Biomechanics and the Geriatric Patient

Dancing on the beach
Happy feet at any age

When considering older patients in any context it’s best to not fall into the trap of chronological age. There are many 70 year old individuals who are in better condition than their 40 year old counterparts. Physiological age should be the prime consideration. This is equally true for the geriatric biomechanical patient as for the surgical patient. There are no basic contraindications to the use of a controlling functional orthotic device if the patient is in a position to accept such control and the doctor is reasonably certain that some degree of success will be forthcoming.


However, there are certain considerations that must be taken into account when dealing with geriatric patients:


How should the patient be examined?


                The elderly individual whose biomechanical function has been pathological for years has had that much more time to deteriorate than the younger patient. The bones of the feet and legs may be functionally adapted or misshapen and the ranges of motion may be diminished. Under these circumstances they may only be able to approach their neutral position but never reach it. There may be other restrictive factors such as osteoarthritis in varying degrees. The elasticity of their tissues may be diminished and there may be some muscle shortages or contractures that may not reduce.


Therefore, examination should take into account these as well as other factors:

  1. Is there at least a total of 30 degrees of subtalar motion?
  2. Is there at least 10 degrees of ankle dorsiflexion?
  3. Is there a range of pronation and supination of the forefoot at the midtarsal joint?
  4. Is there adequate motion at the hips?

If the answer to these questions of affirmative then you have a good candidate for orthotic control.


What if there are limitations in these areas?


The greatest problem facing us relative to biomechanical control of the feet and legs is the reduction of the range of motion in the previously mentioned areas. Not only does this prevent the patient from reaching their neutral or optimal functioning position, but it robs them of their free mobility. They are forced to move into pathological functional positions in order to move properly. Therefore, in addition to obtaining raw data in the form of measurements, whether precisely quantitative or clinically qualitative, the practitioner must first evaluate their findings, correlate them with any x-rays obtained, and determine how the case will be managed.


How should the practitioner weigh the biomechanical factors in the geriatric patient?


In an elderly patient who is physiologically young and has good ranges of motion, the prime consideration is advanced bone adaptation due to pathological function. Treat as follows:

  1. Cast slightly pronated from neutral position
  2. Reduce the rearfoot control posting slightly
  3. Reduce all forefoot posting since it is more likely a forefoot supinatus opposed to a true forefoot varus


In an elderly patient who is not physiologically old but is affected by problems of old age such as mild arthritis of the limbs and back, the prime consideration is tolerance, also partial control. Treat as follows:

  1. As above (steps a through c), or consider reduced compressible posts
  2. Consider semi-flexible functional orthotics which give rearfoot control and have compressible posts


In an elderly patient who is physiologically as well as chronologically old, only the mildest form of control for the purposes of stability or accommodation to increase comfort should be used. Treat as follows:

  1. Pronate all casts or use weight bearing or semi-weight bearing casts.
  2. Use flexible orthotic devices with zero degree rearfoot posts or no posts
  3. Use accommodative mold of semi-soft consistency


What about the severe acquired forefoot deformity seen in the geriatric patient?


                This deformity is often the patient’s only major concern. The digital orthoses, if properly made and backed up with properly posted orthotics, can produce miraculous results in this type of patient.


What will the prognosis be for this type of patient?


                Time is our biggest enemy in this type of situation. The patient has had a lifetime to deteriorate and the damage cannot be undone. Therefore, with chronic conditions such as plantar keratomas, malaligned digits, arthritis and other problems, guard your prognosis. It should be fair at best. Acute conditions such as heel bursitis, neuritis, metatarsalgia and others respond well to treatment.


At all times go slowly. Give the older patient time to adjust and realign the bones and muscles. It may be ideal to use soft top covers and extensions. Employ appropriate physiotherapy modalities such a hydrotherapy and paraffin baths. Finally, notice that much of what has been stated in this article also applies to younger patients, thus physiology and not chronology should be the main guidepost. Paragon offers a wide selection of devices that can be customized to suite patients of any age. As always, our team is here to discuss and advise as necessary.

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Biomechanical and Postural Considerations/ Orthotic Treatment By Joe Coletta, PTA,