Plantar fasciitis (PF) affects nearly 10% of the general population(1). This lingering and painful foot problem can be devastating to a hiker. Hikers often feel the pain along the middle border of the calcaneus or heel bone, which is the origin attachment site of the plantar fascia (see figure 1).
Figure 1: Plantar fasciitis pain areas (2)
The plantar fascia is a tough sheet of connective tissue that lies along the bottom of the foot. It acts as a structural support to the foot’s arch and functions to maintain rigidity of the foot when pushing off from a step.
Because the plantar fascia is a non-contractile tissue, meaning it doesn’t function and grow like a muscle, it needs a limited blood supply to stay viable. This lack of blood and associated nutrients may be one reason that the syndrome takes so long to heal. Once inflammation sets in, pain tends to linger for weeks and even months. Hikers may feel pain first thing in the morning when stepping out of bed or out of the tent. The pain may improve with walking throughout the day but may return after long periods of sitting.
Causes and risk factors
There’s no official cause of PF, but there are associated risk factors. Like most athletic injuries, PF is attributed to training errors, such as:
· A spike in training distance;
· Changing environment to incorporate hill climbing;
· Changing terrain such as moving from paved or soft paths to rocky trails;
· A sudden increase in training load such as carrying a heavy pack daily after only training with the pack a few days per week;
· A change in footwear – especially a move to zero-drop shoes;
· Ignoring the footwear break-in period;
· Worn out footwear;
· Not incorporating enough recovery.
Other risk factors include obesity or a high body mass index as seen in heavier athletes such as football linemen or weightlifters.
Treatment
Because the pain of PF appears to improve with walking as the day goes on, most treatment approaches center around stretching the plantar fascia. This treatment also incorporates sleeping in a boot or stretching sock to prevent the fascia from retracting during the night. The stretching recommendations often extend to the calf muscles as well.
The curious thing is that stretching and strain at the origin site presumably caused the inflammation and trauma in the first place. Therefore, is further pulling on the site really the best approach? Remember, the plantar fascia is non-contractile tissue. Thus, it’s difficult to lengthen this tough connective membrane through periodic or even sustained stretching.
The same goes for various methods of fascial massage. Recommendations include using foam rollers, hiking poles, or lacrosse or tennis balls to massage the area and loosen the fascia. Yet, this tough tissue is inherently resistant to stretch, and deep massage to the origin site only inflicts further mechanical trauma to an already inflamed area.
There are also many treatment modalities employed to remedy PF. Ice, ultrasound, laser, pneumatic shock, and radiofrequency are a few of the modes of treatment. The only one with compelling evidence of efficacy is extracorporeal shock wave therapy (ESWT). Even when compared to steroid injection therapy, ESWT showed better results(2).
For many, the only treatment that works is to stop hiking. Sometimes the syndrome becomes so bad that complete rest is the only way the body can heal itself.
4 steps to stave off plantar fasciitis
1) The best way to prevent PF is to avoid training errors. That means planning your training to allow for gradual changes in terrain and load. Work up to longer hikes and don't suddenly go from paved city sidewalks to rugged trails.
2) Wear proper, supportive shoes. Most outfitters will have experts in helping you choose a shoe that works for you. If you decide on a zero-drop trail running shoe, break it in slowly. Wear it for short periods of time each day and slowly lengthen the amount of time you spend in them.
3) Get enough rest and adequate nutrition to support recovery. Feet get forgotten when we're planning recovery. Don't forget that they need adequate rest so if you've had a big hike, maybe take the next day off and put your feet up!
4) Another means of prevention may be strengthening the muscles of the feet.
A recent (December 2019) research review highlights the muscle weakness in the feet of those who suffer from PF(1). Whether the weakness contributed to the development of PF, or is a secondary issue due to pain and dysfunction, is yet to be determined. However, neither stretching nor modalities address the weakness.
One hypothesis is that weakness in the muscles of the feet means the plantar fascia must play an excessive role in supporting the arch. Therefore, before planning an extended hike or change in training, you should include exercises for the feet in your training schedule. Exercises should address the long flexors of the toes and the intrinsic muscles that support the arch. As always, consult with your physician before starting any exercise program.
Exercises for strengthening the feet
The towel scrunch exercise
The cup exercise
The foot doming exercise
References
1. J Orthop Sports Phys Ther. 2019;49(12):925-933