The efficacy of radial shockwave therapy compared with sham shockwave therapy in insertional Achilles tendinopathy. A randomised controlled trial

INTERVENTION: Radial shockwave therapy (rSWT): rSWT will be administered by an adequately trained physiotherapist. The participant will receive a 3000‐shock dose of rSWT (Chattanooga device) applied to the most painful area on the affected side Achilles tendon. Gel will be used to conduct pressure waves to the tendon. Intensity of application will start on two bars of pressure, with frequency set to continuous and eight per second. The target self‐reported pain will be >4/10 until the highest tolerable pain (numerical pain rating scale, 0=no pain, 10=worst pain imaginable). If self‐reported pain drops below 5/10 the rSWT probe will be moved to a different region within the region of interest (area 2cm squared surrounding the starting location). If the pain remains below 5/10 at all parts within the region of interest the rSWT pressure setting will be progressed from two bar of pressure (this will always be the starting point) up to and including five bar of pressure (the maximum in the machine being used) so as to achieve the desired self‐reported pain output. This process will be repeated as necessary until the shock dose of 3000 is completed (at 10 Hz, so the treatment lasts for 5 minutes). Participants will receive an identical rSWT treatment on three occasions (baseline, and approx. week 1 and 2), each separated by a approximaly 7 days (minimum 5 days and maximum 10 days). Post rSWT treatment: Immediately after the rSWT, participants will be asked whether they believe they were in the intervention or placebo group. After that, an appropriately trained researcher, who is blind to treatment allocation will deliver advice and a 12‐week exercise program to all participants. This includes an evidence‐ CONDITION: Musculoskeletal ‐ Other muscular and skeletal disorders Physical Medicine / Rehabilitation ‐ Physiotherapy Tendinopathy; ; Tendinopathy PRIMARY OUTCOME: Global rating of change measured with the the Global Rating of Change Scale (GROC). The GROC is an 11‐point scale where participants rate perceived change in their condition. The categories include Worse, No Change, or Better. If they indicate worse or better they are asked to quantify this on a 5 point scale from Slightly Better/Worse to Very Much Better/Worse. [baseline in person and 6 and 12 (primary endpoint) weeks via email or text link to online questionnaire] Pain and function will be assessed with VISA‐A score (this is a composite instriment measuring both pain and function). The VISA‐A is a disease specific and validated tool for assessing Achilles tendon pain and function.[baseline in person and 6 and 12 (primary endpoint) weeks via email or text link to online questionnaire.] SECONDARY OUTCOME: ; Overall pain intensity last 24 hours: Measured using the 100 mm visual analogue scale (VAS), participants will rate the worst pain during the last 24 hours (zero = no pain; 100 = worst pain possible).[a/ Baseline, week 1 and week 2 (before each rSWT session) face to face ; b/ Week 6 and 12 via email or text link to online questionnaire ; b/ Self‐reported and recorded by participants for 7 consecutive days following each rSWT application. ] ; Adverse events over the last 6 weeks: An adverse event is defined as any unfavourable or unintended diagnosis, sign, symptom, or disease associated with the study which may or may not be related to the intervention (e.g. tendon rupture, fall, injury, or change in medical status). It will be measured using an Adverse events questionnaire, which was designed specifically for this study.[6 and 12 weeks via email or text link to online questionnaire] Catastrophising: The Pain Catastrophising Scale is a validated questionnaire used to measure pain catastrophisation.[baseline in person and 6 and 12 weeks via email or text link to online questionnaire] Exercise adherence: Participants will record the number of exercise sessions completed each week over the previous six weeks (adherence is the percentage of prescribed sessions that are completed)[6 and 12 weeks via email or text link to online questionnaire] Fear avoidance: The Tampa Kinesiophobia Scale is a validated questionnaire used to measure fear‐avoidance.[baseline in person and 6 and 12 weeks via email or text link to online questionnaire] Health‐related quality of life: Measured with the EuroQol 5D‐5L which is a composite outcome measuring five domains AND overall health. The EuroQol 5D‐5L is a validated and reliable tool, including five domains (mobility, self‐care, usual activities, pain/discomfort and anxiety/depression), and a rating of overall health state from 0 (worst health state imaginable) to 100 (best imaginable health state) using a VAS.[baseline in person and 6 and 12 weeks via email or text link to online questionnaire] Healthcare use: Participants will be asked to answer yes or no to whether they have used any health services or co‐interventions over the last 6 weeks. if they answer yes details will becollected via a follow up telephone call. [6 and 12 weeks via email or text link to online questionnaire] Mechanosensory sensitivity measured using pressure pain threshold at the site of rSWT application (most affected insertional Achilles tendon) and the opposite elbow. This outcome will be collected pre and post each shockwave session. A pressure algometer is used to measure pressure pain threshold.[Baseline, week 1 and week 2 (before and after each rSWT session)] Pain self efficacy: Assessed with the pain self‐efficacy questionnaire (PSEQ). The PSEQ measures how confident a patient is in undertaking a range of activities despite their pain[baseline in person and 6 and 12 weeks via email or text link to online questionnaire] Pain with a standardised loading protocol reported on a 100 mm visual analogue scale (zero = no pain; 100 = worst pain possible). Participants will perform 3 single leg calf raises over a step (1 second up and 1 second down, in time with a metronome) and 5 single leg hops (in time with metronome set at 120 bpm [2 hops per second]) in a randomised order. These measures will be assessed (in a randomised order) pre and post rSWT application at baseline, week 1 and 2, as well as self reported by patients everyday for 7 days post rSWT application. For self report measures, participants will be asked to perform the tasks in a random order at the same time (10 to 11am) everyday. [Baseline, week 1 and week 2 (before and after each rSWT session) via face to face, and self‐reported and recorded by participants for 7 consecutive days following each rSWT application. ] Productivity (including absenteeism and presentism) will be measured using the ‘iMTA Productivity Cost Questionnaire’ [baseline in person and 6 and 12 weeks via email or text link to online questionnaire] The level of physical activity in the previous week: Evaluated using the 7‐day Recall Physical Activity Questionnaire, a valid and reliable tool. Participants will be asked to recall time spent sleeping and doing physical activity (work, leisure, household activities) over the past 7 days.[baseline in person and 6 and 12 weeks via email or text link to online questionnaire] INCLUSION CRITERIA: Aged 18 years or older >3 months of pain at the insertion of the Achilles to the posterior calcaneal surface Primary complaint of insertional Achilles pain on one or both lower limbs Clinical diagnosis of insertional Achilles tendinopathy based on the following criteria: o Gradual onset pain in the relevant area; o Pain during or after Achilles tendon loading activities (e.g. walking, running) Ankle joint examination is normal and passive plantar‐flexion is painfree; Confirm diagnosis with ultrasound imaging of the Achilles tendon. One or more of the following features present in the insertion area: (i) thickening of the anteroposterior tendon insertion; and/or (ii) hypoechoic regions with or without thickening/fluid within the retrocalcaneal bursa