Table 1 Eligibility criteria

Inclusion Criteria

  Initial Phone Screening

    1. Reports of relatively localised (defined as an area smaller than a tennis ball) ischial tuberosity region pain [3] of gradual onset and at least 3 months in duration

    2. Willingness to participate in six sessions of intervention over a 12-week period

    3. Age between 18 and 65 inclusive

    4. Fluency in English sufficient to complete questionnaires and to enable understanding to the intervention

    5. Agreeing to refrain from other interventions for the treatment period of the trial, aside from consultation with medical practitioners, and medication

  Clinical examination screening

    6. A history of increased tendon load precipitating the onset of symptoms determined based on clinical interview

    7. Reproduction of ischial tuberosity region pain with three or more of the following loading/compressive tests:

      • Single-leg arabesque (Fig. 2)

      • Supine single leg bridge with heel on standardised height platform (bent knee) (Fig. 3)

      • Self-reported PHT symptoms with prolonged sitting < 30 min

      • Modified bent-knee hamstring stretch test [9]

Exclusion Criteria

  Initial Phone Screening

    1. Previous surgery to the hamstring complex, as we wish to study treatment effects independent to the effects of surgical procedures

    2. Previous injection to the hamstring tendon within the previous 6 weeks, as we wish to study treatment effects independent to the effects of injections

    3. Treatment with ESWT for PHT in the last 3 months, [26] as this may influence progress during the trial

    4. Contraindications to receiving ESWT [49]

    5. Current pregnancy, or recent childbirth (within 6 months) as this could impair ability to undertake testing and intervention

    6. Diagnosis with autoimmune disease as these conditions may have a negative impact on tendon

    7. Already received more than two sessions of physiotherapy with any of the trial physiotherapists prior to enrolment, as these therapists are likely to use components of the trial treatment protocol on their clinical caseload

    8. An active compensation claim for the injury, as this may influence the response to treatment [50]

    9. Planned absence for a period of > 2 weeks during the treatment period (such as extended holiday)

  Clinical examination screening

    10. Pain that is predominantly due to lumbar dysfunction including lumbar spine radiculopathy, [51] or lumbar spine somatic referral (Additional file 1)

    11. Pain that is reasoned from clinical examination to be predominantly due to other structures or conditions, including sciatic nerve entrapment, ischiofemoral impingement, hip joint, local sciatic nerve irritation, and adductor magnus tendinopathy (Additional file 1)