In plantar fasciitis and many cases of Achilles tendonitis, part of the treatment regimen usually includes stretching. Stretching helps to increase elasticity of tissues which decreases the tearing and pulling of these tissues that causes pain and injury. There are a couple of instances when stretching isn't a good idea and there are even some more controversial ideas about when stretching isn't good.
When we talk about stretching in podiatry, we are most often referring to the Achilles tendon and plantar fascia. In plantar fasciitis, the ligament has begun to be can be functionally shorter when non-weight bearing and with over use develops scar tissue. This all adds up to a piece of tissue that cannot withstand the pull of day to day walking. Stretching helps to increase the elasticity in this area, allowing your foot to better accept and transfer the weight without having the plantar fascia pull and tug on the heel bone. In extreme and unaddressed cases of plantar fascia, an injury can occur in which one or a couple of plantar fascia bands rupture (or completely tear) at the insertion on the heel bone. Stretching in this instance causes increased pain and inflammation. If this injury occurs, it is best to rest the foot in a neutral position with the heel at 90 degrees. This allows the fascia to heal in a length that is more functional and less likely to tear in the future.
In conditions of the Achilles tendon, there are a couple of instances where stretching isn't a good idea. In one case, similarly to the plantar fascia, the Achilles tendon can rupture. These injuries present as an initial pop of pain, but the pain subsides quickly. If there is weakness in an area, stretching will only further encourage that weakness. This is vitally important in Achilles tendon ruptures, as if this injury is stretched, it increases the distance between the two torn ends of tendon and makes future healing difficult and a much longer process as the tendon will have to be repaired and slowly stretched back to a functional position once healed.
Stretching an Achilles tendon issue when there is the presence of a bone spur on the heel can cause increased pain and irritation to this bone spur and the tendon. Some believe that the act of repeated stretching can actually damage the tendon as it rubs over the bone and can cause future injury or weakness in the tendon.
Another instance where stretching is thought to not be a good idea, or rather where a bit of equinus (pointed toe) is beneficial is in certain athletics and dance. While evaluating patients' motion, we compare to a 'normal' range of motion at the ankle which helps to normally propel through your gait (walking). However, in professional ballet dancers and professionals in track, this slight decrease in motion actually helps them to jump higher or point their toe while dancing better.
If you aren't sure if you should be stretching or not, come visit one of our doctors and discuss your concerns!