Many chiropractors fit every patient with orthotics. They reason to great lengths that orthotics improve global proprioception and muscle activation. Therefore, all patients with diagnoses ranging from headaches to hip impingement can benefit from custom orthotics.
Current literature supports the need to match the right treatment to the right patient at the right time. Providing the same management to every patient regardless of condition is not supported by evidence-based practice. However, there is merit in the use of orthotics as a component of many management protocols.
Do orthotics “improve” muscle activation and stabilization throughout the body?
Research supports the notion that orthotics change muscle activation as measured by EMG studies. Providers should be cautioned that increased muscle activation does not always lead to improved proprioception or stability. The use of orthotics will change the muscles used in ambulation. For example, the use of a heel lift will increase gastroc, quadriceps, and lumbar erector activation. That does not make the use of heel lifts a valuable tool for improving core stability. Shoes and orthotics will decrease proprioceptive input by shielding feet from the ground. Thick-soled shoes and new orthotics separate the foot from the ground and change proprioception and motor response leading to increased activation of muscles. However, does this mean we have improvedproprioception or muscle activation?
When should providers use orthotics?
For example, when we take a closer look at posterior tibial tendon dysfunction (PTTD), we see a trend in the use of orthotics. Arch supports and orthotics are management mainstays for PTTD but have shown varying degrees of success. (1,2) One purpose of orthotics is to correct “flexible” deformities, i.e., maintain the medial arch, alter the velocity of pronation, and correct rear foot position, thus decreasing stress on the posterior tibial tendon. (3,4) Orthotics may help patients in the early stages of PTTD but may be less beneficial once the foot has lost stability or has developed a rigid deformity. (3) Studies have shown that for unstable feet, orthotics do not consistently improve alignment or gliding resistance of the posterior tibialis. (3,5) Once the foot has lost the ability to absorb shock and lock into supination—increasing muscle activation with an orthotic is no longer advantageous.
The evidence supports the use of orthotics for many foot, ankle, and hip complaints. Evidence-based chiropractors use custom orthotics for those patients requiring structural assistance in their recovery for many conditions. Patients who have pes planus or other non-reversible structural abnormalities may require long-term intervention with orthoses.
Cliff Atwell, B.S., D.C.