Pain Neuroscience Education and Therapeutic Exercise as a Treatment for Breast Cancer Survivors Living With Sequelae

Pain intensity will be measured using the visual analog scale (VAS), participants will report their pain intensity within a range of 0 to 100 millimeters, with 0 being no pain and 100 being the maximum pain.

Participants will report the number of days per week with pain.

Kinesiophobia will be measured through the Tampa Kinesiophobia Scale Spanish version with 11 items (TSK-11V). It consists of a self-report instrument with 11 items related to fear of movement or injury relapse. Each ítem is measured on a Likert-type scale between 1 and 4 points, being 1 totally disagree and 4 totally agree, being able to obtain a total between a range of 11 to 44 final points. The higher the score, the higher the level of kinesiophobia.

Physical functionality will be measured through the Upper Limb Functional Index scale (ULFI-Sp), which consists of a list of 25 items. Each item is scored on a 3-point scale by filling in a box, so that filling in the whole box means strongly agree, half a box means partially agree, and leaving it empty means strongly disagree, giving it a score of 1, 0.5 and 0 points respectively. The total score (25 points maximum) is multiplied by 4 to obtain a score based on 100 points, of which 0 would represent no functional limitation and 100 maximum limitation. The first 16 items refer to common functional activities, while the other 9 focus on activities involving the use of the upper limb.

Active joint range of motion (active ROM) will be measured as part of the physical function assessment of the patient's upper limb. Flexion, horizontal flexion, extension, internal rotation, external rotation and abduction of both shoulders will be measured. Active ROM will be measured using a BASELINE® brand 12-inch shoulder goniometer. Three goniometric measurements will be taken per movement, and the average will be taken to obtain a value of the active ROM between a range of 0 and 180 degrees.

An initial survey with 2 sections will be applied: the first will collect information on sociodemographic variables such as: age, marital status, occupation, level of schooling, weight, height, BMI, habits (alcohol and tobacco) and comorbidities. The second will contain questions on the clinical characteristics of breast cancer such as: number of months with pain, time since initial diagnosis, time elapsed and stage of breast cancer at diagnosis, type of breast cancer according to histological classification, hormone receptor status, location of breast cancer (right, left or bilateral), type of surgery and other treatments (radiotherapy, chemotherapy, hormone therapy or inmunotherapy), the region of pain (axilla, shoulder, arm or thorax).

The DN4 questionnarie will be used to discriminate between neuropathic and nociceptive type of pain. The DN4 questionnaire consists of a total of 10 items grouped in 4 sections. The first seven items are related to the quality of pain (burning, painful cold, electric shocks) and its association to abnormal sensations (tingling, pins and needles, numbness, itching). The other 3 items are related to neurological examination in the painful area (touch hypoesthesia, pinprick hypoesthesia, tactile allodynia). A score of 1 is given to each positive item and a score of 0 to each negative item. The total score is calculated as the sum of all 10 items, and the cut-off value for the diagnosis of neuropathic pain is a total score of 4/10.

To evaluate central sensitization related symptoms part A of the Spanish Central Sensitization Inventory (CSI) will be used. Part A of the CSI assesses 25 health-related symptoms common to central sensitization, with total scores ranging from 0 to 100. . A total score of 40 or higher indicates the presence of central sensitization.

To evaluate possible nociplastic pain, the clinical criteria for nociplastic pain affecting the musculoeskeletal system propose by the International Association for The Study of Pain (IASP) Terminology Task Force (TTF) will be used. It consists of 4 items to clinically evaluate: the type of pain (if greater than 3 months, its distribution and the presence or not of nociceptive type of pain), history of hypersensitivity in the region of pain, presence of comorbidities (sensitivity to sound or light, sleep problems, fatigue or cognitive problems), evoked pain hypersensitivity in the region of pain (static mechanical allodynia, static dynamic allodynia, allodynia to heat or cold). Presence of item 1 and 4 is classifed as possible nociplastic pain, and all of the above (item 1, 2, 3 and 4) as probable nociplastic pain.