nevertheless orthotics are used to facilitate rehabilitation and should not be used solely to expect change. In some cases where there is mechanical restriction for example if your big toes are hurting (Hallux ridigits or limitus) then yes this is an exception.
Functional Hallux Limitus– Your foot and big toe may look normal in both stance and non weight bearing examinations, during function the big toe fails to work normally ( dorsi flexion, or bending) due to bones packing closely and preventing the windlass mechanism. This can lead to big toe pain, the inside of your calf getting tight and calf strains along with multiple other issues.
Hallux Rigidis or stiff big toe is degenerative arthritis and stiffness due to bone spurs that affects the MTP joint at the base of the hallux (big toe). Early treatment for mild cases of hallux rigidus may include prescription foot orthotics, shoe modifications (to take the pressure off the toe and/or facilitate walking), specialised footwear (‘rocker-sole’ shoes), medications (anti-inflammatory drugs) or injection therapy (corticosteroids to reduce inflammation and pain). (Physiotherapy) programs may be recommended, although there is very limited evidence that they provide benefit for reducing pain and improving function of the joint
Mortons Neuroma – is an enlarged nerve that usually occurs in the third interspace, which is between the 3rdand 4thtoes. Hallux limitis or hallux valgus normally present with this condition. It is believed to occur due to a ligament above the plantar pedal nerve called the deep transverse metatarsal ligament which holds the metatarsals together and creates a ceiling for the nerve compartments. With each step, the ground pushes up on the enlarged nerve and the deep transverse metatarsal ligament and causes compression which irritates the nerve. Often symptoms will be burning, or pain in the foot when walking and running. An orthoticto correct mechanic and a metatarsal dome would be fitted to create more space for the nerve to allow it to settle down.
Plantar Fascia Pain – 10 % of runners report plantar fascia heel pain, there is bands of dense connective tissue that connects the heel to the toes and this stabilises the foot through a gait cycle. It acts very much like tendons and responds to load. It can become irritated with increased pronation ( foot rolling in) and this can causes hallux limitis ( stiff big toe when walking / running). Therefore anything that reduced pronation with offload the fascia. So an orthotic in this instance would aim to reduce pronation and improve big toe movement. If an orthotic inhibits these functions pain is likely to continue. Apart from orthotics and exercises, shockwave therapy has become the preferred management for this with results showing upto 92% success rates.
Anterior Knee pain – Does every one with anterior knee pain need and orthotic? No is simply the answer, people who dynamically over pronate are most likely to benefit. There is numerous causes of anterior knee pain, and an orthotic in this instance would be a adjunct to therapy, and should not be considered a cure in itself. Often weakness is present in the ankle and glutes. The knee becomes a culprit of what occurs at the hip and ankle so this should be addressed with any rehabilitation.
Tendinopathy – is a broad term encompassing painful conditions occurring in and around tendons in response to overuse, common area are achilles tendon, patellar tendon, and tibialis posterior tendon. Tendons typically respond negatively to a spike in training volume, essentially exceeding a capacity for the tendon to contend with. Tendons maybe be painful to touch and squeeze. Typically the foot will have a mechanical dysfunction, your big toe may be restricted (1st ray restriction), pronation may occur, or the heel strike may be very heavy. Tendinopathies is a complex issue and an orthotic would serve as an adjunct to the bigger treatment plan of tendinopathy. Shockwave Therapy is a useful alternative in the management of tendinopathies along with appropriate loading / exercise for the specific tendon.
Medial Tibial Stress Syndrome (MTSS) This is characterised by tenderness over the distal medial two thirds of the shinbone, the shin bone can be very painful. Pain will typically intensify with impact at the start of exercise, this will occur gradually with no history of trauma. It is believed to occur due to loading forces. It generally hurts in the mid third of the shin bone due to tension created on fascial attachment to the shin bone which is increased with pronation of the foot. Risk factors for developing this is increased exercise activity without prior conditioning, increased BMI, increased pronation, increased tibial loading ( shin bone) and increased vertical loading. Rehabilitation should be aimed at increasing the strength of the lateral rotators of this hip so it reduced pronation in the foot, strength training is imperative in the management of MTSS. Orthotics will assist in reducing pronation moments. It has become increasingly common to utilise a custom made orthotic for this purpose. Motion control trainers should be considered if you are suffering form this.
At Achilles Physio we have a 40m running track, we use an RS Gate scan machine which gives us the scope to assess your function and the need for orthotics whilst running, walking, golfing or what ever discipline you may require an assessment for. We offer initial assessment to assess function, this is capable of detecting the amount of Newtons (force) that is being distributed through your limbs whilst running, it will give a 3D representation of the pressures that occur during your gait cycle. This is an exciting piece of equipment that takes your experience of care to the next level. As a clinic we pride ourselves on quality, no matter which physio you see, you will receive excellent care that is evidence based and in your best interest.