High-load strength training improves outcome in patients with plantar fasciitis: A randomized controlled trial with 12-month follow-up. Scand J Med Sci Sports. 2014 Aug 21. Rathleff MS1, Mølgaard CM, Fredberg U, Kaalund S, Andersen KB, Jensen TT, Aaskov S, Olesen JL.
The aim of this study was to investigate the effectiveness of shoe inserts and plantar fascia-specific stretching vs shoe inserts and high-load strength training in patients with plantar fasciitis. Forty-eight patients with ultrasonography-verified plantar fasciitis were randomized to shoe inserts and daily plantar-specific stretching (the stretch group) or shoe inserts and high-load progressive strength training (the strength group) performed every second day. High-load strength training consisted of unilateral heel raises with a towel inserted under the toes. Primary outcome was the foot function index (FFI) at 3 months. Additional follow-ups were performed at 1, 6, and 12 months. At the primary endpoint, at 3 months, the strength group had a FFI that was 29 points lower [95% confidence interval (CI): 6-52, P = 0.016] compared with the stretch group. At 1, 6, and 12 months, there were no differences between groups (P > 0.34). At 12 months, the FFI was 22 points (95% CI: 9-36) in the strength group and 16 points (95% CI: 0-32) in the stretch group. There were no differences in any of the secondary outcomes. A simple progressive exercise protocol, performed every second day, resulted in superior self-reported outcome after 3 months compared with plantar-specific stretching. High-load strength training may aid in a quicker reduction in pain and improvements in function.
Great paper! I have been stressing importance of strength training in place of and in addition to stretch (depending on whether the patient has too much range of motion or too little in various joints of the foot). I began doing this based on a number of studies showing muscle weakness and atrophy as well as my experience in my physical therapy clinic treating patients with plantar fasciitis, but this is the first study ever addressing the effects of strength training in the treatment of plantar fasciitis.
Those with plantar fasciitis generally have tight calves. Some stretching is often a good idea, and strength vs stretch needn’t be an either/or affair. However, only stretching has been shown to inhibit muscle strength, and good strength training exercises performed through a full range of motion often stretch while they strengthen giving a 2 for one effect. Researchers in this study went after the 2 for one effect by having subjects do single calf raises on a block, but did so with a folded towel under the toes so that there would be greater toe extension and thus greater tension through the plantar fascia at the top of the motion. At the bottom of the calf raise, the calves are stretched if you go down far enough, which would do much correct the tight calf muscles often associated with the condition. It is unknown if the towel under the toes trick makes the calf raise more effective than a normal calf raise. Initially, I was skeptical, but I tried it and it did feel like it increased plantar fascia tension so maybe there is something to it. However as I reflect upon it logically, I wonder if stretching the plantar fascia is a good idea at all. The plantar fascia is a passive structure that supports the arch of the foot, such that if it is loose, either the muscles will have to work harder, or the arch will collapse slightly, neither of which seem to be a good idea. As such it would be better to just stretch the calves, which have been shown to be tight in those with plantar fasciitis, while the plantar fascia itself has been found to be of normal length.
The protocol used in the study was 3 sets of 12 reps, worked up to 5 sets of 8 reps of single leg calf raises using books in a backpack to increase resistance performed once every other day. The stretching program it was compared to was performed 3 times per day every day and is probably the industry standard as described by Digiovanni.
The unfortunate thing for the profession is that while this study is new and pertinent it probably won’t be seen in the average physical therapy clinic for another 15-20 years, and by then the research will be on to something better, with most therapists still hung up on the latest fad in soft tissue mobilization or needle poking. Evidence based medicine really should be more than a catch phrase.
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Chad Reilly is a Physical Therapist, obtaining his Master’s in Physical Therapy from Northern Arizona University. He graduated Summa Cum Laude with a B.S. Exercise Science also from NAU. He is a Certified Strength and Conditioning Specialist, and holds a USA Weightlifting Club Coach Certification as well as a NASM Personal Training Certificate. Chad completed his Yoga Teacher Training at Sampoorna Yoga in Goa, India.