Point-Counterpoint: Stretching: Is It Beneficial For Plantar Fasciitis?
The fibers that stretch in the posterior musculotendinous system are predominantly in the muscle. Tendon does not stretch well or easily although its compliance is alterable by some types of stretching. Likewise, the plantar fascia is not easily stretchable and I believe that efforts to stretch the plantar fascia may end up also acting on the intrinsic muscles and tendons. There is indirect evidence that this occurs clinically and I will discuss this further below.
While studies have attempted to determine the existence of an anatomical connection between the Achilles tendon and the plantar fascia, the mechanical linkage is not in question.12 They both have in common a connection to the calcaneus with actions that are in opposition. An Achilles tendon and calf muscle that are tight are going to place added strain on the plantar fascia.
What Harm Can Stretching Do?
Alfredson, a strong proponent of eccentric stretching and a major theorist of Achilles tendon injury, strongly warns against eccentric stretching for insertional Achilles tendinopathy.13 Alfredson considers the insertion point to be a weakened and vulnerable area when it is injured. I would suggest that the enthesopathy of plantar heel pain is another area where caution is advisable.
A 2005 study of flexor hallucis longus tendinopathy found that more than half of the study patients had prior therapy for plantar fasciopathy.14 The authors noted a close correlation of flexor hallucis longus tendinopathy with other areas of symptoms, particularly the plantar fascia. The conservative treatment group did not do well. A mainstay of their previous therapy was likely stretching of both the calf muscles and the plantar fascia. I conjecture that manual dorsiflexion of the toes, including the hallux, may have triggered the flexor hallucis longus tendinopathy.
I see this often in clinical practice. If you look for flexor hallucis longus tendinopathy in patients presenting with plantar fasciopathy, you will often find it in patients who have spent considerable efforts in “stretching” their plantar fascia by dorsiflexion of the toes and, in particular, the hallux.
Assessing The Different Forms Of Stretching
Stretching is not a warm-up. Stretching should follow exercise or after patients have warmed up. The best warm-up is to perform slower and gentler movements and exercise than you will be undertaking in your sport.
Static stretching may inhibit performance. Studies demonstrate a weakness and performance decrease following static stretching of the ankle plantarflexors.15,16 The decrease in performance may be due to neural inhibition rather than an alteration of muscle and tendon mechanical properties. This is one reason why pre-exercise static stretching has gone out of vogue.
Is stretching always appropriate? Stretching is a reasonable approach to an early, mild to moderately painful presentation of plantar fasciitis. It is not appropriate as the sole treatment for chronic plantar fasciitis.
Stretching is not as simple an undertaking as it seems. There is static and dynamic (formerly ballistic) stretching, and there is active and passive stretching. In static stretching, the body segments are not moving while in dynamic stretching, there is motion. In active stretching, the muscles are contracting. In passive stretching, the muscle contractions are minimized.
Over the years, different types of stretching have gone in and out of fashion. Coaches of the 1970s recommended ballistic, active and dynamic stretching. Physicians originally condemned ballistic stretching only for that stretching style to come back again in a more sophisticated manner. Different stretches have uses for different problems at different stages of training. A combination of stretch types is likely to be more useful than only one specific stretch type.
The first person to suggest that over-stretching could lead to problems was Schuster. While puzzling over survey data indicating that more stretching led to more injury, Schuster suggested that over-stretching might lead to a higher incidence of injury.17 More recently, D’Amico has suggested that initial treatment of plantar fasciitis should stop all stretching.18 D’Amico also suggested using a shoe with a rigid shank and a heel lift.