Secrets To Biomechanical Considerations In Static Stance

Guest Clinical Editor: Nicholas Sol, DPM, CPed

   If a patient has a flexible collapsing midfoot in static stance, Dr. Borgia says one can assume the patient has shortened posterior musculature (i.e. equinus). This leads to a shorter stride, according to Dr. Borgia, and it explains why the posterior leg muscles fatigue faster than if the foot were more arched. Dynamically, the foot will not flow from heel to toe and Dr. Borgia says this alters a patient’s gait accordingly as it takes the patient more steps to get from one point to another.

   This effect leads to an increased risk of symptomatology, according to Dr. Borgia. The forces of weightbearing in a normal foot would translate through the osseous structures with the windlass effect in motion. Dr. Borgia says the windlass effect provides a stable push-off, permitting the peroneal longus to plantarflex the first ray. He notes this effect stabilizes the subtalar joint and equalizes forces throughout the anatomical trabecular patterns of the foot.

   However, Dr. Stern says the pathomechanics of static stance should not have much of an effect on the biomechanics of dynamic gait.

    “Chronic use of the muscles to control balance in static stance should not affect their function and use in dynamic gait unless patients develop some kind of tendon problem like posterior tibial tendonitis,” contends Dr. Stern.

   Q: In your experience, what are the most common pathomechanics associated with static stance?

   A: Dr. Sol says it is common for patients to have joint stiffness, which often leads to secondary complaints associated with compensatory gait mechanics. When patients have stiffness in one lower extremity, Dr. Sol says they will typically compensate with a decreased support phase and increased swing phase in the symptomatic lower extremity and a correspondingly longer support phase in the opposite lower extremity. He notes this leads to relative overuse of the asymptomatic limb. These patients frequently present with unilateral pain in the overused limb and Dr. Sol says he often winds up treating the contralateral limb.

   When it comes to static stance pathomechanics, Dr. Borgia commonly notes complaints secondary to a collapsing arch. He says these complaints may evolve into posterior tibial tendon dysfunction, plantar fasciitis or Achilles tendonitis, which may lead to degenerative joint disease of the subtalar joint complex if left untreated.

   Static stance can vary depending on a patient’s occupation and different types of shoes can affect stance, according to Dr. Stern. For example, when patients who work on automotive assembly lines present to his office, Dr. Stern typically sees heel pain syndromes beyond just plantar fasciitis. He also sees heel bursitis, which patients experience when they are wearing hard-soled shoes and standing in place. Posterior tibial tendonitis and subsequent chronic posterior tibial tendon dysfunction (PTTD) are also problematic in patients who work on assembly lines. Dr. Stern says these conditions are caused by chronic use of the hard-soled shoes and compensations for trying to control the stability of the foot in static stance.

   When treating patients who work as greeters at a casino and wear heels, Dr. Stern sees some heel pain but less than he sees in an auto worker. He adds that he also sees some posterior tibial tendonitis in these patients. However, in Dr. Stern’s experience, the most common presentation in casino greeters is metatarsalgia, including neuroma-like symptoms and capsulitis, especially on the second MPJ.

   Q: What specific orthotic modifications do you incorporate for patients who spend a significant portion of weightbearing time in static stance?

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