Development of a foot and ankle strengthening program for the treatment of plantar heel pain: a Delphi consensus study

Key Points

1. A good starting point for most sufferers of plantar heel pain may be the short foot exercise, digital flexion and heel raise variations (with an appropriate load).
2. There does not appear to be much difference in the type of exercises prescribed for the young athletic adult compared to the overweight middle aged or older adult.
3. Exercise selection should always be patient specific/appropriately tailored.

BACKGROUND & OBJECTIVE

The current best practice guide for plantar heel pain made note of the lack of robust RCTs that had been performed with regard to strength/resistance exercises (1). Very recent work by Henrik Riel (2) indicated that there was no additional effect of exercises over giving simple advice and a heel cup. Despite this we know strengthening programmes/exercises are often being used clinically in this cohort of patients.

Regardless of the dearth of evidence to support this practice, perhaps this is still actually sensible; there is data which suggests reduced muscle function, strength and size is associated with people with plantar heel pain compared to people without (3) and improving muscle strength has been shown to be beneficial for other lower limb pathology (4).

The aim of this study was to develop a consensus driven progressive strengthening programme for plantar heel pain. This could have clinical utility (providing information for practitioners who are currently prescribing such programmes) or inform future clinical trials and evaluate the effectiveness of strength training for plantar heel pain.

The current best practice guide for plantar heel pain made note of the lack of robust research that had been performed about strength/resistance exercises.

This framework can help with exercise selection and progression but most importantly dosage for clinicians treating plantar heel pain.

METHODS

• 24 experts were recruited from a range of countries and specialist fields. Clinicians had at least five years’ experience, saw at least five patients with plantar heel pain a month and already prescribed strengthening programs. Of the 24 experts, 15 were educated to PhD level.

• The survey was then conducted over three rounds, with each round helping to inform the following round/s:

  • ROUND 1: OPEN QUESTIONNAIRE Experts provided opinions on the prescription of exercise for managing plantar heel pain, and the results were analyzed for themes/common responses. Following this, three patient types and their vignettes were created (younger athletic adult, overweight middle-aged adult, older adult).

  • ROUND 2: AGREEMENT TO PROPOSED EXERCISES Experts were provided the three different patient types (vignettes) with exercises suggested based on the responses from round one. The experts were asked to agree or disagree with the inclusion of each exercise and its variables (sets, reps, weight and frequency) and could also give further open comments.

  • ROUND 3: AGREEMENT TO AMENDMENTS A repeat of round two, with updated exercises/exercise variables based on the responses from that round. Experts were once again asked to agree or disagree with the exercises presented to them.

• A total of 18 experts completed all three rounds, and consensus was not considered achieved until >70% agreement was met.

RESULTS

Throughout rounds one and two, the three exercises most consistently recommended were the short foot exercise, heel raises and digital plantarflexion (see video), but there was significant variation in how they were described and applied. Of particular interest was the occasional lack of recommendation of the heel raise with digits dorsiflexed due to the difficulty in performing this (despite this being one of the more widely discussed exercises within clinical settings in recent years following the work of Rathleff et al. (6)).

STRENGTHENING PROGRAM FOR PLANTAR HEEL PAIN

The exercises that reached consensus after round three for each of the patient types can be seen in table 4, along with their suggested delivery and progressions.

LIMITATIONS

It is important to acknowledge that whilst this study provides a consensus driven strength programme for use with plantar heel pain patients, we still do not know the effectiveness of the program (or the individual exercises within it) with respect to treating plantar heel pain. Expert opinion, even when achieved via the Delphi method, should not be conflated with robust scientific evidence or support for a given approach.

Additionally (and the authors acknowledged this in their paper) no patient voice or preferences were included in this survey. Clinically, exercises are prescribed not only on an individual basis but often as part of a shared decision-making approach. Previous work has highlighted the potential for patient frustration with prescribed exercises (7) which would have obvious negative impacts on engagement and concordance, so involving them in the process is likely key.

CLINICAL IMPLICATIONS

There are several clinical take homes from this very nicely executed study, as long as they are considered alongside the aforementioned limitations. This framework can help with exercise selection and progression but most importantly dosage. Whereas the set and repetition range may not be novel or much of a surprise to anyone (typically 3-4 sets of 6-12 reps) it is important that the correct resistance is used in terms of bodyweight or repetition max and most notably the frequency with which they should be performed is likely higher than most people may have considered or already be doing – every day for younger athletic adults and every second day for other adults.

What is interesting is that on the whole, the selection of exercises is largely similar between the patient types, with only a few exceptions. For example, the short foot exercise being performed for 4 sets of 8-12 reps alongside banded digital plantarflexion (3-4 sets of 6-12 reps) is a very reasonable starting approach regardless of age or activity, with the caveat that an appropriate load and frequency should be chosen.

Further work will undoubtedly be published on efficacy of exercises for plantar heel pain. Strengthening exercises should not be used alone in the management of this condition, but this study provides a reasonable starting point/scaffold for clinicians treating plantar heel pain who have not been including a strength program within their multi-modal approach and wish to begin to do so.

+STUDY REFERENCE

Osborne J, Menz H, Whittaker G, Landorf K (2023) Development of a foot and ankle strengthening program for the treatment of plantar heel pain: a Delphi consensus study. Journal of Foot and Ankle Research, 16(1), 67.

SUPPORTING REFERENCE

1. Morrissey, D., Cotchett, M., J'Bari, A. S., et al. (2021). Management of plantar heel pain: a best practice guide informed by a systematic review, expert clinical reasoning and patient values. British Journal of Sports Medicine, 55(19), 1106-1118.
2. Riel H, Vicenzino B, Olesen JL, et al. (2023). Does a corticosteroid injection plus exercise or exercise alone add to the effect of patient advice and a heel cup for patients with plantar fasciopathy? A randomised clinical trial. British Journal of Sports Medicine, Published Online First: 06 July 2023. doi: 10.1136/bjsports-2023-106948
3. Osborne, J. W., Menz, H. B., Whittaker, G. A., & Landorf, K. B. (2019). Muscle function and muscle size differences in people with and without plantar heel pain: a systematic review. Journal of Orthopaedic& Sports Physical Therapy, 49(12), 925-933.
4. Rowe, V., Hemmings, S., Barton, C., Malliaras, P., Maffulli, N., & Morrissey, D. (2012). Conservative management of midportion Achilles tendinopathy: a mixed methods study, integrating systematic review and clinical reasoning. Sports Medicine, 42, 941-967.
5. Nasa, P., Jain, R., & Juneja, D. (2021). Delphi methodology in healthcare research: how to decide its appropriateness. World Journal of Methodology, 11(4), 116.
6. Rathleff, M. S., Mølgaard, C. M., Fredberg, U., et al. (2015). High‐load strength training improves outcome in patients with plantar fasciitis: A randomized controlled trial with 12‐month follow‐up. Scandinavian Journal of Medicine & Science in Sports, 25(3), 292-300.
7. Cotchett, M., Rathleff, M. S., Dilnot, M., Landorf, K. B., Morrissey, D., & Barton, C. (2020). Lived experience and attitudes of people with plantar heel pain: a qualitative exploration. Journal of Foot and Ankle Research, 13, 1-9.