Strength Better than Stretch for Plantar Fasciitis

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.

My comments:

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.

Thanks for reading my blog. If you have any questions or comments (even hostile ones) please don’t hesitate to ask/share. If you’re reading one of my older blogs, perhaps unrelated to neck or back pain, and it helps you, please remember Spinal Flow Yoga for you or someone you know in the future.

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.

5 thoughts on “Strength Better than Stretch for Plantar Fasciitis”

  1. “However as I reflect upon it logically, I wonder if stretching the plantar fascia is a good idea at all.”

    –> I agree. I mean, I wonder as well. I’ve gotten PF in the course of spring/summer/early fall this year, probably from doing to much speed work in running in combination with poor nutrition, poor recovery, too much weight in my backpack and hiking too long with a heavy backpack in stiff/hard boots.
    I also stated lifting heavy weights (5×5) program at the same time and might have progressed too fast (it was just too much fun, esp the deadlift).

    So here I am with one foot much worse than the other, spending hours online finding the optimal treatment.
    I’m also a home student in anatomy&physiology, and tried to look at PF more logically.

    And I could never understand why there are those advices on stretching the fascia itself, when it is not supposed to stretch, but rather give support (I think it stretches as little as 5% or so, so it’s not completely rigid).
    I have never tried the “rolling you foot over an ice bottle” exercise.

    It doesn’t make sense to me.
    My physical therapist told me that yes, my calves are tight, but he had seen worse.
    Generally, I have high mobility but tend to get sore muscles really easily, especially in my upper back and neck.
    I also don’t recover very fast but I’m a fairly “quick responder” to training, so I could get away with minimal (triathlon) training and still do quite well.

    I definitely want to try the strengthening exercise for my calves.
    As for the additional towel: I’ll try that as well. But – my toes are really flexible, 90degrees of dorsiflexion is no problem at all – no tension in the fascia either.
    My entire foot is remarkably flexible according to my PT, so I wouldn’t get far with stretching the fasica anyway I guess.

    But my muscles definitely need more strength, so weight/strength training makes even more sense in my case I guess.
    Btw calf raises is something I hadn’t done in years – I also have rather weak glutes (all three) so I’m planning to do more strength training, and do stretching of my muscles (rather then the fascia).

    There are a few articles showing that exercises for stretching the fascia are superior to exercises for stretching the achilles tendon, but one can wonder what are the causes and effects here – maybe stretch exxercises for the fascia actually stretched out the muscles more than the fascia itself, and blood circulation improved as well, leading to benefits on a cellular level?

    Anyway, great to see someone questioning traditional pf treatment, makes me want to find out even more about what plantar fasciitis is all about (and how to get rid of it of course 😉 ).

    • Hi Imke:

      You have great comments and questions and I would encourage you to read through my other blogs under the keyword “plantar fasciitis” and under the category “running injuries”. Those expound on a number of studies that to me point towards the conclusion that plantar fasciitis should be treated like tendinitis/tendinopathy with strength protocols more so or rather than stretching. Like you, I don’t think stretching the plantar fascia is generally a good idea, so when I do calf strengthening with plantar fasciitis I don’t use the towel under the toes like in this study. I just mentioned that they did because they did, but there is no evidence to say that it works better or worse than a regular calf raise.

      Research shows that the calf muscles are often tight in those with plantar fasciitis but you mention yours are only moderately so. As such, if you do the calf raises through a full range of motion off a block, you will likely be stretching them adequately with every repetition. I think your 5×5 weights program is overall a good one, but if I recall correctly it doesn’t have any exercises that target the calf muscle, tibialis anterior, tibialis posterior, hip abductors and adductors directly. For the hip adductors and abductors, I use both a hip in and hip out machine, as well as side lying hip abduction exercises. For physical therapy (as opposed to fitness, where I use more variety of sets and reps) I have my patients do 3 sets of 15 reps each, consisting of a relatively easy set, a medium set, and a hard set where it is difficult or impossible to get the last 15 reps. I have patients increase the weight on all 3 sets when they can do the 3rd heavy set for 15 reps with good technique. I think the deadlifts and squats you are doing on the 5×5 program should take care of general hip and thigh strengthening, and I don’t have any problem with using 5 reps, however 3×15 as described above is how I do all my exercises when I am rehabilitating an injury. The higher reps might be more specific to your running with the higher reps imparting more muscular endurance, but the high weight low rep work has it’s advantages as well. Also while in one of my blogs I mention that arch support orthotics don’t seem to have much impact on recovery in the long term with plantar fasciitis, in the short term I have a lot of patients say they help and they are relatively inexpensive so might be worth a try. Last I think you want to strengthen your foot intrinsic muscles which help to support the arch of the foot and thus take pressure of the plantar fascia. The short foot exercise might help but I think I get the most intense foot intrinsic muscle contractions with electric muscle stimulation (EMS) where you stand on the electrodes with one under the ball of the foot and one under the heel.

      My favorite EMS unit (Globus Genesy) I think is easier to get in Europe than here and I program it for a 10 minute treatment, 10 seconds on, 50 seconds off, with 450 uS pulse width, 120 Hz, and a ramp up of 1500 ms and 500 ms ramp down. A less expensive unit that still usually works well for home use is the Everyway Medical EV-906 which I program to the same parameters but for 12 minutes of treatment with 300 uS pulse width, only because that’s what maxes out the machine. I use 10 cm rubber carbon electrodes. The EMS protocols I use is basically the Russian Stimulation duty cycle but with the more modern biphasic square wave current. Another benefit of the EMS is that my patients all report it reduces pain immediately, which I think is by gate control theory like TENS, but since EMS current is more intense than TENS I suspect that’s the reason reduction is often better. The above EMS and electrode placement and I got from sprint coach Charlie Francis’s book, which he said worked well with his track athletes when they had foot injuries. In my experience the combination approach of global core and leg strengthening with an emphasis on leg muscle below the knee, and hip adductor abductor muscles, with EMS to to foot intrinsics works really well.

      I don’t think ice helps with healing plantar fasciitis nor is it worth the effort. A study done on exercise with and without ice for tennis elbow found ice has no effect. Also for general weight training I use Romanian Deadlifts (RDLs) way more often than conventional deadlifts. Not because there is anything wrong with regular deadlifts, but because I think conventional deadlifts are more similar to squats, while RDLs I think better target the hamstrings and glutes with the lesser knee bend lessening the contribution of quadriceps, which should already be getting worked pretty hard with squats. I often use lunges in my program which I think gets a bit more gluteus maximus but also the legs in general.

      Since I haven’t evaluated you I don’t feel comfortable telling you what you should do, so rather I’m sharing how I currently treat my physical therapy patients and why. As you can probably tell I like to talk and write about this stuff, so if you have any other questions please feel free to ask.


  2. Hi Chad. I’m sorry to bother you, and I feel a bit cheeky asking a stranger for advice but I’ve read your work and I can see you are a PT who really knows his stuff and keeps up to date with the latest research (that is impossible to find here in Thailand).
    I’m a professional kickboxer but I’ve been going through an injury nightmare for the past few months that has stopped me from competing. I got a vestibular injury in April that stopped me from training for 2 months, then when I recovered from that I went back to training too hard and gave myself achilles tendinosis in my left leg. I stopped all running and kickboxing and tried to rehab the achilles with heavy standing and seated calf raises but must have gone too heavy, too quickly because I developed plantar fasciitis in both feet. So now I’m here with achilles tendinosis and plantar fasciitis and I’m desperate to heal so I can get back to fighting (which is my main source of income) but I don’t know what approach to take. I feel bad asking a professional for free advice but if you could give me a few pointers I would be so grateful.

    • Hi Jonny, I think it’s awesome you’re asking questions. I get to help a pro-fighter in Thailand, how cool is that!? My answer is maybe a bit long and detailed, but I’m thinking I’m going to make it into a blog by itself and I have a video I want to edit, but this should get you started.

      It sounds like you were doing basically the right stuff, you maybe just did too much of it. I’m of the opinion, which is based on both experience as some research, that resting a tendon doesn’t really help. Maybe if you are running way too much jumping back into training after a break you might want to tone it back a bit, but I wouldn’t stop training and running all together. Every time I have had a person try that (regardless of the sport or area of tendinopathy) they think they are doing great with their strength training, then they return to running or whatever and the pain comes right back. So I advise people to keep running and in your case training the kickboxing too, which I wouldn’t expect to slow recovery at all, and you can better judge whether your tendon is actually healed or not. I think a little bit of running and training every day is better than greater amounts every other or every few days, then as you are feeling better you can GRADUALLY increase your training volume.

      About the Achilles tendinopathy, I’ve been meaning to do a new blog/vlog just on that because I think I have simplified my protocol, which I think is easy for home training and I’ve had several friends try it and they all say they got better. Basically it’s this:

      Exercise: single legged calf raises on a block (two legged calf raises OK if single leg too hard or painful)
      Sets: three
      Reps: as many as you can
      Weight: none, other than bodyweight (partial bodyweight if using both legs)
      Rest Period: none
      Frequency: once per day, every day

      I know some of the earlier tendinopathy research with eccentric exercise (I use body concentric and eccentric now) used 6 sets of 15, 3 sets with the knees straight and three sets with the knees bent, but there are some more recent papers suggesting that while effective that might be overkill, and I personally don’t think bent knee calf raises offer anything that the straight legged version doesn’t do. I think the soleus is trained just fine straight or slightly bent knee calf raises. Just doing body weight, you won’t overextend yourself, and by going back and forth between right and left legs without rest, you should get a hella good burn. It’s the short rest that makes it hard. There are a couple ways to go with it, which I don’t expect it makes a lot of difference. You could start with three sets of 10, then over the next few days progress that to 12s, 15s, 20s. I have fairly strong calves and with the short rest periods my calves are burning pretty hard and my technique starting to break down (less than full range) before I hit 20 reps. The other way would be to do as many reps as you can on the first set (I think I’ve done 50) then on the 2nd set I’ll maybe get 25, and the third set 15 with range of motion suffering a lot by the end.

      What seems to be most important with tendinopathy is to get the right amount of tension for the right amount of time. Such that a lot of impact like depth jumps would likely be too much in intensity and not enough duration of tension. Light prolonged exercise would have more duration than necessary, but not enough intensity to matter or cause the tendons to adapt/remodel/heal. Nobody knows what is ideal but 3 sets of 15 done daily has always seemed about right and is in the ballpark of the majority of the tendinopathy research. With Achilles tendinopathy I’ve started just adding reps rather than weight (also valid) as you get stronger and so far I’m batting a thousand on people getting better.

      Given that you are a pro fighter, I’m making the assumption that you are otherwise really fit, such that I don’t think you would have to do a bunch of additional exercises outside your current routine. If I had a couch potato come into my office for therapy, I’d include more of a general strength and conditioning routine in addition to the calf raises. Likewise, if the patient was obese, the combination of increased body weight, perhaps combined with lesser calf muscle strength would make single leg calf raises too intense to get started with, making bilateral calf raises maybe the place to start. Another problem is that going from double to single calf raises is a 100% increase in resistance level such that if the tendinopathy is severe and the person is both heavy and unfit, using a calf raise machine at the gym and doing 3 sets of 15 reps might be more appropriate, even if it is less simple. Fortunately, for you, I think just the single leg calf raises will work just fine.

      Now regarding your plantar fasciitis, the good news is that the above research paper found that calf raises also helped with plantar fasciitis. They did so with a pad under the toes to further stretch the plantar fascia, however it’s my opinion that this extra plantar fascia stretch is unimportant, and according to my reasoning might even be counterproductive.

      Also I think increasing posterior tibialis strength would help support the foot arch and I think can be trained effectively with your calf raises particularly if you try to rise up with the center of the pressure going more towards the outside (lateral aspect) of the ball of your foot. It would be your tibialis posterior that would be primarily responsible in shifting your weight to the outside ( very slightly inverting the ankle as you rise up) of the foot. The way I do it, it’s more of a shift in pressure to the outside of the foot than an ankle inversion that you can see. So maybe do the first 1-2 sets of your calf raises regular, and maybe the the last or last two sets with the lateral pressure. Alternatively you could do the first set regular, the 2nd set pressing through the outside of the ball of the foot and he last set pressing through the inside of the ball of the foot (emphasising the fibularis muscles) which might not support the arch might overall better stabilize the ankle. That’s all my speculation as I don’t know of any EMG research that shows I’m right, but it feels right when I do it. Note this is different from the oft made recommendation to do some of your calf raises with your toes out and toes in (which I think is just hip internal and external rotation) that has little differential effect with regards to working your inner and outer calves, but I think it the rotation might have some overlapping principles and maybe muscle action with what I’m doing with my weight shift.

      As for foot intrinsic muscles, there was a blog I did about research on the “short foot exercise” but I’m a bit skeptical that the short foot exercise is reliably intense enough to make a lot of difference. So if I want to strengthen the foot intrinsic muscles, I just have my patients step on some EMS electrodes as sprint coach Charlie Francis taught in his book the Charlie Francis Training System. I use his (actually Yakov Kots’) 10-50-10 protocol, but with a more modern biphasic square wave current. The reason you stand on the electrodes is that with a good EMS unit (my favorite being a programmable Globus Genesy 300 Pro) your body weight holds your foot in a reasonably comfortable position while the EMS blasts the foot intrinsic muscles, while if you were not weight bearing the muscle contractions and resultant foot cramps would be nigh unbearable. I’m not sure if Globus EMS units are available in Thailand but they will do a lot more than just train your feet. Other units I’m sure are good too, I just don’t know of anything as good or with the feature to customize programs like the Globus. The best part of the EMS to the feet is it not only strengthens the muscles but also does a good job of decreasing pain in the short term. I think the EMS is ideal, but probably not essential, and I have had people get their plantar fasciitis better with just the calf raises, but I think the EMS helps a lot.

      That’s most of my tricks. If you have any other questions feel free to hit me back.

  3. Hi Chad

    I got tendonitis 3 weeks ago due to lack of use really. Hadn’t participated in any moderate/vigorous physical activity in the past 5 months due to knee pain. Would sticking to a 3 x 15 1 leg calf raise be best for me? Thanks, for all you work.


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