Skip to content

Targeted care for chronic plantar heel pain: Shockwave therapy for bone marrow lesions (the BALSA trial)

Efficacy of shockwave therapy for pain in participants with a bone marrow lesion phenotype of chronic plantar heel pain: the BALSA trial.

Status
Recruiting
Phases
Unknown
Study type
Interventional
Source
ANZCTR
Registry ID
ACTRN12624000260527
Acronym
BALSA (Bone mArrow Lesions and ShockwAve)
Enrollment
8
Registered
2024-03-15
Start date
2024-09-02
Completion date
2024-12-31
Last updated
2024-09-09

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

None listed

Brief summary

Up to 50% of people with chronic plantar heel pain have a bone marrow lesion (BML) in the calcaneus. Calcaneal bone marrow lesions are high signal lesions on MRI that are associated with having chronic plantar heel pain and with poorer longer-term pain and function outcomes. Shockwave therapy is an approved therapeutic device in Australia for treating musculoskeletal pain, including plantar heel pain. It emits high levels of acoustic energy that has been shown to improve pain and shrink bone marrow lesions at other body sites, but it has never been tested for its effect on pain in people with a bone marrow lesion sub-type of chronic plantar heel pain. The primary aim of this study therefore is to determine whether shockwave therapy is effective at improving pain in a BML-positive subgroup of participants with chronic plantar heel pain. Ninety participants will be randomly allocated to either an active or sham shockwave group (45 per arm), each receiving one treatment per week over three weeks. Pain will be assessed by validated questionnaire at baseline, 4- and 12-months to determine if shockwave is effective at reducing pain. Secondary measures for physical function and quality of life will be assessed at baseline, 4- and 12-months and perception of global rating of change assessed at 4- and 12-months. As an exploratory analysis BML size will be measured by MRI at baseline and 4-months to determine if change in BML is associated with change in pain.

Interventions

Shockwave & advice Three sessions of radial shockwave, directed at the plantar calcaneus, will be provided at weekly intervals, delivered using the same branded machine (EMS Swiss DolorClast Master Touch). Visualising the bone marrow lesion (BML) location on MRI is not required as all lesions must be in a plantar location and therefore accessible to topical shockwave application. However shockwave application will be directed to the most painful aspect of the plantar heel, marked prior to applic

Shockwave & advice Three sessions of radial shockwave, directed at the plantar calcaneus, will be provided at weekly intervals, delivered using the same branded machine (EMS Swiss DolorClast Master Touch). Visualising the bone marrow lesion (BML) location on MRI is not required as all lesions must be in a plantar location and therefore accessible to topical shockwave application. However shockwave application will be directed to the most painful aspect of the plantar heel, marked prior to application with an indelible pen. Each session will last less than 20 minutes and details of treatment (machine settings, total session energy dose, maximum energy intensity, participant response) will be recorded on a treatment log for each participant. Treatment parameters will be as per industry (EMS) and societal recommended guidelines (International Society for Medical Shockwave Treatment, ISMST) with intensity ranging from 2-4 bar pressure for a minimum of 2000 pulses using a 15mm diameter applicator head, at a frequency ranging from 4-10Hz based on comfort. As is standard clinical practice, the intent is to deliver the highest tolerable energy based on a progressive increase in bar pressure, a term referred to by ISMST as ‘pain-adapted dosing’. As well as aiming for maximum bar pressure, we will seek to deliver a minimum total energy treatment dose across all 3 sessions. For this study for the purpose of quantifying a per protocol energy dose, we will target a minimum total energy dose of 500 mJ/mm^2. The Master Touch unit can convert bar pressure into energy flux density (mJ/mm^2), which when multiplied by the number of pulses delivered, computes the total sessional energy dose. To reach 500 mJ/mm^2 across 3 sessions, an average bar pressure above 2.2 is required. This places this dose in a clinically therapeutic range. If it is evident that the cumulative dose is going to be short of the targeted 500 mJ/mm^2, the clinician may increase the number of pulses in subsequent sessions (e.g. to 2500), however the priority is always to deliver the maximum peak energy dose. If participants do not receive the minimum dose across the 3 sessions, a 4th ‘top-up’ session will be offered. If a top-up session is required, this will be matched with a top-up session to an equal number of participants in the sham group. Sessions will be booked in consecutive weeks in advance however we will allow missed sessions to be caught up with treatment gaps not exceeding 2 weeks. An advice sheet detailing flare management, footwear and activity recommendations will be provided to both groups.

Sponsors

Menzies Institute for Medical Research, University of Tasmania
Lead SponsorUniversity

Study design

Allocation
Randomised controlled trial
Intervention model
Parallel
Primary purpose
Treatment
Masking
Blinded (masking used) (Subject, Investigator, Outcomes Assessor)

Eligibility

Sex/Gender
All
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

Inclusion: (i) aged >=18yrs, (ii) pain under the heel on most days aggravated by weightbearing, for at least 3 months, (iii) pain level > 30 on a 100mm pain visual analogue scale (VAS, 0 no pain, 100 worst possible pain), (iv) plantar calcaneal BML on PD-FS sagittal MRI > 22mm^2 (22mm^2 is the Least Significant Change, as calculated from our preliminary data).

Exclusion criteria

Exclusion: (i) other lower limb pain or injury affecting mobility or participation in the past 3 months, (ii) past foot surgery or fracture involving the ankle, hind or midfoot, excluding avulsion injuries confirmed on X-ray, (iii) injection into the heel in last 3 months (iv) previous shockwave treatment, (v) diabetes or inflammatory disease, (vi) fibromyalgia, (vii) contraindication to MRI^, (viii) currently receiving professional treatment*, (ix) lower limb neurological disease, (x) vascular disease affecting lower limbs, (xi) sciatica in last 6 months, (xii) contraindication to having shockwave treatment (Table 1), (xiii) past or current bisphosphonate use, and (xiv) unwilling or unable to commit to full treatment course or complete questionnaires online. *Discontinuing current treatment with a 2-week washout for non-steroidal anti-inflammatory use, 6-weeks for glucocorticoid use, or 3-week wash-out for conservative professional interventions such as manual therapy, would void this exclusion. Participants who maintain a stable approach in the preceding 6 weeks to ongoing self-administered treatments such as footwear or orthotic use or exercise, may continue with those interventions and maintain eligibility. ^Although not an absolute contra-indication, we will exclude pregnant participants. If there is any doubt about pregnancy status we will request participants undergo a urine pregnancy screening test before proceeding to MRI. Table 1. Contraindications to shockwave therapy Anti-coagulant therapy, haemhorrhagic conditions Local infection Wound/ skin lesions Malignancy Impaired circulation/ ischaemic conditions Prosthetic device in treatment area

Outcome results

None listed

Source: ANZCTR · Data processed: Feb 4, 2026