Table 1.

Overview of PROSPER exercise intervention, as per TIDIER Criteria

TIDieR Items	Description
Brief Name	PROSPER (PRevention Of Shoulder ProblEms Trial)
Why	Breast cancer treatments can affect the muscles, nerves, and lymphatic vessels in the shoulder and upper body, leading to reduced range of movement, muscle weakness, pain, and reduced upper limb function. Structured exercise programmes, started within days or weeks from surgery, may improve shoulder movement, strength, and function.
What	A physiotherapy-led 12-month exercise programme.
Materials: Participants	Every trial participant in the exercise arm is given “Your Physiotherapy Folder”, a small A5 folder containing a detailed description of all exercises, advice about surgical recovery, physical activity, postoperative complications and returning to daily activities. It also contains an exercise diary, a goal-setting sheet with a contract, and a ‘hurdles/facilitators’ brainstorming sheet. Participants are provided with resistance bands (Thera-band© tubing) for strengthening exercises and can be provided with protective goggles if this is a local NHS Trust policy.
Materials: Physiotherapists	Each PROSPER physiotherapist is provided with a comprehensive training manual (A4 ring binder and flexible bound copy), a participant folder and copy of training presentation slides. Box files are given containing a selection of resistance bands and supplies of paperwork such as treatment logs and instruction laminates.
Procedures	All participants follow usual care for the first 7 days after surgery (restricting shoulder movement to 90 degrees of flexion and abduction). For intervention participants, the first physiotherapy appointment is at 7–10 days after surgery. The assessment includes previous medical history, shoulder range of movement, shoulder strength (from 4 weeks), posture check, observation of wound and screening questions for pain and lymphoedema. Participants are provided with a folder (‘Your Physiotherapy Folder’), from which the physiotherapist and the participant jointly select exercises based on the assessment and participant preference. Physiotherapists use motivational interviewing techniques to help each participant to set goals, explore confidence to exercise, problem-solve any hurdles and to facilitate ongoing motivation and exercise adherence at subsequent sessions. All exercises are detailed in Fig. 2. Any exercises prescribed to the patient should be performed at home.
Who provides	NHS physiotherapists from various backgrounds, including musculoskeletal rehabilitation, women’s health and surgical care. Physiotherapists have varying experience of oncology rehabilitation, ranging from limited to extensive clinical experience. All physiotherapists receive 4–5 h of intervention training.
How	Three individual face-to-face appointments and up to three individual flexible appointments delivered either face-to-face or by telephone.
Where	Clinic appointments are mostly located in physiotherapy outpatient clinics within secondary care UK NHS Trusts. The home exercise programme is conducted independently at the participant’s home.
When	Contacts: 3 face-to-face appointments at recommended time points: 7–10 days, 4–6 weeks, and 12 weeks after surgery. Participants can have an additional three flexible appointments at any time, either via face-to-face or by telephone. The first appointment is 60 min, with all subsequent appointments lasting 30 min.
How much	See Table 3.
Tailoring	The intervention can be individually tailored to each participant: • Selection of starting exercises is a joint-decision making process, based on the physiotherapist’s assessment and participant preference. • Exercise progression (frequency, level, resistance, repetitions, and sets) is a joint-decision making process, depending on current progress, level of pain and ability. • Type and level of physical activity will vary by participant. • Number, timing and mode of the three additional appointments is flexible. • The integrated behavioural strategies may feature more prominently for patients with low confidence and motivation to exercise. Identifying and problem solving barriers to exercise will be highly specific and individualised. • Optional use of manual therapy for cording and additional exercises for specific issues such as fist pumps for lymphoedema.
Modifications	The intervention was modified after qualitative interviews and piloting. Key changes included: (1) change of name from “Your Exercise Folder” to “Your Physiotherapy Folder”; (2) reduction in number of exercises within longer menu; (3) change in terminology of “barriers and facilitators” to “hurdles and facilitators”. Other adaptations included the provision of clear laminated materials as visual aids e.g. pictorial guides for the BORG scale, pain visual analogue scale and treatment flowcharts.
	Intervention Fidelity
How well: Training	Evaluation forms are completed by physiotherapists after PROSPER intervention training. Asked to return completed forms anonymously to trial office. All aspects of training delivery and trial materials are evaluated.
How well: Physiotherapist (Planned)	Training emphasises adherence to the PROSPER standardised intervention manual. A senior research physiotherapist (HR), responsible for training, conducts quality assurance checks (QA) by observing at least one treatment session with each participating physiotherapist. Performance and adherence to the standardised protocol is judged against pre-defined criteria. Where treatment fidelity is not acceptable, feedback is given and another QA visit is arranged. QA criteria includes ensuring that the physiotherapist demonstrates each exercise with participants.
How well: Participants	Intervention adherence: participants are asked to complete and return exercise diaries to record type and amount of exercises performed over the duration of the study. The physiotherapist reviews this exercise diary with the patient at session to monitor adherence and review progress. These diaries are returned to the trial office for analysis once a participant has been discharged.
How well: (Actual)	Data on intervention fidelity will be reported with main trial findings.
Additional criteria as per CERT Criteria
HOW: delivery	Item 7: Decision rules for progressing the exercise program: Progression of shoulder ROM exercises is decided jointly between the patient and the physiotherapist when they can complete the desired number of repetitions comfortably. For strength, each exercise is assessed by performing 2 repetitions and asking the patient to rate their perceived exertion on the modified BORG scale. If their rated exertion is less than 5, the resistance is progressed.
	Item 6: Details of motivation strategies: Motivational interviewing techniques are used provide feedback on the exercise diary, explore implementation intentions, collaboratively set goals, and brainstorm hurdles to exercise.
	Item 8: Each exercise is described so it can be replicated e.g. illustrations, photographs: All exercises are described in detail using multiple photographs and descriptive text underneath the photographs.
	Item 10: Non exercise components: In addition to the exercise programme, physiotherapists may use manual therapy (massage and cord release) to treat soft-tissue tightness or cording. These techniques can be taught to the patient and/or a relative so that they can be performed at home.
	Item 11: How adverse events that occur during exercise are documented and managed: Any adverse event that occurs as a direct result of the PROSPER exercise intervention will be recorded and reported, and reviewed by the Trial Steering and Data Monitoring Committee (TSC and DMC).