Cath Lab Digest

   Rome and Brown reported a reduction in postural sway after four weeks of wearing prefabricated functional orthotics with a 4-degree rearfoot wedge.¹⁷ The study focused on 50 asymptomatic patients with diagnosed excessive foot pronation. The study authors concluded the use of orthotic devices may have improved postural control by stabilizing the rearfoot and maintaining balance as a result. By the same argument, the benefits of limiting excessive foot pronation may contribute to effective control of internal rotation of the tibia and thereby reduce counter-rotatory motion at the knee and lower leg, and maintain balance.

   Hertel and colleagues found that medially posted rearfoot orthotics enhanced postural control by significantly decreasing the frontal plane center of pressure length and velocity in healthy participants in comparison with footwear only.¹⁸

   Orteza and colleagues, as well as Guskiewicz and Perrin, found that molded subtalar neutral orthotics improved balance and caused a decrease in pain by reducing the magnitude of postural sway in various balance tasks in participants diagnosed with acute lateral ankle sprains.^19,20

   Percy and Menz demonstrated that foot orthoses had no significant beneficial or detrimental effect on postural stability in asymptomatic professional soccer players.²¹ Stude and Brink concluded that wearing custom-made foot orthoses for six weeks has a positive influence on balance ability and proprioception in experienced golfers.²²

What Are The Clinical And Research Implications?

This body of research has provided new insights into the potential benefits of foot orthoses and insoles, insights not previously recognized by most clinicians. Traditionally, foot orthotic therapy has always focused on improvement of function based upon correction of alignment of specific segments of the lower extremity. Indeed, foot orthotic therapy has produced reliable treatment outcomes for a myriad of musculoskeletal pathologies yet the mechanism of this therapy may not be what we always thought.

   Today, we must evaluate foot orthoses, insoles and footwear in terms of their potential effects on neuromuscular function of the lower extremity. Unfortunately, we do not have enough information to make reliable recommendations about prescription criteria for foot orthoses and their expected effects on neuromotor control. However, we do know certain aspects of foot orthoses therapy that may be beneficial.

   Custom molded orthoses will probably enhance recovery from acute ankle sprains and will also improve postural control in patients with chronic ankle instability. In general, devices that are custom molded tend to work better than prefabricated devices but this has not been conclusively proven.

   It is tempting to assume that the positive effects of foot orthoses on improving balance and postural control in patients with ankle sprains could also translate into potential benefits for other populations at risk for catastrophic falls. Elderly patients and patients with diabetic sensorimotor neuropathy not only have an increased risk of falls but also have poor postural control, which may improve with foot orthotic therapy. No studies have been published showing that foot orthoses will actually reduce the frequency of falls in these populations yet the link between postural control and falls would lead one to have some confidence in this treatment option.

   Traditional podiatric foot orthoses do not use textured topcovers or have noise-enhancing properties such as those used in previously cited research. However, one could certainly modify the standard orthotic prescription based upon a desired effect of improving sensory feedback from the foot.