Treatment of Plantar Heel Pain - A Literature Review

Original Editor - Merinda Rodseth based on the course by Bernice Saban

Top Contributors - Merinda Rodseth, Kim Jackson, Jess Bell and Tarina van der Stockt  

Introduction

Plantar heel pain (PHP) is regarded as a multifactorial condition with many factors proposed to be associated with it . PHP is generally viewed as a self-limiting condition and for the majority of individuals with PHP, the symptoms resolve within one year without any therapeutic intervention . Twenty percent of individuals, however, continue to experience PHP beyond a year . The aetiology of PHP is generally not well understood which causes uncertainty regarding the most effective management thereof, making the condition difficult to effectively treat . Combined with this, there is also a lack of high quality evidence regarding optimal treatment which leaves clinicians with a variety of treatment options but no clear evidence on what works best and no firm, evidence-based clinical advice on the optimal management of PHP .

With no clear guidance, Grieve et al conducted a survey on which interventions Physiotherapists in the United Kingdom (UK) then use for PHP (Figure 1).

Figure 1. Interventions used by Physiotherapists in the UK for PHP

This again highlights the need to search the available research to establish which treatment options are available and effective in the management of plantar heel pain syndrome (PHPS). When considering the research, it is important to keep in mind that the term “significant difference” is a statistical value and not always reflective of a difference/change that would be meaningful for the patient. It is therefore also important to consider the “Minimal important difference” (Minimal clinically important difference/change) or the “smallest change in treatment outcome that an individual patient would identify as important, and which would mandate a change in the patient’s management” .

Which treatments should then be used for patients with PHPS? The following physiotherapy and medical treatments will be discussed in this review, with the aim of identifying treatment options supported by high-quality research studies (Figure 2).

Figure 2. Treatment options proposed for PHPS

Physiotherapy Treatments

A large variety of physiotherapy treatment options for PHPS have been discussed in the literature and will be reviewed in the following section (Figure 3).

Figure 3. Physiotherapy treatment options proposed for PHPS

Ultrasound

Therapeutic ultrasound is one of the most widely used electrical devices among physiotherapists worldwide even without the support of sufficient high-quality evidence for its use in musculoskeletal conditions . Many studies investigated the use of ultrasound and found therapeutic ultrasound to be ineffective for the treatment of PHP and its use is therefore not recommended for individuals with PHPS (Figure 4) .

Figure 4. Studies investigating the treatment of PHP by ultrasound

Stretching

Stretching of the triceps surae muscles has been proposed in many studies as an essential part of the management of plantar fasciitis . The aim of stretching is to release tension in the Achilles tendon and plantar fascia, both of which attach to the calcaneus . Many studies have investigated the use of stretching for the treatment of PHPS, often with conflicting results. Several studies compared the use of various stretches for PHPS and generally found that all groups improved with Barry et al also reporting a shorter recovery time with the use of night splinting (Figure 5) .

Figure 5. Research studies comparing various stretching regimes

Some studies compared stretching to various other treatment interventions (sham US, ESWT, strengthening) and generally found no differences between groups, that all groups improved. Stretching was thereby not superior to other forms of treatment (Figure 6) .

Figure 6. Stretching compared to other forms of treatment

In a systematic review analysing the effectiveness of manual stretching for PHPS, Sweeting et al reported:

• Conflicting results
  • One study showed placebo to be equally effective to stretching
  • Another study showed stretch to be more effective than EWST
• Intermittent or sustained methods of stretching were equally effective
• Plantar fascia NWB stretch could be more effective than dorsiflexion WB stretch

Strengthening

Weakness of the intrinsic foot muscles as well as the ankle plantar flexors have been proposed as risk factors for the development of PHPS and prompted the use of strengthening as a treatment for PHPS . Several studies investigated the effect of strengthening on PHPS and reported improvement in all groups with no advantage to strengthening in the management of PHPS, except after 3 months of plantar-specific stretching (Figure 6) .

Figure 6. Effect of strengthening on PHPS

Manual Therapy

Physiotherapists often use manual therapy to improve joint mobility, mobilise soft tissue and reduce pain . Current literature on the use of manual therapy for patients with PHP is however sparse and often of lesser quality . Cleland et al conducted a study on the efficacy of manual therapy and exercise (MTEX) compared to electro-physical agents and exercise (EPAX) in the management of PHPS (Figure 7). Both treatment groups however, received multiple different interventions which is problematic for interpreting which intervention made the difference (Figure 8). They concluded that all patients improved with statistically significant differences between groups regarding pain and global improvement favouring MTEX (Figure 9) . There is however not enough information about the clinical effects of the treatment.

Figure 7. Manual therapy and exercise compared to Electro-physical agents and exercise for PHPS

Figure 8. Treatment details of the groups in the study by Cleland et al

Figure 9. Results of the comparison between Manual therapy and electro-physical agents for PHPS

Shashua et al also investigated the effect of manual therapy on plantar fasciitis (Figure 10) with the treatment group receiving manual therapy, ultrasound and stretch exercises and the control group only ultrasound and stretch exercises (Figure 11). They reported an improvement in both groups with no difference between groups, indicating no additional advantage to manual therapy for PHPS (Figure 12).

Figure 10. Manual therapy for Plantar fasciitis

Figure 11. Treatment details for both groups in the study by Shashua et al

Figure 12. Results on the effect of manual therapy for plantar fasciitis

Taping

Taping is proposed to be associated with pain reduction, increased circulation and improved proprioception, all of which would be beneficial for the management of PHPS . Radford et al applied standardised leukotape to the plantar skin of patients and kept it in situ for 7 days, which they compared to a control group. Both groups improved and there was no significant reduction in heel pain intensity in the taping group compared to the controls . First step pain, however, was significantly better in the taping group compared to the controls (Figure 13) .

Figure 13. Effectiveness of low-Dye taping for the treatment of PHPS

Tsai et al compared the use of kinesiotape for plantar fasciitis, applied over the gastrocnemius and plantar fascia and kept in situ for one week, to a control group (Figure 14). Both groups reported a significant reduction in pain and there was a significant difference in pain reduction between the groups, but this was also reported before intervention. No differences in plantar fascia thickness were found between groups . This study, however, had insufficient information to accurately interpret its measurements and come to a final conclusion about the treatment effects (Figure 15) .

Figure 14. Kinesiotaping versus control group

Figure 15. Results of the study by Tsai et al

Dry Needling

The presence of myofascial trigger points within the musculature of the plantar foot as well as the muscles proximal to the foot, has been proposed to play a role in PHPS . Dry needling of these myofascial trigger points has therefore been proposed for the management of plantar fasciitis . Limited evidence for the effectiveness of dry needling was however reported in a systematic review on dry needling for PHPS and the poor quality of the studies precluded making definite conclusions . Following this, Cotchett et al conducted a study to determine the efficacy of trigger point dry needling for PHPS (Figure 16) and compared “real dry needling” into the myofascial trigger points of a variety of muscles (Figure 17) to sham dry needling. They found that even though real dry needling provided statistically significant reductions in PHP compared to sham dry needling, the size of the effect was not clinically meaningful (Figure 18) .

Figure 16. Effectiveness of trigger point dry needling for PHPS

Figure 17. Different muscles in which trigger points were dry needled

Figure 18. Outcome of real vs sham dry needling

Cryotherapy

Ice/cryotherapy is generally considered as a basic component in the management of any injury due to its proposed effectiveness in reducing swelling and relieving short-term pain . It has thereby also been proposed as a treatment option for PHP as for many other musculoskeletal conditions . Costantino et al conducted a study comparing cryoultrasound to only cryotherapy and found that all patients improved but the ultrasound group showed a larger improvement (Figure 19).

Figure 19. Cryoultrasound vs cryotherapy for chronic plantar fasciitis

Medical Treatments

Varying between countries and depending on the scope of practice, many of the following treatments are often not performed by physiotherapists but rather medical doctors, and mostly used after failure of conservative management (Figure 20).

Figure 20. Proposed medical treatments for the management of PHPS

Orthotics

Four high quality studies investigating the effect of a variety of foot orthoses/insoles in PHPS were identified (Figure 21 and Figure 22) . They provided varied and somewhat conflicting results on the efficacy of various insoles for PHPS and generally reported improvement in all groups with no consistent benefit to any one orthosis (Figure 23) .

Figure 21. Good quality studies on the use of orthoses/insoles for PHPS

Figure 22. Study details of the four studies on orthoses for PHPS

Figure 23. Results on the most effective insole for PHPS

Winemiller et al compared the effect of magnetic versus sham-magnetic insoles on PHP and found no benefit to magnetic insoles compared to sham-magnetic inserts (Figure 24).

Figure 24. Magnetic insoles vs sham-magnetic insoles for PHP

Extracorporeal Shock Wave Therapy

Extracorporeal shock wave therapy (ESWT) has been used since 1976 to disintegrate kidney and gallstones (lithotripsy) and for several decades as a non-invasive pain-relief treatment option for failed conservative management of plantar fasciitis before surgical intervention . ESWT involves an electromagnetic system where a magnetic field in a surrounding fluid medium is used to produce shock waves . Abrupt, high-amplitude pulses of mechanical energy (similar to sound waves) are generated by an electromagnetic coil or a spark in water . The shock waves are proposed to stimulate angiogenesis (new blood vessels) and neurogenesis (new nerve cells) . Its mechanism of action is still not well understood but proposed to be through the destruction of unmyelinated nerve fibres with simultaneous stimulation of neovascularisation and collagen synthesis . The cells therefore appear to undergo micro trauma which promotes the inflammatory and catabolic processes associated with the removal of damaged matrix waste and stimulation of wound healing mechanisms . In short, ESWT should:

• Increase blood supply
• Improve collagen remodelling
• Enhance waste elimination

Several studies, many of poor methodological quality, explored the effect of ESWT on PHPS with conflicting results (Figure 25).

Figure 25. Evidence for the use of ESWT in PHPS

Of the studies reviewed, only Gerdesmeyer et al reported a significant improvement in pain, function and quality of life with ESWT whereas others had conflicting results. Rompe et al compared ESWT to stretching techniques and found stretching to be more advantageous than ESWT at 2 and 4 months (Figure 26).

Figure 26. ESWT compared to a stretching regime for PHPS

Following the results of their systematic review, Yu et al reported inconsistent evidence on the effectiveness of ESWT for PHPS and stated that the current evidence does not support the use of ESWT for PHPS.

Steroid Injections

Corticosteroid injections are used in multiple musculoskeletal conditions, including PHP, as a way of relieving pain . In a Cochrane review, David et al reported low quality evidence that local steroid injections may slightly reduce PHP for up to one month, compared to placebo or no treatment (Figure 27).

Figure 27. Cochrane review of injected corticosteroids for the treatment of PHP

Surgery

Surgical interventions are generally not considered for plantar fasciitis until conservative treatment has been thoroughly pursued  and symptoms have been present for more than 6 months . Plantar fasciotomy will only be considered if conservative therapies have been ineffective and significant symptoms continue to persist . Plantar fasciotomy involves:

• an open procedure
• either a partial release of the medial one-third of the plantar fascia
• or a complete release of the fascia

The outcomes following plantar fasciotomy vary but generally shows good early pain relief and return to function in the short term . Many individuals however experience ongoing pain and functional limitations and a retrospective study by Gibbons et al demonstrated that even though 72% of patients reported long-term satisfaction with the surgery, 44% continued to experience ongoing pain, swelling and tenderness (Figure 28).

Figure 28. Long-term outcomes following plantar fasciotomy

Conclusion

From the literature explored it seems that stretches could possibly help for PHPS and strengthening may be beneficial but the available evidence does not support any of the commonly used treatments for PHP as significantly better than any other .  At the moment there is limited evidence upon which to base clinical practice which poses a professional spur for clinicians as it relates to the risk factors, assessment and management of PHPS.

From the literature reviews on these topics in PHPS, there is some information on the risk factors associated with PHPS, no evidence for the assessment of PHPS and very little information on the management thereof (Figure 29) which prompts us to the next lecture in the series, the pursuing of a new protocol for PHPS .

Figure 29. Known variables from the literature reviews on risk factors, assessment and treatment of PHPS