Plantar heel pain

Inspired by Al-Boloushi et al 2020,[1] and Ho et al 2020.[2]

Photo by Min An on

These two papers came out towards the end of August and have been waiting to be aired. They both involve needling with filiform acupuncture needles, and they both have ‘plantar heel pain’ in their titles, so they naturally fit together, and illustrate some interesting points of contrast.

The first paper was a comparison of two needling interventions: dry needling (DN) in the style of Chang-Zern (John) Hong, and the same type of needling with the addition of 1.5mA of galvanic current passing through the needle (so called PNE – percutaneous needle electrolysis). We published a paper on PNE for lateral epicondylitis some years ago in Acupuncture in Medicine.[3] This paper described using 4–6mA, and there was no dry needling action mentioned.

DN – dry needling

PNE – percutaneous needle electrolysis

EA – electroacupuncture

EAWN – electroacupuncture plus warm needling therapy

key to acronyms

John Hong spoke and demonstrated his preferred needling technique at a BMAS meeting in London some years ago. I had suggested him as a speaker because of all his papers studying myofascial trigger points. He wrote a really useful review paper with Dave Simons in the late 90’s that I cited extensively for some time after.[4] It was Hong that demonstrated that the local twitch response was likely to be a spinal reflex.[5] He was academically a bit of a hero to me in the 90’s, but when he came to demonstrate his needling technique I was rather shocked. He used a long blue (23G 0.6mm diameter) hypodermic needle on a syringe, which he held a bit like you would hold a fork to shovel peas (of course I am not suggesting any of you sophisticated readers would ever commit such a crime against British etiquette). He used a fast in fast out technique and preferred to inject a tiny spot of lignocaine as the needle was in the target. He was quite efficient at doing this by having his right index finger permanently sitting on the plunger of the syringe. But it was still a little shocking to see the multiple insertions of a hypodermic needle. I was imagining the tissue trauma and realised that probably explained the results of one of his trials that showed injection was associated with less post needling soreness than dry needling.[6] As we have seen many times at BMAS meetings, the characters who perform the more brutal treatments have often never been introduced to the more gentle techniques available with fine filiform acupuncture needles.

…those who perform the more brutal treatments

Anyway, to get back to the DN versus DN plus PNE paper, you can probably imagine now that both groups got some serious needling applied to their calf muscles and feet every week for 4 weeks, and one lucky group got the added bonus of simultaneous galvanism. It will be no surprise that the immediate dropout rate was 18% in the DN group and 27% in the DN plus PNE group. By the end of the trial the dropout rate was 25% and 41% respectively. For the majority of the trial there were no differences between groups, but after 41% had dropped out of the DN plus PNE group it just nudged ahead in terms of quality of life (EQ-5D)… I wonder what sort of quality of life the patients experienced for a few days after each treatment.

…the added bonus of simultaneous galvanism

The second paper on plantar heel pain uses a waiting list control, despite having efficacy in the title. The waitlist group got free treatment after the end of the trial, and they would not have been too disheartened about being randomised to wait, since it was only 4 weeks. The active group got 6 sessions over 2 weeks of electroacupuncture (EA) to KI5 and the tender point on the heel, with needles inserted 20mm. Moxa was applied to the needles during EA, hence EA plus warm needling therapy (EAWN therapy). There were no dropouts in this trial and the significant benefits at 4 weeks over waiting list appeared to be maintained at 8 weeks follow-up of this group.

Unfortunately, we cannot compare the outcomes because different scales were used, and the populations were also a little different. The DN/PNE trial was set in a physical medicine and rehabilitation hospital in Kuwait, the patients were around 50 years old on average with BMIs of 33–35. By contrast the EAWN therapy trial was set in Hong Kong with patients of around 60 years old and normal BMIs (~23).

Is any of this going to change my practice? No, I will continue to use local EA with the finest needles I can get to the target, but these two papers do give me a little more confidence that it may be worth doing rather than just waiting for natural history to kick in.

Reference list

1         Al-Boloushi Z, Gómez-Trullén EM, Arian M, et al. Comparing two dry needling interventions for plantar heel pain: a randomised controlled trial. BMJ Open 2020;10:e038033. doi:10.1136/bmjopen-2020-038033

2         Ho LF, Guo Y, Ching JY-L, et al. Efficacy of electroacupuncture plus warm needling therapy for plantar heel pain: a randomised waitlist-controlled trial. Acupunct Med 2020;:096452842094604. doi:10.1177/0964528420946048

3         Valera-Garrido F, Minaya-Muñoz F, Medina-Mirapeix F. Ultrasound-Guided Percutaneous Needle Electrolysis in Chronic Lateral Epicondylitis: Short-Term and Long-Term Results. Acupunct Med 2014;32:446–54. doi:10.1136/acupmed-2014-010619

4         Hong CZ, Simons DG. Pathophysiologic and electrophysiologic mechanisms of myofascial trigger points. Arch Phys Med Rehabil 1998;79:863–72.

5         Hong C-Z, Torigoe Y. Electrophysiological characteristics of localized twitch responses in responsive taut bands of rabbit skeletal muscle fibers. J Musculoskele Pain 1994;2:17–43.

6         Hong C-Z. Lidocaine injection versus dry needling to myofascial trigger point. The importance of the local twitch response. Am J Phys Med Rehabil 1994;73:256–63. doi:10.1097/00002060-199407000-00006

Declaration of interests MC