Trigger Point Therapy - Treating Plantar Heel Pain

Study provides evidence that trigger point therapy improves the outcome for patients with plantar heel pain

Whilst it's certainly true that we still know comparatively little about trigger points, there is a lot that we do know as a result of an ever growing body of research.

In today's blog we summarize a research study that was completed in 2011 and which looked specifically at the treatment of plantar fasciitis.

About Plantar Heel Pain

Plantar fasciitis or plantar heel pain is the most common foot pain condition treated by healthcare providers. 

It has been estimated that plantar fasciitis occurs in approximately 2 million Americans annually and affects as much as 10% of the general population over the course of a lifetime. 

In fact, some authors have reported that plantar fasciitis accounts for between 8% and 15% of foot complaints in nonathletic and athletic populations. 

Plantar heel pain is disabling, and has a significant negative impact on general health-related quality of life. 

To date, there is evidence that this condition may not be characterized by inflammation but, rather, by non-inflammatory degenerative changes in the plantar fascia.

Clients with plantar heel pain usually describe a sharp pain under the heel, particularly upon weight bearing after a period of non-weight bearing. 

The pain is typically reported being worse in the morning, with the first steps after getting out of bed. 

The pain also typically diminishes with activity but will often tend to worsen toward the end of the day. In some cases the level of disability and affect on daily functions can be quite severe.

Treatment

Both surgical and non-surgical approaches have been proposed for the management of plantar heel pain. 

Clinical practice guidelines have concluded that there has been limited evidence for the effectiveness of corticosteroid therapy, conflicting evidence for low-energy extracorporeal shockwave therapy, and no evidence for therapeutic ultrasound or low-intensity laser, in reducing pain in individuals with this condition.

Among non-surgical interventions, stretching of the gastrocnemius muscle and the plantar fascia have however shown moderate evidence of effectiveness for the management of this condition, although only in the short term.

Trigger Point Therapy - Plantar Fasciitis

Trigger Points and Plantar Heel Pain

Simons et al suggested that taut bands myofascial/muscle trigger points (TrPs) in the gastrocnemius muscles may be involved in the development of plantar heel pain.

A generation or two of trigger point therapists have found this to be the case, and have developed widely used treatment protocols.

TrPs are defined as hyper-irritable areas associated within a taut band of a skeletal muscle that are painful on compression, contraction, or stretching of the muscles, and elicit a referred pain distant to the TrP. 

Studies have found that the stiffness of a TrP taut band is 50% greater than that of the surrounding muscle tissues. 

It is probable that the increased stiffness induced by taut bands with TrPs may reduce the effectiveness of muscle stretching alone.

Therefore, as soft tissue work may help further improve the effectiveness of stretching in the management of plantar heel pain, a randomized controlled clinical trial was undertaken in 2011 to compare the effects of combined stretching and TrP manual therapy to stretching alone.

Details of the Study

Sixty patients, 15 men and 45 women with a clinical diagnosis of plantar heel pain were randomly divided into 2 groups: a self-stretching (Str) group who received a stretching protocol, and a self-stretching and soft tissue TrP manual therapy (Str-ST) group who received TrP manual interventions (TrP pressure release and neuromuscular approach) in addition to the same self-stretching protocol.

The primary outcomes assessed were physical function and bodily pain as related to a quality of life questionnaire.

Additionally, pressure pain thresholds (PPT) were assessed over the affected gastrocnemii and soleus muscles, and over the calcaneus, by an assessor blinded to the treatment allocation.

Outcomes of interest were captured at the baseline and at a 1-month follow-up which was the end of the treatment period. 

Self Stretching Protocol

All participants were instructed in a self-stretching protocol, including calf muscles and plantar fascia-specific exercise, which has moderate evidence of effectiveness for the management of plantar heel pain. 

The dosage for calf and plantar fascia-specific self-stretching exercises was 2 times per day, using intermittent stretching of 20 seconds, followed by 20 seconds rest for a total of 3 minutes for each stretch. Hence, the total self-stretching protocol lasted 9 minutes. 

Trigger Point Therapy

The TP control group were examined for the presence of active TrPs in the gastrocnemius muscles by a clinician with more than 5 years of experience in the management of TrPs.

TrP diagnosis was conducted according to: (1) presence of a palpable taut band, (2) presence of a hypersensitive area in the taut band, (3) local twitch response provoked by the snapping palpation of the taut band, or (4) reproduction of referred pain in response to compression. 

These patients received a TrP pressure release technique over both gastrocnemii muscles. Pressure was applied over TrPs until an increase in muscle resistance (tissue barrier) was perceived by the clinician. 

The pressure was maintained until the therapist perceived release of the taut band. At this stage, the pressure was increased to return to previous level of muscle TrP tension and the process was repeated for 90 seconds (usually 3 repetitions).

These patients also received a neuromuscular technique (longitudinal stroke) over the gastrocnemius muscle.

This is a technique has been found to be effective for reducing TrP pressure sensitivity. 

With the patient in prone, the thumb of the therapist was placed over the taut band and 3 longitudinal strokes were performed from the ankle to the knee. 

In each case, TrP manual therapies were applied depending on clinical findings related to the location of the TrP on the affected leg. No predetermined TrP location was considered.

Results

The 2 × 2 mixed-model analysis of variance (ANOVA) revealed a significant group-by-time interaction for the main outcomes of the study: physical function (P = .001) and bodily pain (P = .005); patients receiving a combination of self-stretching and TrP tissue intervention experienced a greater improvement in physical function and a greater reduction in pain, as compared to those receiving the self-stretching protocol.

The mixed ANOVA also revealed significant group-by-time interactions for changes in PPT over the gastrocnemii and soleus muscles, and the calcaneus (all P<.001).

Patients receiving a combination of self-stretching and TrP tissue intervention showed a greater improvement in PPT, as compared to those who received only the self-stretching protocol.

Conclusions

This study provides evidence that the addition of TrP manual therapies to a self-stretching protocol resulted in superior short-term outcomes as compared to a self-stretching program alone in the treatment of patients with plantar heel pain.

The above is a summary of the study: Effectiveness of Myofascial Trigger Point Manual Therapy Combined With a Self-Stretching Protocol for the Management of Plantar Heel Pain: A Randomized Controlled Trial. This was published in Journal of Orthopaedic & Sports Physical Therapy, 2011 Volume:41 Issue:2 Pages:43–50 DOI: 10.2519/jospt.2011.3504

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