Here at The Sole Clinic, we see a fair share of people for heel pain. Most people with heel pain suffer from this condition Plantar Fasciitis, which mean inflammation of the plantar fascia at the sole of the foot. However, not all painful heels have ongoing long-term inflammation, hence it’s now commonly termed as plantar fasciopathy or fasciosis. However, most still stick with the term plantar fasciitis for convenience sake.
There are plenty of different factors that lead on to plantar fasciitis that need to be taken into consideration. It is a condition that can affect both the high level athlete and the sedentary housewife, but the underlying causes could be very different. It is also highly associated with people with both high (pes cavus) and low foot arches (pes planus). Here again, the underlying mechanisms on why it causes pain in both the high and low foot arches are very different.
Therefore, plantar fasciitis is not an easy condition to treat effectively.
In fact, the best clinical reseach evidence suggest that plantar fascia stretching and using shoe inserts are only effective for 60% of the population. 40% of them continue to have symptoms and pain 2 years after diagnosis. More effective treatment are warranted!
I have recently came across this research paper that supports the use of high-load strength training for the treatment of plantar fasciitis. Let me summarize the findings of the study:
- Randomized, controlled trial
- 48 patients (> 18 years old), randomized into strength-training and control group
- had heel pain for more than 3 months (less likely to be predominantly inflammatory)
- has verified thickening of the plantar fascia as verified with diagnostic ultrasonography
- has pain on pressure on the heel where the plantar fascia is connected to
- nil previous heel surgery, steroid injection to the heel for the last 6 months, systemic diseases
A: Strength training group
- Calf strengthening exercises with towel to place the big toe into extension (‘windlass’ mechanism)
- 3sec concentric (going up), pause at the top for 2sec, then 3 sec eccentric (coming down)
- 3 sets of 12 RM (repetition max was pre-determined)
- loading was done via backpack with weights
- load progression every 2 weeks, simultaneously increased to 4 sets of 10 RM, 5 sets of 8 RM, etc
- for those not strong enough to perform exercise with good quality, to start with bilateral feet
B: Plantar-specific stretching (control) group
- ankle dorsiflexion + big toe extension: 10sec x10times, 3 times per day
- to feel for the plantar fascia tension during the stretch
- perform on both feet if both affected
Both groups were provided with gel heel cushions and patient information sheet:
There was follow up to ensure that the exercises were performed correctly for both groups.
Result of the study:
The significant finding in this study is that Group A (high load strength training) performed significantly better at 3 months follow-up than Group B (control group) in terms of pain and function as measured by Foot Function Index, a self-reported questionnaire that is valid and reliable to determine clinical changes in foot pain and function. However, Group B (control group) did sufficiently well eventually (slowly but surely) and both groups did equally well at the end of 12 months.
What we do not know, or cannot conclude from this study:
- How compliant were the subjects? Compliance is usually a problem as most people tend to reduce/stop their exercises after experiencing significant improvements. Therefore, the final outcome may not be an accurate representation of their final pain and function score if every subject were to be 100% compliant.
- What can we do for those who fail treatment? Research suggest that after a trial of failed conservative therapy, Shock Wave Therapy should be considered.
- Why didn’t the researcher control for people with different foot arch heights?
What I think we should be doing after reading this research article:
This is definitely a great new way to rehabilitate plantar fasciitis because it seems that the time taken to reduce the pain and improve one’s function is so much quicker! I will definitely consider this intervention for all those who fit the bill. However, I will prefer a multi-prong approach. This approach includes assessment of the foot arches and also consider the rest of the lower limb musculature that will affect pronation. As the current understanding behind the mechanisms behind plantar fasciitis pain is different for those with high and low foot arches, insole prescription should also be considered in the treatment of plantar fasciitis.
I hope that researchers will continue to conduct clinical trials in this area as this is an extremely common and problematic condition that will affect us because we need to walk every day!