Point-Counterpoint: Stretching: Is It Beneficial For Plantar Fasciitis?
Offering pertinent biomechanical insights, this author examines the positive effects of stretching for plantar heel pain and the potential consequences of equinus.
By Lisa M. Schoene, DPM, ATC, FACFAS
Plantar fasciitis is probably the most common condition that the podiatric physician treats. We all have a myriad of treatment regimens and protocols that ultimately get our patients back on their feet.
Usually, we suggest stretching of the gastrocnemius and soleus muscles very matter of factly. We know that these two muscles distally form the Achilles tendon and that tendon expands around the posterior aspect of the calcaneus to join into the plantar fascia. The plantar fascia or plantar aponeurosis is a thick, fibrous band made of collagen tissues that have a tensile strength of 7,000 pounds per square inch within the central portion.
The fascia splits into three bands: the medial, central and lateral. The medial portion is thinner, originates from the flexor retinaculum and the medial calcaneal tubercle, and blends together with the central portion. The central portion, which is the thickest portion, is triangular in shape as it fans outward and into its distal deep and superficial layers. The deep layer attaches into the flexor tendons of each toe and helps to maintain the fat pads and plantar plates. The superficial layer merges with the transverse metatarsal ligaments. The lateral band originates from the smaller lateral tubercle, covering the abductor digiti minimi muscle and then inserting into the proximal and plantar surface of the fifth metatarsal. Under ultrasound inspection, the medial and central bands normally measure on average 2.5 to 2.7 mm thick from dorsal to plantar, and the lateral band should measure about 1.7 to 1.9 mm thick.
Due to the proximal attachments into the Achilles tendon, it would make sense that calf stretching both with the knee straight and with the knee bent would be an important part of the treatment protocol. Stretching will lessen the strain or pull into slips of the plantar fascia band from proximal to distal.
Understanding The Potential Impact Of Equinus
Looking at the anatomy, we know that a tight gastrocnemius and/or soleus muscle will result in a loss of dorsiflexion range of motion at the ankle joint. Tightness that predominates with the knee straight would suggest the gastrocnemius is tight whereas tightness with the knee bent would indicate that the soleus is the culprit. Either way, we typically define this as equinus.
There are many etiologies of equinus. These include spastic equinus, like one would see with cerebral palsy or high muscle tone issues, congenitally short musculature, prolonged casting, limb length discrepancies, a plantarflexed forefoot deformity, excessive use of high heels, lack of stretching, and/or general muscle weakness. Ultimately, partial or fully compensated equinus will produce some untoward effects within the foot and/or up the kinetic chain. When compensation occurs, it has to affect another area of the body.
The definition of “compensation” is a good thing to review since we treat many of the maladies it causes. The definition of compensation is an abnormal change of structure, position or function of one body part or joint in the attempt to neutralize the effects of improper deviations, positions, functions of another body part or joint. Given the profound nature of compensation, the true work of the thoughtful podiatrist can therefore change everything from head to toe. What happens “to,” “from” or “within” the foot will ultimately affect something else in the body. What will happen? Will that compensation go distally or proximally?
While discussing compensation patterns, there are other factors that may impede or enhance the situation. These factors are: ligamentous laxity, which allows joints to have much more mobility than they should; improper shoe gear such as unsupportive shoes; and even suprastructure issues, such as genu valgum, malicious malalignment syndrome, poor pelvic excursion, structural tibial and/or femoral rotational issues. The compensations along with any of these issues will unfortunately occur up and down the kinetic chain for all to see.